RESUMEN

Urinary tract infection is one of the last diseases prevalent in humans, with various causative agents affecting 250 million people annually, This study analyzed UTIs in Iraqi patients caused by Escherichia coli. ESBL enzymes contribute to antibiotic resistance. The research aimed to analyze ESBL gene frequency, resistance patterns, and genetic diversity of E. coli strains; Between Dec 2020 and May 2021, 200 urine samples were collected, cultured on blood agar, EMB, and MacConkey's plates, samples incubated at 37 °C for 24 h. Positive samples (> 100 cfu/ml) underwent Kirby-Bauer and CLSI antibiotic susceptibility testing. PCR detected virulence genes, Beta-lactamase coding genes, and biofilm-associated resistance genes in E. coli isolates; Out of 200 isolates, 80% comprised Gram-positive and Gram-negative bacteria. Specifically, 120 isolates (60%) were Gram-negative, while 40 isolates (20%) were Gram-positive. Among Gram-negative isolates, 20% were identified as E. coli. Remarkably, all E. coli strains showed resistance to all tested antibiotics, ranging from 80 to 95% resistance. The E. coli isolates harbored three identified resistance genes: blaTEM, blaSHV, and blaCTXM. Regarding biofilm production, 10% showed no formation, 12% weak formation, 62% moderate formation, and 16% strong formation; our study found that pathogenic E. coli caused 20% of UTIs. The majority of studied E. coli strains from UTI patients carried the identified virulence genes, which are vital for infection development and persistence.

RESUMEN

The growing resistance of bacteria to antibiotics is one of the main public health problems nowadays. The influence of silver nanoparticle (AgNP) pretreatment of 220 cows with mastitis on the susceptibility of Staphylococcus epidermidis bacteria to 31 antibiotics was studied. The obtained results were compared with the previous results for Escherichia coli, Streptococcus dysgalactiae, and Staphylococcus aureus. For all four bacteria, an increase in susceptibility (9.5-21.2%) to 31 antibiotics after cow treatment with AgNPs was revealed, while after first-line antibiotic drug treatment as expected, the susceptibility decreased (11.3-27.3%). These effects were explained by (1) the increase in the contribution of isolates with efflux effect after antibiotic treatments and its decrease after AgNP treatment and (2) the changes in bacteria adhesion and anti-lysozyme activity after these treatments. The effect of the increasing antibacterial activity of antibiotics after AgNP treatment was the most pronounced in the case of E. coli and was minimal in the case of S. epidermidis. With AgNP treatment, the time of recovery decreased by 26.8-48.4% compared to the time of recovery after treatment with the first-line antibiotic drugs. The AgNP treatment allows for achieving the partial restoration of the activity of antibiotics.

RESUMEN

Chronic rhinosinusitis (CRS) is a significant public health problem. Bacterial colonization and impaired mucociliary clearance play a significant role in the inflammatory process. Several inflammatory pathways and host defense elements are altered in CRS, which may contribute to observed differences in the microbiome. To date, researching CRS has been difficult due to limited access to the studied tissue and a lack of available biomarkers. Ongoing scientific research is increasingly based on simple and objective analytical methods, including sensors, detection with PCR, and sequencing. Future research on microbiota and human factors should also include genomics, transcriptomics, and metabolomics approaches. This report analyzes the changes that occur in the paranasal sinuses of people with acute and chronic rhinosinusitis, the composition of the microbiota, the human genetic markers that may shed light on the predisposition to CRS, and the advantages and disadvantages of classical and molecular diagnostic methods, as well as addressing the difficulties of sinusitis treatment.

Asunto(s)

Senos Paranasales , Rinitis , Rinosinusitis , Sinusitis , Humanos , Marcadores Genéticos , Sinusitis/diagnóstico , Sinusitis/genética , Sinusitis/microbiología , Enfermedad Crónica , Rinitis/etiología , Rinitis/genética

RESUMEN

The increase in bacterial resistance to antibiotics is a global problem for public health. In our previous works, it was shown that the application of AgNPs in cow mastitis treatment increased S. aureus and S. dysgalactiae susceptibility to 31 antibiotics due to a decrease in the bacterial efflux effect. The aim of the present work was to shed light on whether the change in adhesive and anti-lysozyme activities caused by AgNPs also contribute to the restoration of bacterial susceptibility to antibiotics. In vivo sampling was performed before and after cow mastitis treatments with antibiotics or AgNPs. The isolates were identified, and the adhesive and anti-lysozyme activities were assessed. These data were compared with the results obtained for in vitro pre-treatment of reference bacteria with AgNPs or antibiotics. The present study revealed that bacterial treatments in vitro and in vivo with AgNPs: (1) decrease the bacterial ability to adhere to cells to start an infection and (2) decrease bacterial anti-lysozyme activity, thereby enhancing the activity of lysozyme, a natural "antibiotic" present in living organisms. The obtained data contribute to the perspective of the future application of AgNPs for recovering the activity of antibiotics rapidly disappearing from the market.

