RESUMEN

We report here on the structure-activity relationships of hybrids combining 3-descladinosyl clarithromycin with quinolones linked by extended diamine connectors. Several hybrids, exemplified by 23Bc, 23Be, 23Bf, 26Be, and 30Bc, not only restored potency against inducibly resistant pathogens but also exhibited significantly enhanced activities against constitutively resistant strains of Staphylococcus pneumoniae and Staphylococcus pyogenes, which express high-level resistance independent of clarithromycin or erythromycin induction. Additionally, the novel hybrids showed susceptibility against Gram-negative Haemophilus influenzae. Notably, hybrid 23Be demonstrated dual modes of action by inhibiting both protein synthesis and DNA replication in vitro and in vivo. Given these promising characteristics, 23Be emerges as a potential candidate for the treatment of community-acquired bacterial pneumonia.

Asunto(s)

Antibacterianos , Claritromicina , Diseño de Fármacos , Pruebas de Sensibilidad Microbiana , Relación Estructura-Actividad , Claritromicina/farmacología , Claritromicina/química , Claritromicina/síntesis química , Antibacterianos/farmacología , Antibacterianos/síntesis química , Antibacterianos/química , Estructura Molecular , Diaminas/química , Diaminas/farmacología , Diaminas/síntesis química , Haemophilus influenzae/efectos de los fármacos , Oximas/química , Oximas/farmacología , Oximas/síntesis química , Relación Dosis-Respuesta a Droga , Humanos , Animales , Streptococcus pyogenes/efectos de los fármacos , Farmacorresistencia Bacteriana/efectos de los fármacos

RESUMEN

INTRODUCTION: H. influenzae carriage may evolve into respiratory or systemic infections. However, no surveillancesystem is in place in Belgium to monitor carriage strains. MATERIAL AND METHODS: This study provides a detailed description of H. influenzae strains isolated from both carriage and lower respiratory infections, collected during a six-month national surveillance. Subsequently, a comparison is conducted with invasive isolates collected during the same period at the National Reference Centre (NRC). RESULTS AND DISCUSSION: From November 2021 to April 2022, 39 clinical laboratories collected 142 and 210 strains of H. influenzae from carriage and infection, respectively, and 56 strains of blood were submitted to the NRC. In each group, the biotype II comprised more than 40%, followed by biotypes III and I. The majority of strains were non-typeable H. influenzae, with a notable increase in the number of encapsulated strains in the invasive group (14.3% vs. 1-2%). A beta-lactamase was identified in 18.5% and 12.5% of surveillance and invasive strains, respectively. Resistance to the amoxicillin-clavulanic acid combination accounted for 7% in the surveillance strains and 10.7% in invasive strains. The overall resistance to third-generation cephalosporins at 1.2% is consistent with rates observed in other European countries. Of particular significance is the identification of mutations in the ftsI gene in both carriage and infected strains, which are associated with high-level beta-lactam resistance. CONCLUSION: NRC must engage in regular and systematic monitoring of beta-lactam susceptibility of H. influenzae to guarantee safe empiric therapy in severe cases and identify potential transitions from low-level to high-level resistance in the future.

Asunto(s)

Antibacterianos , Portador Sano , Infecciones por Haemophilus , Haemophilus influenzae , Pruebas de Sensibilidad Microbiana , Infecciones del Sistema Respiratorio , Humanos , Bélgica/epidemiología , Haemophilus influenzae/genética , Haemophilus influenzae/aislamiento & purificación , Haemophilus influenzae/efectos de los fármacos , Haemophilus influenzae/clasificación , Infecciones por Haemophilus/microbiología , Infecciones por Haemophilus/epidemiología , Infecciones del Sistema Respiratorio/microbiología , Infecciones del Sistema Respiratorio/epidemiología , Portador Sano/microbiología , Portador Sano/epidemiología , Masculino , Femenino , Adulto , Persona de Mediana Edad , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Preescolar , Niño , Adolescente , Anciano , Adulto Joven , Lactante , Anciano de 80 o más Años

RESUMEN

BACKGROUND: Aminopenicillins are recommended agents for non-invasive Haemophilus influenzae infections. One of the mechanisms of resistance to ß-lactams is the alteration of the transpeptidase region of penicillin binding protein 3 (PBP3) which is caused by mutations in the ftsI gene. It was shown that exposure to beta-lactams has a stimulating effect on increase of prevalence of H. influenzae strains with the non-enzymatic mechanism of resistance. OBJECTIVES: The aim of our study was to compare the mutational potential of ampicillin and cefuroxime in H. influenzae strains, determination of minimum inhibitory concentration and the evolution of mutations over time, focusing on amino acid substitutions in PBP3. METHODS: 30 days of serial passaging of strains in liquid broth containing increasing concentrations of ampicillin or cefuroxime was followed by whole-genome sequencing. RESULTS: On average, cefuroxime increased the minimum inhibitory concentration more than ampicillin. The minimum inhibitory concentration was increased by a maximum of 32 fold. Substitutions in the PBP3 started to appear after 15 days of passaging. In PBP3, cefuroxime caused different substitutions than ampicillin. CONCLUSIONS: Our experiment observed differences in mutation selection by ampicillin and cefuroxime. Selection pressure of antibiotics in vitro generated substitutions that do not occur in clinical strains in the Czech Republic.

