RESUMO

BACKGROUND: Analyze the incidence, risk factors, and fatality rates of bloodstream infections by Gram-negative bacteria (GNB-BSIs) in a Neonatal Intensive Care Unit. METHODS: This study employs a retrospective cohort design utilizing records of neonates admitted to the Neonatal Intensive Care Unit between January 2015 and June 2022. RESULTS: Among 1,495 neonates, 5.2% developed GNB-BSIs. The average incidence of infection per 1,000 patient-days was 2.9. Primary risk factors for infection that included preceeding carbapenem use were significant risk factors (odds ratio=514.4; P < .01) and fourth-generation cephalosporins (odds ratio=66; P < .01). Among the 85 GNB, 75.3% were fermenters, and 24.7% were non-fermenters. Of the isolates, 14.1% produced extended-spectrum beta-lactamase, and 2.3% carbapenem-resistant. Infection correlated with prolonged hospital stays (10-39days) and increased mortality (10%-29.9%). CONCLUSIONS: The high incidence of GNB-BSIs was exacerbated by the preceeding use of broad-spectrum antimicrobials, increasing the presence of multidrug-resistant isolates and fatality rates. These findings emphasize the importance of active surveillance.

RESUMO

The emergence and propagation of bacteria resistant to antimicrobial drugs is a serious public health threat worldwide. The current antibacterial arsenal is becoming obsolete and the pace of drug development is decreasing, highlighting the importance of investment in alternative approaches to treat or prevent infections caused by antimicrobial-resistant bacteria. A significant mechanism of antimicrobial resistance employed by Gram-negative bacteria is the overexpression of efflux pumps that can extrude several compounds from the bacteria, including antimicrobials. The overexpression of efflux pump proteins has been detected in several multidrug resistant (MDR) Gram-negative bacteria, drawing attention to these proteins as potential targets against these pathogens. This review will focus on the role of outer membrane proteins (OMPs) from efflux pumps as potential vaccine candidates against clinically relevant MDR Gram-negative bacteria, discussing advantages and pitfalls. Additionally, we will explore the relevance of efflux pump OMP diversity and the possible impact of vaccination on microbiota.

RESUMO

Solid organ transplant (SOT) recipients are particularly susceptible to infections caused by multidrug-resistant organisms (MDRO) and are often the first to be affected by an emerging resistant pathogen. Unfortunately, their prevalence and impact on morbidity and mortality according to the type of graft is not systematically reported from high-as well as from low and middle-income countries (HIC and LMIC). Thus, epidemiology on MDRO in SOT recipients could be subjected to reporting bias. In addition, screening practices and diagnostic resources may vary between countries, as well as the availability of new drugs. In this review, we aimed to depict the burden of main Gram-negative MDRO in SOT patients across HIC and LMIC and to provide an overview of current diagnostic and therapeutic resources.

Assuntos

Farmacorresistência Bacteriana Múltipla , Transplante de Órgãos , Humanos , Transplante de Órgãos/efeitos adversos , Transplantados , Antibacterianos/uso terapêutico , Prevalência , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/epidemiologia , Países em Desenvolvimento

RESUMO

The natural antimicrobial properties of essential oils (EOs) have contributed to the battle against multidrug-resistant microorganisms by providing new ways to develop more effective antibiotic agents. In this study, we investigated the chemical composition of Ocotea diospyrifolia essential oil (OdOE) and its antimicrobial properties combined with amikacin (AMK). Through gas chromatography-mass spectrometry (GCMS) analysis, the primary constituents of OdOE were identified as α-bisabolol (45.8 %), ß-bisabolene (9.4 %), γ-elemene (7.6 %), (Z)- ß-farnesene (5.2 %), spathulenol (3.5 %), (Z)-caryophyllene (3.3 %), and (E)-caryophyllene (3.1 %). In vitro assessments showed that the combined administration of OdOE and AMK exerted a synergistic antibacterial effect on the multidrug-resistant K. pneumoniae strain. This synergistic effect demonstrated bacteriostatic action. OdEO combined with amikacin showed protein extravasation within 2 h of treatment, leading to bacterial death, which was determined by a reduction in viable cell count. The effective concentrations showed hemocompatibility. In vivo assessments using Caenorhabditis elegans as a model showed the survival of 85 % of infected nematodes. Therefore, the combination OdEO combined with amikacin exhibited antimicrobial activity against a multidrug-resistant K. pneumoniae strain. Thus, OdOE is a promising agent that may be considered for development of antimicrobial treatment.