Asunto(s)

Mastitis , Nanopartículas del Metal , Animales , Femenino , Bovinos , Humanos , Antibacterianos/farmacología , Staphylococcus aureus , Pruebas de Sensibilidad Microbiana , Bacterias , Mastitis/microbiología

RESUMEN

Pseudomonas (P.) aeruginosa is a bacterium responsible for severe infections that have become a real concern in hospital environments. Nosocomial infections caused by P. aeruginosa are often hard to treat because of its intrinsic resistance and remarkable ability to acquire further resistance mechanisms to multiple groups of antimicrobial agents. Thus, rapid determination of the susceptibility of P. aeruginosa isolates to antibiotics is crucial for effective treatment. The current methods used for susceptibility determination are time-consuming; hence the importance of developing a new method. Fourier-transform infra-red (FTIR) spectroscopy is known as a rapid and sensitive diagnostic tool, with the ability to detect minor abnormal molecular changes including those associated with the development of antibiotic- resistant bacteria. The main goal of this study is to evaluate the potential of FTIR spectroscopy together with machine learning algorithms, to determine the susceptibility of P. aeruginosa to different antibiotics in a time span of ∼20 min after the first culture. For this goal, 590 isolates of P. aeruginosa, obtained from different infection sites of various patients, were measured by FTIR spectroscopy and analyzed by machine learning algorithms. We have successfully determined the susceptibility of P. aeruginosa to various antibiotics with an accuracy of 82-90%.

Asunto(s)

Infecciones por Pseudomonas , Pseudomonas aeruginosa , Antibacterianos/farmacología , Humanos , Aprendizaje Automático , Pruebas de Sensibilidad Microbiana , Pseudomonas , Infecciones por Pseudomonas/tratamiento farmacológico , Infecciones por Pseudomonas/microbiología , Análisis Espectral

RESUMEN

Neonatal sepsis is a leading cause of morbidity and mortality, and knowledge of bacterial patterns and susceptibility to antibiotics is essential to design therapeutic guidelines. To determine the bacterial aetiology and antibiotic resistance patterns in neonatal sepsis, a prospective, cross-sectional, hospital-based study was conducted in a large paediatric emergency hospital in Khartoum State, Sudan, over a 6-month period. All newborn infants with a clinical diagnosis of sepsis were included in the study and had a blood sample collected for culture and sensitivity. The World Health Organization case definition of neonatal sepsis in conjunction with the Integrated Management of Childhood Illnesses criteria was used to select patients. A total of 170 newborn infants fulfilled the study inclusion criteria. The median age at presentation was 4-7 days and blood culture was positive in 31%. Early-onset neonatal sepsis was present in 30% of cases, while 70% were late-onset. Gram-positive organisms accounted for 58% of the total isolates, and 38% were Gram-negative organisms. Staphylococcus aureus was the most prevalent organism (55% of all isolates) and 72% of these were methicillin-resistant which showed 100% sensitivity to vancomycin and 90% to gentamycin. Pseudomonas aeruginosa was the commonest Gram-negative organism in both early and late-onset sepsis and the second commonest isolated organism, accounting for 19% of cases. All Gram-negative organisms were 100% sensitive to imipenem, meropenem and ciprofloxacin. Both Gram-positive and Gram-negative organisms were highly resistant to benzylpenicillin and cefotaxime, the commonly used empiric antibiotics in neonatal sepsis.