Asunto(s)

Sustitución de Aminoácidos , Ampicilina , Antibacterianos , Cefuroxima , Haemophilus influenzae , Pruebas de Sensibilidad Microbiana , Mutación , Proteínas de Unión a las Penicilinas , Cefuroxima/farmacología , Ampicilina/farmacología , Haemophilus influenzae/genética , Haemophilus influenzae/efectos de los fármacos , Proteínas de Unión a las Penicilinas/genética , Proteínas de Unión a las Penicilinas/metabolismo , Antibacterianos/farmacología , Humanos , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Infecciones por Haemophilus/microbiología , Secuenciación Completa del Genoma , Evolución Molecular , Selección Genética , Pase Seriado

RESUMEN

OBJECTIVES: This study aimed to explore the prevalence of macrolide resistance and the underlying resistance mechanisms in Haemophilus influenzae (n = 2556) and Haemophilus parainfluenzae (n = 510) collected between 2018 and 2021 from Bellvitge University Hospital, Spain. METHODS: Antimicrobial susceptibility was tested by microdilution. Whole-genome sequencing was performed using Illumina MiSeq and Oxford Nanopore technologies, and sequences were examined for macrolide resistance determinants and mobile genetic structures. RESULTS: Macrolide resistance was detected in 67 H. influenzae (2.6%) and 52 (10.2%) H. parainfluenzae strains and associated with resistance to other antimicrobials (co-trimoxazole, chloramphenicol, tetracycline). Differences in macrolide resistance existed between the two species. Acquired resistance genes were more prevalent in H. parainfluenzae (35/52; 67.3%) than in H. influenzae (12/67; 17.9%). Gene mutations and amino acid substitutions were more common in H. influenzae (57/67; 85%) than in H. parainfluenzae (16/52; 30.8%). Substitutions in L22 and in 23S rRNA were only detected in H. influenzae (34.3% and 29.0%, respectively), while substitutions in L4 and AcrAB/AcrR were observed in both species. The MEGA element was identified in 35 (67.3%) H. parainfluenzae strains, five located in an integrative and conjugative element (ICE); by contrast, 11 (16.4%) H. influenzae strains contained the MEGA element (all in an ICE). A new ICEHpaHUB8 was described in H. parainfluenzae. CONCLUSIONS: Macrolide resistance was higher in H. parainfluenzae than in H. influenzae, with differences in the underlying mechanisms. H. parainfluenzae exhibits co-resistance to other antimicrobials, often leading to an extensively drug-resistant phenotype. This highlights the importance of conducting antimicrobial resistance surveillance.

Asunto(s)

Antibacterianos , Farmacorresistencia Bacteriana , Infecciones por Haemophilus , Haemophilus influenzae , Haemophilus parainfluenzae , Macrólidos , Pruebas de Sensibilidad Microbiana , Secuenciación Completa del Genoma , Haemophilus parainfluenzae/genética , Haemophilus parainfluenzae/efectos de los fármacos , Macrólidos/farmacología , Haemophilus influenzae/efectos de los fármacos , Haemophilus influenzae/genética , Antibacterianos/farmacología , Infecciones por Haemophilus/microbiología , Humanos , Farmacorresistencia Bacteriana/genética , España/epidemiología , Mutación

RESUMEN

BACKGROUND: Bacterial etiologies of acute otitis media (AOM) have shifted from the introduction of pneumococcal conjugate vaccines (PCVs), antibiotic selection and competition among species. We characterized Streptococcus pneumoniae ( Spn ), Haemophilus influenzae ( Hflu ) and Moraxella catarrhalis ( Mcat ) in the nasopharynx during well-child healthy visits and at the onset of AOM, and in middle ear fluid (MEF) of children with AOM to assess anticipated effects of higher-valency PCVs (PCV15 and PCV20). METHODS: From September 2021 to September 2023, we conducted a prospective longitudinal cohort study of PCV13 immunized children 6-36 months old. MEF was collected via tympanocentesis. Serotyping and antibiotic susceptibility testing were performed on Spn , Hflu and Mcat isolates. RESULTS: We obtained 825 nasopharyngeal and 216 MEF samples from 301 children. The order of frequency of nasopharyngeal colonization was Mcat , Spn and Hflu ; Hflu was the predominant otopathogen in MEF. Among Spn isolates, non-PCV15, non-PCV20 serotypes predominated in the nasopharynx and in MEF; the most frequent serotype was 35B. Among MEF samples, 30% of Spn isolates were amoxicillin nonsusceptible; 23% of Hflu isolates and 100% of Mcat isolates were ß-lactamase-producing. CONCLUSION: The majority of Spn isolates among young children were non-PCV15, non-PCV20 serotypes, especially serotype 35B; therefore, the impact of higher-valency PCVs in reducing pneumococcal colonization or AOM is expected to be limited. Hflu continues to be the most frequent AOM pathogen. Antibiotic susceptibility data suggest a high dose of amoxicillin/clavulanate or alternative drugs that are effective against contemporary mix of otopathogens could be considered for optimal empiric selection to provide the best efficacy.