Assuntos

Amicacina , Antibacterianos , Farmacorresistência Bacteriana Múltipla , Sinergismo Farmacológico , Klebsiella pneumoniae , Testes de Sensibilidade Microbiana , Óleos Voláteis , Amicacina/farmacologia , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Animais , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Antibacterianos/farmacologia , Klebsiella pneumoniae/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Caenorhabditis elegans/efeitos dos fármacos , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Sesquiterpenos Monocíclicos/farmacologia , Sesquiterpenos Policíclicos/farmacologia , Sesquiterpenos Policíclicos/química , Sesquiterpenos/farmacologia

RESUMO

OBJECTIVE: Despite the increasing reports of blaNDM in Enterobacterales in Brazil, comprehensive whole genome sequencing (WGS) data remain scarce. To address this knowledge gap, our study focuses on the characterization of the genome of an New Delhi Metallo-ß-lactamase (NDM)-1-producing Klebsiella quasipneumoniae subsp. quasipneumoniae (KQPN) clinical strain isolated in Brazil. METHODS: The antimicrobial susceptibility profile of the A-73.113 strain was performed by agar dilution or broth microdilution following the Brazilian Antimicrobial Susceptibility Testing Committee/European Committee on Antimicrobial Susceptibility Testing recommendations. WGS was performed using the Illumina® NextSeq platform and the generated reads were assembled using the SPAdes software. The sequences obtained were submitted to the bioinformatics pipelines to determine the sequence type, resistome, plasmidome, and virulome. RESULTS: The A-73.113 strain was identified as KQPN and was susceptible to polymyxins (MICs, ≤0.25 µg/mL), tigecycline (MIC, 0.5 µg/mL), ciprofloxacin (MIC, 0.5 µg/mL), and levofloxacin (MIC, 1 µg/mL). WGS analysis revealed the presence of genes conferring resistance to ß-lactams (blaNDM-1, blaCTX-M-15, blaOXA-9, blaOKP-A-5, blaTEM-1), aminoglycosides [aph(3')-VI, aadA1, aac(6')-Ib], and fluoroquinolones (oqxAB, qnrS1, aac(6')-Ib-cr]. Additionally, the presence of the plasmid replicons Col(pHAD28), IncFIA(HI1), IncFIB(K) (pCAV1099-114), IncFIB(pQil), and IncFII(K), as well as virulence-encoding genes fimABCDEFGHIK (type 1 fimbria), pilW (type IV pili), iutA (aerobactin), entABCDEFS/fepABCDG/fes (Ent siderophores), iroE (salmochelin), and allABCDRS (allantoin utilization) was verified. Furthermore, we found that the A-73.113 strain belongs to ST1040. CONCLUSIONS: Here we report the genomic characteristics of an NDM-1-producing KQPN ST1040 strain isolated from blood cultures in Brazil. These data will enhance our comprehension of how this species contributes to the acquisition and dissemination of blaNDM-1 in Brazilian nosocomial settings.

Assuntos

Antibacterianos , Genoma Bacteriano , Infecções por Klebsiella , Klebsiella , Testes de Sensibilidade Microbiana , Plasmídeos , Sequenciamento Completo do Genoma , beta-Lactamases , beta-Lactamases/genética , Humanos , Klebsiella/genética , Klebsiella/efeitos dos fármacos , Klebsiella/isolamento & purificação , Klebsiella/enzimologia , Antibacterianos/farmacologia , Infecções por Klebsiella/microbiologia , Plasmídeos/genética , Brasil , Farmacorresistência Bacteriana Múltipla/genética