Asunto(s)

Moraxella catarrhalis , Nasofaringe , Otitis Media , Vacunas Neumococicas , Streptococcus pneumoniae , Humanos , Vacunas Neumococicas/administración & dosificación , Otitis Media/microbiología , Otitis Media/prevención & control , Otitis Media/epidemiología , Lactante , Preescolar , Nasofaringe/microbiología , Estudios Prospectivos , Streptococcus pneumoniae/inmunología , Streptococcus pneumoniae/efectos de los fármacos , Streptococcus pneumoniae/aislamiento & purificación , Estudios Longitudinales , Femenino , Moraxella catarrhalis/efectos de los fármacos , Moraxella catarrhalis/aislamiento & purificación , Masculino , Haemophilus influenzae/efectos de los fármacos , Haemophilus influenzae/aislamiento & purificación , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Vacunas Conjugadas/administración & dosificación , Infecciones Neumocócicas/prevención & control , Infecciones Neumocócicas/microbiología , Infecciones Neumocócicas/epidemiología , Pruebas de Sensibilidad Microbiana , Enfermedad Aguda

RESUMEN

A decreased chloramphenicol susceptibility in Haemophilus influenzae is commonly caused by the activity of chloramphenicol acetyltransferases (CATs). However, the involvement of membrane proteins in chloramphenicol susceptibility in H. influenzae remains unclear. In this study, chloramphenicol susceptibility testing, whole-genome sequencing, and analyses of membrane-related genes were performed in 51 H. influenzae isolates. Functional complementation assays and structure-based protein analyses were conducted to assess the effect of proteins with sequence substitutions on the minimum inhibitory concentration (MIC) of chloramphenicol in CAT-negative H. influenzae isolates. Six isolates were resistant to chloramphenicol and positive for type A-2 CATs. Of these isolates, A3256 had a similar level of CAT activity but a higher chloramphenicol MIC relative to the other resistant isolates; it also had 163 specific variations in 58 membrane genes. Regarding the CAT-negative isolates, logistic regression and receiver operator characteristic curve analyses revealed that 48T > G (Asn16Lys), 85 C > T (Leu29Phe), and 88 C > A (Leu30Ile) in HI_0898 (emrA), and 86T > G (Phe29Cys) and 141T > A (Ser47Arg) in HI_1177 (artM) were associated with enhanced chloramphenicol susceptibility, whereas 997G > A (Val333Ile) in HI_1612 (hmrM) was associated with reduced chloramphenicol susceptibility. Furthermore, the chloramphenicol MIC was lower in the CAT-negative isolates with EmrA-Leu29Phe/Leu30Ile or ArtM-Ser47Arg substitution and higher in those with HmrM-Val333Ile substitution, relative to their counterparts. The Val333Ile substitution was associated with enhanced HmrM protein stability and flexibility and increased chloramphenicol MICs in CAT-negative H. influenzae isolates. In conclusion, the substitution in H. influenzae multidrug efflux pump HmrM associated with reduced chloramphenicol susceptibility was characterised.

Asunto(s)

Sustitución de Aminoácidos , Antibacterianos , Proteínas Bacterianas , Cloranfenicol , Haemophilus influenzae , Humanos , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Cloranfenicol/farmacología , Cloranfenicol O-Acetiltransferasa/genética , Cloranfenicol O-Acetiltransferasa/metabolismo , Resistencia al Cloranfenicol/genética , Farmacorresistencia Bacteriana Múltiple/genética , Infecciones por Haemophilus/microbiología , Haemophilus influenzae/efectos de los fármacos , Haemophilus influenzae/genética , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Pruebas de Sensibilidad Microbiana , Secuenciación Completa del Genoma

RESUMEN

The COVID-19 pandemic has altered the infection landscape for many pathogens. This retrospective study aimed to compare Haemophilus influenzae (H. influenzae) infections in pediatric CAP patients hospitalized before (2018-2019) and during (2020-2022) the COVID-19 pandemic. We analyzed the clinical epidemiology and antimicrobial resistance (AMR) patterns of H. influenzae from a tertiary hospital in southwest China. A total of 986 pediatric CAP patients with H. influenzae-associated infections were included. Compared to 2018, the positivity rate increased in 2019 but dropped significantly in 2020. Although it rose in the following 2 years, the rate in 2022 remained significantly lower than in 2019. Patients' age during the pandemic was significantly higher than in 2018 and 2019, while gender composition remained similar across both periods. Notably, there were significant changes in co-infections with several respiratory pathogens during the pandemic. Resistance rates of H. influenzae isolates to antibiotics varied, with the highest resistance observed for ampicillin (85.9%) and the lowest for cefotaxime (0.0%). Resistance profiles to various antibiotics underwent dramatic changes during the COVID-19 pandemic. Resistance to amoxicillin-clavulanate, cefaclor, cefuroxime, trimethoprim-sulfamethoxazole, and the proportion of multi-drug resistant (MDR) isolates significantly decreased. Additionally, MDR isolates, alongside isolates resistant to specific drugs, were notably prevalent in ampicillin-resistant and ß-lactamase-positive isolates. The number of pediatric CAP patients, H. influenzae infections, and isolates resistant to certain antibiotics exhibited seasonal patterns, peaking in the winter of 2018 and 2019. During the COVID-19 pandemic, sharp decreases were observed in February 2020, and there was no resurgence in December 2022. These findings indicate that the COVID-19 pandemic has significantly altered the infection spectrum of H. influenzae in pediatric CAP patients, as evidenced by shifts in positivity rate, demographic characteristics, respiratory co-infections, AMR patterns, and seasonal trends.

Asunto(s)

Antibacterianos , COVID-19 , Infecciones Comunitarias Adquiridas , Infecciones por Haemophilus , Haemophilus influenzae , Humanos , COVID-19/epidemiología , COVID-19/complicaciones , Masculino , Femenino , Haemophilus influenzae/efectos de los fármacos , Haemophilus influenzae/aislamiento & purificación , Niño , Preescolar , Infecciones por Haemophilus/epidemiología , Infecciones por Haemophilus/tratamiento farmacológico , Infecciones por Haemophilus/microbiología , Estudios Retrospectivos , Infecciones Comunitarias Adquiridas/epidemiología , Infecciones Comunitarias Adquiridas/tratamiento farmacológico , Infecciones Comunitarias Adquiridas/microbiología , Lactante , China/epidemiología , Antibacterianos/uso terapéutico , Hospitalización , Adolescente , Pandemias , Coinfección/epidemiología , Coinfección/tratamiento farmacológico , Coinfección/microbiología , SARS-CoV-2/aislamiento & purificación , SARS-CoV-2/efectos de los fármacos , Farmacorresistencia Bacteriana

RESUMEN

Asthma is a chronic and heterogeneous disease affecting the lungs and respiratory tract. In particular, the neutrophil subtype of asthma was described as persistent, more severe, and corticosteroid-resistant. Growing evidence suggested that nontypeable Haemophilus influenzae (NTHi) infection contributes to the development of neutrophilic asthma, exacerbating clinical symptoms and increasing the associated medical burden. In this work, arginine-grafted chitosan (CS-Arg) was ionically cross-linked with tris(2-carboxyethyl) phosphine (TCEP), and a highly-efficient antimicrobial agent, poly-ε-L-Lysine (ε-PLL), was incorporated to prepare ε-PLL/CS-Arg/TCEP (ECAT) composite nanogels. The results showed that ECAT nanogels exhibited highly effective inhibition against the proliferation of NTHi, Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). In addition, ECAT nanogels could effectively inhibit the formation of mucins aggregates in vitro, suggesting that the nanogel might have the potential to destroy mucin in respiratory disease. Furthermore, in the ovalbumin (OVA)/NTHi-induced Balb/c mice model of neutrophilic asthma, the number of neutrophils in the alveolar lavage fluid and the percentage of inflammatory cells in the blood were effectively reduced by exposure to tower nebulized administration of ECAT nanogels, and reversing airway hyperresponsiveness (AHR) and reducing inflammation in neutrophilic asthma mice. In conclusion, the construction of ECAT nanogels was a feasible anti-infective and anti-inflammatory therapeutic strategy, which demonstrated strong potential in the clinical treatment of neutrophilic asthma.

Asunto(s)

Antibacterianos , Asma , Quitosano , Escherichia coli , Ratones Endogámicos BALB C , Neutrófilos , Staphylococcus aureus , Animales , Staphylococcus aureus/efectos de los fármacos , Asma/tratamiento farmacológico , Antibacterianos/administración & dosificación , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Neutrófilos/efectos de los fármacos , Quitosano/administración & dosificación , Quitosano/química , Escherichia coli/efectos de los fármacos , Femenino , Haemophilus influenzae/efectos de los fármacos , Nanogeles/química , Ovalbúmina/administración & dosificación , Mucinas , Polilisina/química , Polilisina/administración & dosificación , Infecciones por Haemophilus/tratamiento farmacológico , Ratones , Polietileneimina/química , Polietileneimina/administración & dosificación , Geles

Asunto(s)

Antibacterianos , Infecciones por Haemophilus , Haemophilus influenzae , Pruebas de Sensibilidad Microbiana , Mutación , Quinolonas , Antibacterianos/farmacología , Humanos , Quinolonas/farmacología , Infecciones por Haemophilus/microbiología , Infecciones por Haemophilus/tratamiento farmacológico , Haemophilus influenzae/efectos de los fármacos , Haemophilus influenzae/genética , Farmacorresistencia Bacteriana/genética , Haemophilus/genética , Haemophilus/efectos de los fármacos

RESUMEN

The worldwide burden of disease of bacterial meningitis remains high, despite the decreasing incidence following introduction of routine vaccination campaigns.The aim of our study was to evaluate the epidemiological and bacteriological profile of paediatric bacterial meningitis (BM) in Tunisian children, during the period 2003-2019, following the implementation of Haemophilus influenzae type b (Hib) vaccine (April 2011) and before 10-valent pneumoccocal conjugate vaccine (PCV10) introduction to the childhood immunization program.All bacteriologically confirmed cases of BM admitted to children's hospital of Tunis were recorded (January 2003 to April 2019). Serogroups of Neisseria meningitidis (Nm) and serotypes of Streptococcus pneumoniae (Sp) and H. influenzae (Hi) and antibiotic resistance were determined using conventional and molecular methods.Among 388 cases, the most frequent species were Sp (51.3%), followed by Nm (27.5%) and Hi (16.8%). We observed a significant decrease in Hi BM rate during the conjugated Hib vaccine use period (P < 0.0001). The main pneumococcal serotypes were 14, 19F, 6B, 23F and 19A and the serotype coverage of PCV10, PCV13, PCV15 and PCV20 was 71.3 and 78.8%, 79.4 and 81.9% respectively. The most frequent Nm serogroup was B (83.1%). Most Hi strains were of serotype b (86.9%). High levels of resistance were found: Sp and Nm to penicillin (respectively 60.1 and 80%) and Hi to ampicillin (42.6%). All meningococcal and Hi isolates were susceptible to third-generation cephalosporins and 7.2% of pneumococcal strains had decreased susceptibility to these antibiotics.The Hib conjugate vaccine decreased the rate of BM. Sp dominated the aetiology of BM in children in Tunisia. Conjugate vaccines introducing decreases not only BM cases but also antimicrobial resistance.