RESUMO

Introduction: Nosocomial infectious ventriculitis caused by multidrug-resistant (MDR) Gram-negative bacilli associated with external ventricular drainage (EVD) placement poses a significant mortality burden and hospital costs. Objectives: This study aims to analyze the characteristics, ventriculitis evolution, treatment, and outcomes of patients with ventriculitis due to MDR Gram-negative bacilli associated with EVD placement. Methods: A retrospective cohort study focusing on patients with nosocomial infection caused by MDR Gram-negative bacilli while on EVD was conducted from 2019 to 2022. Medical, laboratory, and microbiological records were collected. The antibiotic resistance of the Gram-negative bacilli isolated in the cerebrospinal fluid (CSF) of patients was analyzed. The risk factors were identified using univariate risk models and were analyzed using survival curves (Cox regression). An adjusted Cox proportional hazards model was also constructed. Results: Among 530 patients with suspected EVD-associated ventriculitis, 64 patients with isolation of Gram-negative bacilli in CSF were included. The estimated mortality was 78.12%. Hemorrhages (intracranial, subarachnoid, and intraventricular) were observed in 69.8% of patients. Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa were the most frequently isolated bacilli. In the univariate analysis, significant risk factors for mortality included arterial hypertension, a Glasgow Coma Scale (GCS) score of ≤ 8, invasive mechanical ventilation (IMV) upon hospital admission and during hospitalization, septic shock, and ineffective treatment. The adjusted Cox proportional hazards model revealed that septic shock (HR = 3.3, 95% CI = 1.5-7.2; p = 0.003) and ineffective treatment (HR = 3.2, 1.6-6.5, 0.001) were significant predictors. A high resistance to carbapenems was found for A. baumannii (91.3%) and P. aeruginosa (80.0%). Low resistance to colistin was found for A. baumannii (4.8%) and P. aeruginosa (12.5%). Conclusion: Ineffective treatment was an independent hazard factor for death in patients with ventriculitis caused by MDR Gram-negative bacilli associated with EVD.

RESUMO

This research communication addresses the hypothesis that double premilking teat disinfection (DD) is more effective in reducing soiling and bacterial count on the cows' teat skin and milkers' gloves than conventional disinfection (CONV). The design was a 3 × 3 Latin square (three groups of cows and three treatments) with conventional teat disinfection (CONV, lactic acid application after forestripping), double teat disinfection using the same disinfectant (DD1D, lactic acid application before and after forestripping), and double teat disinfection using two different disinfectants (DD2D, application of lactic acid before and chlorine-based disinfectant after forestripping). All groups were assigned for six days for each treatment, and the evaluations and samples were collected on the last day, before and after treatment. We evaluated the teat cleanliness score (TCS), count of Gram-negative bacteria (coliforms and noncoliforms), Staphylococcus spp., Streptococcus spp., and total bacterial count (TBC) on the cows' teats and TBC on the milkers' gloves. TCS after premilking was lower in DD than CONV treatment. The reduction of Staphylococcus spp. count was greater in the DD treatment and tended to be higher in the DD2D. The TBC reduction on the cows' teats was greater in the DD treatments. The TBC on the milkers' gloves was lower for DD before and after premilking. In conclusion, DD can be an alternative for reducing some bacterial populations on cow teats and preventing the transmission of microorganisms between cows via the milkers' hands.

RESUMO

Aeromonas spp. are frequently encountered in aquatic environments, with Aeromonas veronii emerging as an opportunistic pathogen causing a range of diseases in both humans and animals. Recent reports have raised public health concerns due to the emergence of multidrug-resistant Aeromonas spp. This is particularly noteworthy as these species have demonstrated the ability to acquire and transmit antimicrobial resistance genes (ARGs). In this study, we report the genomic and phenotypic characteristics of the A. veronii TR112 strain, which harbors a novel variant of the Vietnamese Extended-spectrum ß-lactamase-encoding gene, blaVEB-28, and two mcr variants recovered from an urban river located in the Metropolitan Region of São Paulo, Brazil. A. veronii TR112 strain exhibited high minimum inhibitory concentrations (MICs) for ceftazidime (64 µg/mL), polymyxin (8 µg/mL), and ciprofloxacin (64 µg/mL). Furthermore, the TR112 strain demonstrated adherence to HeLa and Caco-2 cells within 3 h, cytotoxicity to HeLa cells after 24 h of interaction, and high mortality rates to the Galleria mellonella model. Genomic analysis showed that the TR112 strain belongs to ST257 and presented a range of ARGs conferring resistance to ß-lactams (blaVEB-28, blaCphA3, blaOXA-912) and polymyxins (mcr-3 and mcr-3.6). Additionally, we identified a diversity of virulence factor-encoding genes, including those encoding mannose-sensitive hemagglutinin (Msh) pilus, polar flagella, type IV pili, type II secretion system (T2SS), aerolysin (AerA), cytotoxic enterotoxin (Act), hemolysin (HlyA), hemolysin III (HlyIII), thermostable hemolysin (TH), and capsular polysaccharide (CPS). In conclusion, our findings suggest that A. veronii may serve as an environmental reservoir for ARGs and virulence factors, highlighting its importance as a potential pathogen in public health.