Asunto(s)

Antibacterianos , Meningitis Bacterianas , Neisseria meningitidis , Vacunas Neumococicas , Streptococcus pneumoniae , Humanos , Túnez/epidemiología , Preescolar , Lactante , Streptococcus pneumoniae/clasificación , Streptococcus pneumoniae/aislamiento & purificación , Streptococcus pneumoniae/efectos de los fármacos , Meningitis Bacterianas/epidemiología , Meningitis Bacterianas/microbiología , Neisseria meningitidis/clasificación , Neisseria meningitidis/aislamiento & purificación , Neisseria meningitidis/efectos de los fármacos , Masculino , Femenino , Niño , Vacunas Neumococicas/administración & dosificación , Antibacterianos/farmacología , Haemophilus influenzae/aislamiento & purificación , Haemophilus influenzae/clasificación , Haemophilus influenzae/efectos de los fármacos , Vacunas contra Haemophilus/administración & dosificación , Serogrupo , Farmacorresistencia Bacteriana , Pruebas de Sensibilidad Microbiana , Recién Nacido , Adolescente , Cápsulas Bacterianas

RESUMEN

Antibiotic-resistant bacteria associated with LRTIs are frequently associated with inefficient treatment outcomes. Antibiotic-resistant Streptococcus pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa, and Staphylococcus aureus, infections are strongly associated with pulmonary exacerbations and require frequent hospital admissions, usually following failed management in the community. These bacteria are difficult to treat as they demonstrate multiple adaptational mechanisms including biofilm formation to resist antibiotic threats. Currently, many patients with the genetic disease cystic fibrosis (CF), non-CF bronchiectasis (NCFB) and chronic obstructive pulmonary disease (COPD) experience exacerbations of their lung disease and require high doses of systemically administered antibiotics to achieve meaningful clinical effects, but even with high systemic doses penetration of antibiotic into the site of infection within the lung is suboptimal. Pulmonary drug delivery technology that reliably deliver antibacterials directly into the infected cells of the lungs and penetrate bacterial biofilms to provide therapeutic doses with a greatly reduced risk of systemic adverse effects. Inhaled liposomal-packaged antibiotic with biofilm-dissolving drugs offer the opportunity for targeted, and highly effective antibacterial therapeutics in the lungs. Although the challenges with development of some inhaled antibiotics and their clinicals trials have been studied; however, only few inhaled products are available on market. This review addresses the current treatment challenges of antibiotic-resistant bacteria in the lung with some clinical outcomes and provides future directions with innovative ideas on new inhaled formulations and delivery technology that promise enhanced killing of antibiotic-resistant biofilm-dwelling bacteria.

Asunto(s)

Antibacterianos , Biopelículas , Sistemas de Liberación de Medicamentos , Infecciones del Sistema Respiratorio , Humanos , Biopelículas/efectos de los fármacos , Administración por Inhalación , Antibacterianos/administración & dosificación , Infecciones del Sistema Respiratorio/tratamiento farmacológico , Infecciones del Sistema Respiratorio/microbiología , Farmacorresistencia Bacteriana , Streptococcus pneumoniae/efectos de los fármacos , Liposomas , Bronquiectasia/tratamiento farmacológico , Bronquiectasia/microbiología , Haemophilus influenzae/efectos de los fármacos , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Pseudomonas aeruginosa/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Fibrosis Quística/microbiología , Fibrosis Quística/tratamiento farmacológico , Fibrosis Quística/complicaciones

RESUMEN

Transmission rates among children with conjunctivitis were low and antibiotic use was not associated with reduced transmission. Policies recommending exclusion from daycare and school for conjunctivitis should be scrutinized as they may not reduce transmission and may increase unnecessary antibiotic use.

Asunto(s)

Antibacterianos , Conjuntivitis Bacteriana , Infecciones por Haemophilus , Haemophilus influenzae , Humanos , Antibacterianos/uso terapéutico , Antibacterianos/administración & dosificación , Haemophilus influenzae/efectos de los fármacos , Infecciones por Haemophilus/tratamiento farmacológico , Preescolar , Conjuntivitis Bacteriana/tratamiento farmacológico , Conjuntivitis Bacteriana/microbiología , Lactante , Femenino , Masculino , Soluciones Oftálmicas/uso terapéutico , Conjuntivitis/tratamiento farmacológico , Conjuntivitis/microbiología , Niño , Administración Oftálmica , Resultado del Tratamiento

RESUMEN

BACKGROUND: Haemophilus influenzae is a frequently encountered pathogen responsible for respiratory tract infections in children. Following the detection of ceftriaxone-resistant H. influenzae at our institution, we aimed to investigate the resistance mechanisms of ceftriaxone in H. influenzae, with a particular focus on alterations in penicillin-binding protein 3 (PBP3) and ß-lactamase production. METHODS: Among H. influenzae isolates collected at Asan Medical Center Children's Hospital from March 2014 to April 2019, ceftriaxone-resistant strains by the disk-diffusion test were included. Ceftriaxone minimum inhibitory concentrations (MICs) were determined using the E-test according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. The presence of ß-lactamase was assessed through cefinase test and TEM-1/ROB-1 polymerase chain reaction (PCR). PBP3 alterations were explored via ftsI gene sequencing. RESULTS: Out of the 68 collected strains, 21 exhibited resistance to ceftriaxone in disk diffusion tests. Two strains were excluded due to failed subculture. Among 19 ceftriaxone-resistant H. influenzae isolates, eighteen were non-typeable H. influenzae, and twelve were positive for TEM-1 PCR. Isolates were classified into groups II (harboring only N526K, n = 3), III (N526K+S385T, n = 2), III+ (S385T+L389F+N526K, n = 11), and III-like+ (S385T+L389F+R517H, n = 3) according to the PBP3 alteration pattern. With a median ceftriaxone MIC of 0.190 mg/L (range, 0.008-0.750), the median ceftriaxone MIC was the highest in group III-like+ (0.250 mg/L), followed by groups III+ (0.190 mg/L), III (0.158 mg/L), and II (0.012 mg/L). All three strains belonging to group II, which did not harbor the S385T substitution, had ceftriaxone MICs of ≤ 0.125 mg/L. CONCLUSION: The emergence of ceftriaxone-resistant H. influenzae with ceftriaxone MIC values of up to 0.75 mg/L was observed even in children in South Korea, with most associated with S385T and L389F substitutions. The N526K mutation alone does not significantly impact ceftriaxone resistance. Further large-scale studies are essential to investigate changes in antibiotic resistance patterns and factors influencing antibiotic resistance in H. influenzae isolated from pediatric patients in Korea.