Assuntos

Aeromonas veronii , Antibacterianos , Testes de Sensibilidade Microbiana , Rios , beta-Lactamases , beta-Lactamases/genética , beta-Lactamases/metabolismo , Humanos , Antibacterianos/farmacologia , Rios/microbiologia , Aeromonas veronii/genética , Aeromonas veronii/isolamento & purificação , Aeromonas veronii/efeitos dos fármacos , Brasil , Células HeLa , Células CACO-2 , Animais , Farmacorresistência Bacteriana Múltipla/genética

RESUMO

INTRODUCTION: Carbapenem-resistant gram-negative bacilli are a worldwide concern because of high morbidity and mortality rates. Additionally, the increasing prevalence of these bacteria is dangerous. To investigate the extent of antimicrobial resistance and prioritize the utility of novel drugs, we evaluated the molecular characteristics and antimicrobial susceptibility profiles of carbapenem-resistant Enterobacterales, Pseudomonas aeruginosa and Acinetobacter baumannii in Ecuador in 2022. METHODS: Ninety-five clinical isolates of carbapenem non-susceptible gram-negative bacilli were collected from six hospitals in Ecuador. Carbapenem resistance was confirmed with meropenem disk diffusion assays following Clinical Laboratory Standard Institute guidelines. Carbapenemase production was tested using a modified carbapenemase inactivation method. Antimicrobial susceptibility was tested with a disk diffusion assay, the Vitek 2 System, and gradient diffusion strips. Broth microdilution assays were used to assess colistin susceptibility. All the isolates were screened for the blaKPC, blaNDM, blaOXA-48, blaVIM and blaIMP genes. In addition, A. baumannii isolates were screened for the blaOXA-23, blaOXA-58 and blaOXA-24/40 genes. RESULTS: Carbapenemase production was observed in 96.84% of the isolates. The blaKPC, blaNDM and blaOXA-48 genes were detected in Enterobacterales, with blaKPC being predominant. The blaVIM gene was detected in P. aeruginosa, and blaOXA-24/40 predominated in A. baumannii. Most of the isolates showed co-resistance to aminoglycosides, fluoroquinolones, and trimethoprim/sulfamethoxazole. Both ceftazidime/avibactam and meropenem/vaborbactam were active against carbapenem-resistant gram-negative bacilli that produce serin-carbapenemases. CONCLUSION: The epidemiology of carbapenem resistance in Ecuador is dominated by carbapenemase-producing K. pneumoniae harbouring blaKPC. Extensively drug resistant (XDR) P. aeruginosa and A. baumannii were identified, and their identification revealed the urgent need to implement strategies to reduce the dissemination of these strains.

Assuntos

Carbapenêmicos , beta-Lactamases , Humanos , Carbapenêmicos/farmacologia , Meropeném , Epidemiologia Molecular , Equador/epidemiologia , Testes de Sensibilidade Microbiana , beta-Lactamases/genética , Proteínas de Bactérias/genética , Antibacterianos/farmacologia , Bactérias Gram-Negativas/genética , Klebsiella pneumoniae/genética , Pseudomonas aeruginosa/genética

RESUMO

We assessed 160 patients who received imipenem/cilastatin/relebactam for ≥2 days. At treatment initiation, the median Charlson Comorbidity Index was 5, 45% were in the intensive care unit, and 19% required vasopressor support. The in-hospital mortality rate was 24%. These data advance our understanding of real-world indications and outcomes of imipenem/cilastatin/relebactam use.