Asunto(s)

Antibacterianos , Ceftriaxona , Infecciones por Haemophilus , Haemophilus influenzae , Pruebas de Sensibilidad Microbiana , beta-Lactamasas , Ceftriaxona/farmacología , Haemophilus influenzae/efectos de los fármacos , Haemophilus influenzae/aislamiento & purificación , Haemophilus influenzae/genética , Humanos , Antibacterianos/farmacología , República de Corea , beta-Lactamasas/genética , beta-Lactamasas/metabolismo , Niño , Infecciones por Haemophilus/microbiología , Infecciones por Haemophilus/tratamiento farmacológico , Proteínas de Unión a las Penicilinas/genética , Preescolar , Farmacorresistencia Bacteriana , Lactante , Femenino , Masculino , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo

RESUMEN

OBJECTIVES: To investigate the prevalence of ampicillin resistance in Haemophilus influenzae and the diagnostic accuracy of the EUCAST recommended disc diffusion method to detect the increasingly prevalent ampicillin resistance due to the presence of PBP3 alterations based on mutations in the ftsI gene. METHODS: During a 6-month period all consecutive non-duplicate H. influenzae isolates were prospectively collected and stored. MICs of ampicillin were determined by broth microdilution (BMD). PCR was performed to detect mutations in the ftsI gene. Results of routine disc diffusion susceptibility testing, including the penicillin screening test in accordance with the current EUCAST methodology, as well as additional Etest results, were compared to the BMD as the reference method. RESULTS: In 102 isolates, the prevalence of ampicillin resistance was 28% (29/102) by BMD. There was a good correlation between MICs of ampicillin and the presence of a ß-lactamase and/or an ftsI gene mutation. The prevalence of ampicillin resistance was overestimated using the EUCAST method (33% (34/102)) and underestimated when an additional Etest was used (24% (24/102)) (not significant). The sensitivity and specificity of the EUCAST methodology for the detection of ampicillin resistance were 97% ((28/29); 95% CI, 82-100%) and 92% ((67/73); 95% CI, 83-97%), respectively. CONCLUSIONS: The prevalence of ampicillin resistance was 28%, as determined by BMD. Although the overall diagnostic accuracy of the EUCAST ampicillin disc diffusion was high, misclassification of ampicillin susceptibility may still occur.

Asunto(s)

Resistencia a la Ampicilina , Ampicilina , Infecciones por Haemophilus , Haemophilus influenzae , Pruebas de Sensibilidad Microbiana , Mutación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Adulto Joven , Ampicilina/farmacología , Resistencia a la Ampicilina/genética , Antibacterianos/farmacología , Pruebas Antimicrobianas de Difusión por Disco/métodos , Infecciones por Haemophilus/microbiología , Haemophilus influenzae/efectos de los fármacos , Haemophilus influenzae/genética , Pruebas de Sensibilidad Microbiana/métodos , Proteínas de Unión a las Penicilinas/genética , Prevalencia , Estudios Prospectivos

RESUMEN

With the widespread introduction of the Hib conjugate vaccine, Nontypeable Haemophilus influenzae (NTHi) has emerged as the predominant strain globally. NTHi presents a significant challenge as a causative agent of chronic clinical infections due to its high rates of drug resistance and biofilm formation. While current research on NTHi biofilms in children has primarily focused on upper respiratory diseases, investigations into lower respiratory sources remain limited. In this study, we collected 54 clinical strains of lower respiratory tract origin from children. Molecular information and drug resistance features were obtained through whole gene sequencing and the disk diffusion method, respectively. Additionally, an in vitro biofilm model was established. All clinical strains were identified as NTHi and demonstrated the ability to form biofilms in vitro. Based on scanning electron microscopy and crystal violet staining, the strains were categorized into weak and strong biofilm-forming groups. We explored the correlation between biofilm formation ability and drug resistance patterns, as well as clinical characteristics. Stronger biofilm formation was associated with a longer cough duration and a higher proportion of abnormal lung imaging findings. Frequent intake of ß-lactam antibiotics might be associated with strong biofilm formation. While a complementary relationship between biofilm-forming capacity and drug resistance may exist, further comprehensive studies are warranted. This study confirms the in vitro biofilm formation of clinical NTHi strains and establishes correlations with clinical characteristics, offering valuable insights for combating NTHi infections.