Assuntos

Antibacterianos , Compostos Azabicíclicos , Cilastatina , Imipenem , Humanos , Masculino , Antibacterianos/farmacologia , Feminino , Imipenem/farmacologia , Pessoa de Meia-Idade , Idoso , Cilastatina/farmacologia , Cilastatina/administração & dosagem , Cilastatina/uso terapêutico , Estados Unidos , Compostos Azabicíclicos/farmacologia , Combinação Imipenem e Cilastatina/administração & dosagem , Mortalidade Hospitalar , Estudos Retrospectivos , Unidades de Terapia Intensiva , Idoso de 80 Anos ou mais , Resultado do Tratamento , Adulto

RESUMO

Background: Febrile neutropenia is a life-threatening condition commonly observed in patients with hematologic malignancies. The aim of this article is to provide updated knowledge about bloodstream infections in febrile neutropenia episodes within the Andean region of Latin America. Method: This retrospective study was based in 6 hospitals in Chile, Ecuador, and Peru and included adult patients with acute leukemia or lymphoma and febrile neutropenia between January 2019 and December 2020. Results: Of the 416 febrile neutropenia episodes, 38.7% had a bloodstream infection, 86% of which were caused by gram-negative rods, with Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa being the most frequently identified bacteria. K pneumoniae isolates were more frequently resistant than E coli to cefotaxime (65% vs 39.6%), piperacillin-tazobactam (56.7% vs 27.1%), and imipenem (35% vs 2.1%) and were more frequently multidrug resistant (61.7% vs 12.5%). Among P aeruginosa, 26.7% were resistant to ceftazidime, piperacillin-tazobactam, and imipenem, and 23.3% were multidrug resistant. Overall 30-day mortality was 19.8%, being higher with vs without a bloodstream infection (26.7% vs 15.3%, P = .005). Fever duration was also significantly longer, as well as periods of neutropenia and length of hospital stay for patients with bloodstream infection. Additionally, the 30-day mortality rate was higher for episodes with inappropriate vs appropriate empirical antibiotic therapy (41.2% vs 26.6%, P = .139). Conclusions: Considering the high rates of bacteria-resistant infection and 30-day mortality, it is imperative to establish strategies that reduce the frequency of bloodstream infections, increasing early identification of patients at higher risks of multidrug bacteria resistance, and updating existing empirical antibiotic recommendations.

RESUMO

BACKGROUND: Urinary tract infections (UTIs) can lead to neonatal complications like sepsis, worsened by empirical treatment, contributing to antimicrobial resistance (AMR). This study examined the incidence, etiology, risk factors, and antimicrobial susceptibility of uropathogens in a Neonatal Intensive Care Unit (NICU) in Brazil. METHODS: Medical records of neonates hospitalized in the NICU from January 2015 to June 2022 were retrospectively analyzed through the National Healthcare Safety Network system. RESULTS: Among 1,474 neonates, 3.9% developed UTI, with an alarming 24-fold increase in incidence from 2015 to 2021. Genitourinary complications (odds ratio = 4.8) were a major risk factor. Of the 71 uropathogens, 74.6% were Gram-negative bacteria (GNB), 21.2% Gram-positive bacteria (GPB), and 4.2% Candida albicans. AMR was notable, with 13.3% of GPB and 20.7% of GNB exhibiting multidrug-resistant (MDR), while 6.6% of GPB and 1.9% of GNB showed extensive drug-resistant (XDR). UTI was associated with prolonged hospitalization (16-59 days). In 57 neonates with UTI, 40.3% had bloodstream infections, elevating the risk of death (odds ratio = 1.8). CONCLUSIONS: The study underscores the urgency of implementing infection prevention and control measures in the NICU to curb rising UTI incidences, combat AMR, and mitigate severe complications in critically ill neonates.

Assuntos

Unidades de Terapia Intensiva Neonatal , Infecções Urinárias , Humanos , Infecções Urinárias/epidemiologia , Infecções Urinárias/microbiologia , Brasil/epidemiologia , Recém-Nascido , Unidades de Terapia Intensiva Neonatal/estatística & dados numéricos , Estudos Retrospectivos , Feminino , Masculino , Incidência , Fatores de Risco , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/isolamento & purificação , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia

RESUMO

OBJECTIVES: Ceftazidime-avibactam (CAZ-AVI) is an option for infections caused by MDR gram-negative bacilli. In this study, we aimed to analyze the in vitro antimicrobial activity of CAZ-AVI and other antimicrobial agents against gram-negative bacilli that were collected in Colombia between 2019 and 2021 from patients with bacteremia and skin and soft-tissue infections (SSTIs). METHODS: A total of 600 Enterobacterales and 259 P. aeruginosa strains were analyzed. The phenotypic resistance of isolates, particularly non-susceptibility to meropenem, multidrug-resistant (MDR) isolates, and difficult-to-treat (DTR) P. aeruginosa, was evaluated according to CLSI breakpoints. RESULTS: Enterobacterales had the most susceptibility to CAZ-AVI (96.5 %) and tigecycline (95 %). Tigecycline and CAZ-AVI were the antimicrobial agents with the most in vitro activity against carbapenem-resistant Enterobacterales (CRE). CAZ-AVI was the antimicrobial treatment with the most activity against P. aeruginosa. CONCLUSIONS: Tigecycline and CAZ-AVI were the antimicrobial agents with the most activity against CRE and MDR Enterobacterales. For P. aeruginosa, CAZ-AVI was the antimicrobial treatment with the most in vitro activity.

Assuntos

Antibacterianos , Compostos Azabicíclicos , Bacteriemia , Ceftazidima , Combinação de Medicamentos , Bactérias Gram-Negativas , Testes de Sensibilidade Microbiana , Infecções dos Tecidos Moles , Tigeciclina , Humanos , Ceftazidima/farmacologia , Infecções dos Tecidos Moles/microbiologia , Infecções dos Tecidos Moles/tratamento farmacológico , Colômbia , Compostos Azabicíclicos/farmacologia , Antibacterianos/farmacologia , Bacteriemia/microbiologia , Bacteriemia/tratamento farmacológico , Bactérias Gram-Negativas/efeitos dos fármacos , Tigeciclina/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Enterobacteriaceae/efeitos dos fármacos , Dermatopatias Bacterianas/microbiologia , Dermatopatias Bacterianas/tratamento farmacológico

RESUMO

The bacterial envelope is an essential compartment involved in metabolism and metabolites transport, virulence, and stress defense. Its roles become more evident when homeostasis is challenged during host-pathogen interactions. In particular, the presence of free radical groups and excess copper in the periplasm causes noxious reactions, such as sulfhydryl group oxidation leading to enzymatic inactivation and protein denaturation. In response to this, canonical and accessory oxidoreductase systems are induced, performing quality control of thiol groups, and therefore contributing to restoring homeostasis and preserving survival under these conditions. Here, we examine recent advances in the characterization of the Dsb-like, Salmonella-specific Scs system. This system includes the ScsC/ScsB pair of Cu+-binding proteins with thiol-oxidoreductase activity, an alternative ScsB-partner, the membrane-linked ScsD, and a likely associated protein, ScsA, with a role in peroxide resistance. We discuss the acquisition of the scsABCD locus and its integration into a global regulatory pathway directing envelope response to Cu stress during the evolution of pathogens that also harbor the canonical Dsb systems. The evidence suggests that the canonical Dsb systems cannot satisfy the extra demands that the host-pathogen interface imposes to preserve functional thiol groups. This resulted in the acquisition of the Scs system by Salmonella. We propose that the ScsABCD complex evolved to connect Cu and redox stress responses in this pathogen as well as in other bacterial pathogens.