Asunto(s)

Antibacterianos , Biopelículas , Infecciones por Haemophilus , Haemophilus influenzae , Biopelículas/crecimiento & desarrollo , Humanos , Infecciones por Haemophilus/microbiología , Haemophilus influenzae/fisiología , Haemophilus influenzae/aislamiento & purificación , Haemophilus influenzae/genética , Haemophilus influenzae/efectos de los fármacos , Haemophilus influenzae/clasificación , Antibacterianos/farmacología , Preescolar , Femenino , Masculino , Niño , Lactante , Pruebas de Sensibilidad Microbiana , Infecciones del Sistema Respiratorio/microbiología , Infecciones del Sistema Respiratorio/virología , Microscopía Electrónica de Rastreo , Farmacorresistencia Bacteriana , Sistema Respiratorio/microbiología , Sistema Respiratorio/virología

RESUMEN

OBJECTIVES: 17ß-estradiol (E2) is a steroidal hormone with immunomodulatory functions that play a role in infectious and inflammatory diseases. E2 was recently identified as the leading upstream regulator of differentially expressed genes in a comparative RNA sequencing study of pediatric patients with otitis media (OM) versus OM-free counterparts and may therefore play a role in the inflammatory response to bacterial otopathogens during pediatric OM. This study examined the effect of E2 on bacterial-induced inflammatory cytokine expression in an in vitro pediatric OM model. METHODS: An immortalized middle ear (ME) epithelial cell line, ROM-SV40, was developed from a pediatric recurrent OM patient. The culture was exposed to E2 at physiological levels for 1-48 h prior to 6 h-stimulation with nontypeable Haemophilus influenzae (NTHi) whole cell lysate. TNFA, IL1B, IL6, and IL8 were assayed by qPCR and ELISA. RESULTS: E2 pretreatment (24 h) abrogated NTHi induction of IL6; a longer pretreatment (1-10 nM, 48 h) abrogated IL1B induction (p < 0.05). E2 pretreatment (5 nM, 48 h) abrogated NTHi-induced IL8 secretion (p = 0.017). CONCLUSION: E2 pretreatment partially rescued NTHi-induced cytokine production by ME epithelia. These data support a role for E2 in moderating the excessive inflammatory response to middle ear infection that contributes to OM pathophysiology. LEVELS OF EVIDENCE: NA Laryngoscope, 134:3815-3819, 2024.

Asunto(s)

Citocinas , Oído Medio , Estradiol , Haemophilus influenzae , Otitis Media , Humanos , Haemophilus influenzae/efectos de los fármacos , Estradiol/farmacología , Otitis Media/microbiología , Otitis Media/inmunología , Otitis Media/tratamiento farmacológico , Oído Medio/microbiología , Oído Medio/efectos de los fármacos , Citocinas/metabolismo , Infecciones por Haemophilus/inmunología , Infecciones por Haemophilus/tratamiento farmacológico , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Niño , Línea Celular , Inflamación

RESUMEN

In 2013, Uganda introduced the PCV10 pneumococcal vaccine and it is given to children at 6, 10 and 14 weeks after birth. Carriage prevalence studies post PCV10-introduction are necessary for monitoring the impact of vaccination and trends in antibiotic resistance. Here, we studied carriage/antibiotic resistance of Streptococcus pneumoniae (pneumococcus), Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus isolated from 194 children at the Mulago Assessment Centre clinic in Kampala-Uganda, 5 years post-PCV10 introduction. Almost all the children were vaccinated with PCV10 (98.5%, 191/194). The overall carriage prevalence (any species) was 62% (120/194), and it was associated with a history of antibiotics use (p=0.0159) and having respiratory symptoms (p=0.0003). The pneumococcus, H. influenzae, M. catarrhalis, and S. aureus carriage prevalence was 46% (90/194), 21% (40/194), 7% (14/194), and 6% (12/194), respectively. Species co-carriage occurred in 32 children (17%, 32/194), predominantly multidrug resistant pneumococcus + H. influenzae (23 children). Furthermore, pneumococci were highly resistant to cotrimoxazole (100%), erythromycin (76%), and tetracycline (52%), 42% being multidrug-resistant. Overall, we note an increase in antibiotic resistance post-PCV10 introduction, and microbial shifts i.e., a decrease in pneumococcus, M. catarrhalis and S. aureus carriage and an increase in H. influenzae carriage suggesting vaccine-associated perturbation of the respiratory ecology.

Asunto(s)

Antibacterianos , Portador Sano , Haemophilus influenzae , Pruebas de Sensibilidad Microbiana , Moraxella catarrhalis , Nasofaringe , Vacunas Neumococicas , Staphylococcus aureus , Streptococcus pneumoniae , Humanos , Streptococcus pneumoniae/efectos de los fármacos , Streptococcus pneumoniae/aislamiento & purificación , Uganda/epidemiología , Estudios Transversales , Haemophilus influenzae/efectos de los fármacos , Haemophilus influenzae/aislamiento & purificación , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/aislamiento & purificación , Femenino , Moraxella catarrhalis/aislamiento & purificación , Moraxella catarrhalis/efectos de los fármacos , Nasofaringe/microbiología , Masculino , Preescolar , Portador Sano/epidemiología , Portador Sano/microbiología , Antibacterianos/farmacología , Vacunas Neumococicas/administración & dosificación , Lactante , Prevalencia , Niño , Farmacorresistencia Bacteriana