Assuntos

Proteínas de Bactérias , Proteínas de Transporte , Cobre , Salmonella , Proteínas de Bactérias/metabolismo , Cobre/metabolismo , Homeostase , Oxirredução , Oxirredutases/metabolismo , Salmonella/metabolismo , Compostos de Sulfidrila , Proteínas de Transporte/metabolismo

RESUMO

Objective: The antimicrobial activities of the synergistic combination of carvacrol and polymyxin B against polymyxin-resistant Klebsiella pneumoniae were evaluated. Methods: The methods employed checkerboard assays to investigate synergism, biofilm inhibition assessment and membrane integrity assay. In addition, the study included in vivo evaluation using a mouse infection model. Results: The checkerboard method evaluated 48 combinations, with 23 indicating synergistic action. Among these, carvacrol 10 mg/kg plus polymyxin B 2 mg/kg exhibited in vivo antimicrobial activity in a mouse model of infection, resulting in increased survival and a significant decrease in bacterial load in the blood. Conclusion: Polymyxin in synergy with carvacrol represents a promising alternative to be explored in the development of new antimicrobials.

---

In this study, we wanted to find a new way to fight a bacteria called Klebsiella pneumoniae, which is not easily killed by medication. We mixed two drugs, carvacrol and polymyxin B, to see if they would work together to fight the bacteria. We found that the mixed treatment helped to kill the bacteria. We also tried this mixed treatment in sick mice, and they got better. Our study shows that this mixed treatment might be a new way to fight bacteria that are hard to kill with regular drugs. Next, we hope to learn more about how it works.

Assuntos

Anti-Infecciosos , Cimenos , Polimixina B , Polimixina B/farmacologia , Antibacterianos/farmacologia , Klebsiella pneumoniae , Polimixinas , Sinergismo Farmacológico , Testes de Sensibilidade Microbiana

RESUMO

Pork is one of the most commonly consumed meats, and its safety has always been a concern. Recently, safety incidents caused by chemical or biological contamination such as drug residues, heavy metals, and pathogenic microorganisms in pork have been reported, and the safety of pork is a cause for concern. Salmonella spp. is one of the important foodborne pathogens that threaten human health. Pork is a high-risk vector food for Salmonella spp. infection. The assessment of the safety risk of Salmonella spp. in pork is conducive to the prevention of related foodborne diseases. In this paper, risk assessment models for Salmonella spp. in meat were developed. The quantitative risk assessment model for Salmonella spp. based on the pork supply chain showed that the annual number of cases of salmonellosis due to pork consumption in China is approximately 27 per 10,000 males and 24 per 10,000 females. Sensitivity analysis showed that the main factors affecting the risk of Salmonella spp. in pork were the display temperature, display time, and Salmonella spp. contamination concentration in pork at the sale.

Assuntos

Carne de Porco , Carne Vermelha , Infecções por Salmonella , Animais , Suínos , Humanos , Salmonella/genética , Carne Vermelha/microbiologia , Carne de Porco/análise , Manipulação de Alimentos , Carne/microbiologia , Medição de Risco , China/epidemiologia , Microbiologia de Alimentos , Contaminação de Alimentos/análise

RESUMO

Antimicrobial resistance is known to be one of the greatest global threats to human health, and is one of the main causes of death worldwide. In this scenario, polymyxins are last-resort antibiotics to treat infections caused by multidrug-resistant bacteria. Currently, the reference test to evaluate the susceptibility of isolates to polymyxins is the broth microdilution method; however, this technique has numerous complications and challenges for use in laboratory routines. Several phenotypic methods have been reported as being promising for implementation in routine diagnostics, including the BMD commercial test, rapid polymyxin NP test, polymyxin elution test, culture medium with polymyxins, and the Polymyxin Drop Test, which require materials for use in routines and must be easy to perform. Furthermore, Sensititre®, molecular tests, MALDI-TOF MS, and Raman spectroscopy present reliable results, but the equipment is not found in most microbiology laboratories. In this context, this review discusses the main laboratory methodologies that allow the detection of resistance to polymyxins, elucidating the challenges and perspectives.

RESUMO

In intensive care units (ICUs), infection rates range from 18 to 54%, which is five to ten times higher than those observed in other hospital units, with a mortality rate of 9% to 60%. In recent decades, the susceptibility pattern has changed and Gram-Negative Bacteria (GNB) have become a threat due to their high frequency of multidrug resistance associated with a scarcity of therapeutic options. However, the drugs Ceftolozane/Tazobactam (C/T) and Ceftazidime/Avibactam (C/A) are demonstrating good clinical and microbiological response in the treatment of severe nosocomial infections. Therefore, this study aims to evaluate the clinical outcome of patients with severe infections caused by Multidrug-Resistant (MDR) GNB treated with C/T and C/A. Our study evaluates a total of 131 patients who received treatment with C/T and C/A due to infections caused by MDR GNB within the period from 2018 to 2021. The main infections were urinary tract (46,6%) and respiratory (26,7%) infections. Pseudomonas aeruginosa was the prevailing agent in the sample evaluation (34.3%), followed by Klebsiella pneumoniae (30,1%). About 54,9% of patients showed a favorable response, with culture negativation in 66,4% of the samples, with no discrepancy in negativations when comparing ages: 67,7% in young and 66% in elderly patients. Among the patients, 62,6% received monotherapy with C/T and C/A with a better response observed with monotherapy compared to combination therapy (58,6% vs 41,4%). The overall mortality rate was 45%, with MDR GNB infections responsible for 33,9% of these deaths, and the others (66,1%) due to factors such as oncological, hematological, and degenerative neurological diseases. In regards to hematological aspect, 35,1% of patients showed changes, with 28,2% of them presenting anemia, 4,5% thrombocytopenia, and 2,5% thrombocytosis. Concerning the use of invasive devices, higher mortality was observed in patients on mechanical ventilation (52%). In this manner, it was possible to observe that therapy with C/T and C/A yielded a favorable clinical outcome in patients with severe infections caused by MDR GNB in the study. These drugs also demonstrated good tolerability regardless of age or the presence of preexisting comorbidities and were deemed safe when assessing adverse effects. Our data also demonstrate the importance of determining the mechanism of resistance to carbapenems so that these drugs can be used more effectively and rationally.

Assuntos

Antibacterianos , Compostos Azabicíclicos , Ceftazidima , Humanos , Idoso , Ceftazidima/uso terapêutico , Ceftazidima/farmacologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Cefalosporinas/farmacologia , Cefalosporinas/uso terapêutico , Tazobactam/uso terapêutico , Tazobactam/farmacologia , Farmacorresistência Bacteriana Múltipla , Bactérias Gram-Negativas , Unidades de Terapia Intensiva , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa

RESUMO

INTRODUCTION: Shorter courses of antimicrobials have been shown to be non-inferior to longer, "traditional" duration of therapies, including for some severe healthcare-associated infections, with a few exceptions. However, evidence is lacking regarding shorter regimes against severe infections by multidrug-resistant Gram-negative bacteria (MDR-GNB), which are often caused by distinct strains and commonly treated with second-line antimicrobials. In the duratiOn of theraPy in severe infecTIons by MultIdrug-reSistant gram-nEgative bacteria (OPTIMISE) trial, we aim to assess the non-inferiority of 7-day versus 14-day antimicrobial therapy in critically ill patients with severe infections caused by MDR-GNB. METHODS: This is a randomized, multicenter, open-label, parallel controlled trial to assess the non-inferiority of 7-day versus 14-day of adequate antimicrobial therapy for intensive care unit (ICU)-acquired severe infections by MDR-GNB. Adult patients with severe infections by MDR-GNB initiated after 48 h of ICU admission are screened for eligibility. Patients are eligible if they proved to be hemodynamically stable and without fever for at least 48 h on the 7th day of adequate antimicrobial therapy. After consenting, patients are 1:1 randomized to discontinue antimicrobial therapy on the 7th (± 1) day or to continue for a total of 14th (± 1) days. PLANNED OUTCOMES: The primary outcome is treatment failure, defined as death or relapse of infection within 28 days after randomization. Non-inferiority will be achieved if the upper edge of the two-tailed 95% confidence interval of the difference between the clinical failure rate in the 7-day and the 14-day group is not higher than 10%. CONCLUSION: The OPTIMISE trial is the first randomized controlled trial specifically designed to assess the duration of antimicrobial therapy in patients with severe infections by MDR-GNB. TRIAL REGISTRATION: ClinicalTrials.gov, NCT05210387. Registered on 27 January 2022. Seven Versus 14 Days of Antibiotic Therapy for Multidrug-resistant Gram-negative Bacilli Infections (OPTIMISE).