RESUMEN

Antibiotics are important for the treatment and prevention of invasive Haemophilus influenzae disease. Reduced susceptibility to clinically relevant drugs, except ampicillin, has been uncommon in the United States. Susceptibility of 700 invasive H. influenzae isolates, collected through population-based surveillance during 2016, was assessed for 15 antibiotics using broth microdilution, according to the CLSI guidelines; a subset of 104 isolates were also assessed for rifampin susceptibility using Etest. Genomes were sequenced to identify genes and mutations known to be associated with reduced susceptibility to clinically relevant drugs. A total of 508 (72.6%) had reduced susceptibility to at least one antibiotic and more than half of the isolates exhibited reduced susceptibility to only one (33.6%) or two (21.6%) antibiotic classes. All tested isolates were susceptible to rifampin, a chemoprophylaxis agent, and <1% (n = 3) of isolates had reduced susceptibility to third generation cephalosporins, which are recommended for invasive disease treatment. In contrast, ampicillin resistance was more common (28.1%) and predominantly associated with the detection of a ß-lactamase gene; 26.2% of isolates in the collection contained either a TEM-1 or ROB-1 ß-lactamase gene, including 88.8% of ampicillin-resistant isolates. ß-lactamase negative ampicillin-resistant (BLNAR) isolates were less common and associated with ftsI mutations; resistance to amoxicillin-clavulanate was detected in <2% (n = 13) of isolates. The proportion of reduced susceptibility observed was higher among nontypeable H. influenzae and serotype e than other serotypes. US invasive H. influenzae isolates remain predominantly susceptible to clinically relevant antibiotics except ampicillin, and BLNAR isolates remain uncommon. IMPORTANCE Antibiotics play an important role for the treatment and prevention of invasive Haemophilus influenzae disease. Antimicrobial resistance survey of invasive H. influenzae isolates collected in 2016 showed that the US H. influenzae population remained susceptible to clinically relevant antibiotics, except for ampicillin. Detection of approximately a quarter ampicillin-resistant and ß-lactamase containing strains demonstrates that resistance mechanisms can be acquired and sustained within the H. influenzae population, highlighting the continued importance of antimicrobial resistance surveillance for H. influenzae to monitor susceptibility trends and mechanisms of resistance.

Asunto(s)

Antibacterianos , Farmacorresistencia Bacteriana , Haemophilus influenzae , Ampicilina/farmacología , Ampicilina/uso terapéutico , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Infecciones por Haemophilus/tratamiento farmacológico , Infecciones por Haemophilus/epidemiología , Haemophilus influenzae/efectos de los fármacos , Haemophilus influenzae/genética , Humanos , Pruebas de Sensibilidad Microbiana , Rifampin/farmacología , Rifampin/uso terapéutico , Estados Unidos/epidemiología , beta-Lactamasas/genética

RESUMEN

BACKGROUND: Since the introduction of Haemophilus influenzae type b vaccines, invasive disease due to Haemophilus influenzae serotype a (Hia) has been reported with increasing frequency. METHODS: This study is based on hospital-based surveillance for Hia meningitis over a 5-year period. RESULTS: Thirty-five patients with H. influenzae meningitis were hospitalized and 12 were serotype a. Hia was detected in blood and cerebrospinal fluid by culture or reverse transcription polymerase chain reaction. Patients' median age was 10 months, 7 (58%) boys and 5 (41%) girls. Ten (83%) children had received at least 1 vaccine dose against Haemophilus influenzae type b. All patients were treated with ceftriaxone for a median period of 11 days. The main complications described were empyema in 5 (41%) and seizures in 3 (25%) patients. Two (16.6%) patients died due to cerebral damage and shock. CONCLUSIONS: Invasive disease due to Hia affecting young children accounts for considerable morbidity and mortality.

Asunto(s)

Vacunas contra Haemophilus/efectos adversos , Haemophilus influenzae , Meningitis por Haemophilus/microbiología , Antibacterianos/farmacología , Brasil , Niño , Preescolar , Femenino , Haemophilus influenzae/clasificación , Haemophilus influenzae/efectos de los fármacos , Haemophilus influenzae/aislamiento & purificación , Humanos , Lactante , Masculino , Pruebas de Sensibilidad Microbiana , Serotipificación

RESUMEN

Tentacle-like polymers decorated with several copies of peptide antigens can be interesting tools for increasing the ability to capture circulating antibodies in patient sera, using cooperative effects for stronger avidity. We previously showed that antibodies from multiple sclerosis (MS) patient sera preferentially recognize hyperglucosylated adhesin protein HMW1ct of non-typeable Haemophilus influenzae (NTHi). We selected the C-terminal HMW1ct(1347-1354) minimal epitope and prepared the diglucosylated analogue Ac-KAN(Glc)VTLN(Glc)TTG-K(N3 )-NH2 to graft a 40 kDa dextran scaffold modified with glycidyl-propargyl moieties to perform a copper catalyzed alkyne-azide coupling reaction (CuAAC). Quantitative NMR measurements allowed the characterization of the peptide loading (19.5 %) on the multivalent dextran conjugate. This novel polymeric structure displayed optimal capturing properties of both IgG and, more interestingly, IgM antibodies in MS sera. Specific antibodies from a representative MS serum, were successfully depleted using a Sepharose resin bearing the new glucosylated multivalent conjugate, as confirmed by ELISA. These results may offer a promising proof-of-concept for the selective purification of high affinity autoantibodies from sera of autoimmune patients, in general, and of specific high affinity antibodies against a minimally glcosylated epitope Asn(Glc) from sera of multiple sclerosis (MS) patients, in particular.

Asunto(s)

Adhesinas Bacterianas/efectos de los fármacos , Antibacterianos/farmacología , Autoanticuerpos/farmacología , Dextranos/farmacología , Haemophilus influenzae/efectos de los fármacos , Péptidos/farmacología , Antibacterianos/química , Autoanticuerpos/química , Dextranos/química , Glicosilación , Humanos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Péptidos/química