RESUMEN

We examined the cell-surface physicochemical properties, the biofilm formation capability and the antibiotic susceptibility in dispersed cells (from an artificial biofilm of alginate beads) and compared with their planktonic (free-swimming) counterparts. The strains used were from different origins, such as clinical (Acinetobacter baumannii AB4), cosmetic industry (Klebsiella oxytoca EU213, Pseudomonas aeruginosa EU190), and environmental (Halomonas venusta MAT28). In general, dispersed cells adhered better to surfaces (measured as the "biofilm index") and had a greater hydrophobicity [measured as the microbial affinity to solvents (MATS)] than planktonic cells. The susceptibility to two antibiotics (ciprofloxacin and tetracycline) of dispersed cells was higher compared with that of their planktonic counterparts (tested by the "bactericidal index"). Dispersed and planktonic cells exhibited differences in cell permeability, especially in efflux pump activity, which could be related to the differences observed in susceptibility to antibiotics. At 1 h of biofilm formation in microtiter plates, dispersed cells treated with therapeutic concentration of ciprofloxacin yielded a lower biofilm index than the control dispersed cells without ciprofloxacin. With respect to the planktonic cells, the biofilm index was similar with and without the ciprofloxacin treatment. In both cases there were a reduction of the number of bacteria measured as viable count of the supernatant. The lower biofilm formation in dispersed cells with ciprofloxacin treatment may be due to a significant increase of biofilm disruption with respect to the biofilm from planktonic cells. From a clinical point of view, biofilms formed on medical devices such as catheters, cells that can be related to an infection were the dispersed cells. Our results showed that early treatment with ciprofloxacin of dispersed cells could diminishe bacterial dispersion and facilitate the partial elimination of the new biofilm formed.

Asunto(s)

Antibacterianos/farmacología , Biopelículas/crecimiento & desarrollo , Microbiología Ambiental , Plancton/efectos de los fármacos , Plancton/fisiología , Adhesión Bacteriana , Humanos , Pruebas de Sensibilidad Microbiana

RESUMEN

AIM: To evaluate the epidemiology and outcomes of culture-positive spontaneous bacterial peritonitis (SBP) and spontaneous bacteremia (SB) in decompensated cirrhosis. METHODS: We prospectively collected clinical, laboratory characteristics, type of administered antibiotic, susceptibility and resistance of bacteria to antibiotics in one hundred thirty cases (68.5% males) with positive ascitic fluid and/or blood cultures during the period from January 1, 2012 to May 30, 2014. All patients with SBP had polymorphonuclear cell count in ascitic fluid > 250/mm(3). In patients with SB a thorough study did not reveal any other cause of bacteremia. The patients were followed-up for a 30-d period following diagnosis of the infection. The final outcome of the patients was recorded in the end of follow-up and comparison among 3 groups of patients according to the pattern of drug resistance was performed. RESULTS: Gram-positive-cocci (GPC) were found in half of the cases. The most prevalent organisms in a descending order were Escherichia coli (33), Enterococcus spp (30), Streptococcus spp (25), Klebsiella pneumonia (16), S. aureus (8), Pseudomanas aeruginosa (5), other Gram-negative-bacteria (GNB) (11) and anaerobes (2). Overall, 20.8% of isolates were multidrug-resistant (MDR) and 10% extensively drug-resistant (XDR). Health-care-associated (HCA) and/or nosocomial infections were present in 100% of MDR/XDR and in 65.5% of non-DR cases. Meropenem was the empirically prescribed antibiotic in HCA/nosocomial infections showing a drug-resistance rate of 30.7% while third generation cephalosporins of 43.8%. Meropenem was ineffective on both XDR bacteria and Enterococcus faecium (E. faecium). All but one XDR were susceptible to colistin while all GPC (including E. faecium) and the 86% of GNB to tigecycline. Overall 30-d mortality was 37.7% (69.2% for XDR and 34.2% for the rest of the patients) (log rank, P = 0.015). In multivariate analysis, factors adversely affecting outcome included XDR infection (HR = 2.263, 95%CI: 1.005-5.095, P = 0.049), creatinine (HR = 1.125, 95%CI: 1.024-1.236, P = 0.015) and INR (HR =1.553, 95%CI: 1.106-2.180, P = 0.011). CONCLUSION: XDR bacteria are an independent life-threatening factor in SBP/SB. Strategies aiming at restricting antibiotic overuse and rapid identification of the responsible bacteria could help improve survival.

Asunto(s)

Bacteriemia/microbiología , Bacteriemia/mortalidad , Infección Hospitalaria/microbiología , Infección Hospitalaria/mortalidad , Farmacorresistencia Bacteriana Múltiple , Cirrosis Hepática/complicaciones , Peritonitis/microbiología , Peritonitis/mortalidad , Anciano , Antibacterianos/uso terapéutico , Bacteriemia/diagnóstico , Bacteriemia/tratamiento farmacológico , Infección Hospitalaria/diagnóstico , Infección Hospitalaria/tratamiento farmacológico , Femenino , Humanos , Estimación de Kaplan-Meier , Cirrosis Hepática/diagnóstico , Cirrosis Hepática/mortalidad , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Peritonitis/diagnóstico , Peritonitis/tratamiento farmacológico , Valor Predictivo de las Pruebas , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento

RESUMEN

Pseudomonas aeruginosa es parte de un grupo de bacterias ubicuas en el ambiente. Su elevado nivel de resistencia intrínseca a los antibióticos, unido a su capacidad para desarrollar nuevos mecanismos de resistencia, hacen de este patógeno oportunista uno de los más difíciles de tratar. El objetivo del presente estudio fue evaluar la susceptibilidad a antibióticos de P. aeruginosa aislada del agua de consumo humano de la comunidad Santa Rosa de Agua, Maracaibo, estado Zulia, así como la detección de enzimas de resistencia a antibióticos. Se analizaron 40 muestras. El aislamiento de Pseudomonas se realizó en caldo asparagina y agar cetrimide, con posterior identificación bioquímica. La susceptibilidad a antibióticos se determinó, según el método de difusión en disco y la producción de enzimas mediante la sinergia de discos. El 92,5% de las muestras presentaron Pseudomonas, lográndose aislar 22 cepas de P. aeruginosa. El mayor porcentaje de cepas resistentes fue ante aztreonam (36,4%), seguido por ceftazidima (22,7%), cefepime (13,6%) y tobramicina (4,5%). El 18% de las cepas resultaron positivas para la determinación de BLEE mediante disociación de betalactámicos, así mismo el 9% positivas para carbapenemasas y metalobetalactamasas.

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Pseudomonas aeruginosa is a group of ubiquitous bacteria found in the environment. Its high level of intrinsic antibiotic resistance, coupled with its ability to develop new mechanisms of resistance, make this opportunistic pathogen one of the most difficult to treat. The aim of this study was to evaluate the antibiotic susceptibility of P. aeruginosa isolated from drinking water from Santa Rosa de Agua community, Maracaibo, Zulia State, as well as the detection of antibiotic resistance enzymes. Forty isolates were analyzed using asparagine agar broth and cetrimide, with subsequent biochemical identification. Antibiotic susceptibility was determined by the disc diffusion method and enzyme production was studied by combined disc diffusion. Of the specimens studied 92.5% were positive for Pseudomonas, of which 22 isolates were P. aeruginosa. The highest percentage of resistant strains were to aztreonam (36.4%), followed by ceftazidime (22.7%), cefepime (13.6%) and tobramycin (4.5%). The determination for extended-spectrum beta-lactamases (ESBL) was 18% positive and 9% positive for carbapenemases (KPC) and metallo-beta-lactamases (MBL).

RESUMEN

We investigated the genetic similarities and expression of the MexAB-OprM efflux pump system in different clones of multiresistant Pseudomonas aeruginosa strains collected from 2002 to 2009 at two intensive care units (ICU). Regulatory and structural genes mexB, mexR, and mexA were found in 99%, 98%, and 94% of tested strains, respectively. The presence of class 1 integron was found in 90% of the strains, while class 2 integron in only one strain (Psa506). Class 3 integron was not found in any of the tested strains. Among the eleven clones identified, only two clones, I and D, exhibited higher levels of mexB gene expression than the other clones. Clone I had the highest expression (FC = 10.36, p < 0.05). The results of our study indicated a high level of MexAB-OprM pump expression in groups of strains isolated in the years 2008-2009 (FC = 12.92, p < 0.03) and 2002-2006 (FC = 5.14, p < 0.03). There were no statistically significant differences in resistance to all tested antibiotics among the various clones. The high level of antimicrobial resistance may have been due to the coexistence of different resistance mechanisms among the studied P. aeruginosa strains. However, this does not exclude the contribution of the MexAB-OprM pump, particularly in resistance to meropenem and ciprofloxacin.

Asunto(s)

Antibacterianos/uso terapéutico , Proteínas de la Membrana Bacteriana Externa/genética , Proteínas de Transporte de Membrana/genética , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/genética , Hospitales Universitarios , Humanos , Unidades de Cuidados Intensivos , Polonia

RESUMEN

INTRODUCTION: Twenty-eight isolates of extended-spectrum ß-lactamase (ESBL)-positive Klebsiella pneumoniae were studied. MATERIAL AND METHODS: The strains were cultured from different clinical specimens obtained from children hospitalised at the University Hospital in Bydgoszcz. Seventeen strains were isolated from colonization and eleven from clinical infection. Isolation and identification of bacteria were performed using routine methods at the clinical microbiology laboratory. Production of ESBL was assessed using the double disk synergy test. The susceptibility to imipenem and tigecycline was tested by the Etest. The susceptibility to gentamicin and ciprofloxacin was tested by the agar dilution method. The genomic DNA was extracted from the strains separated by pulsed-field gel electrophoresis (PFGE) after digesting with XbaI endonuclease. RESULTS: Among analysed K. pneumoniae strains all were susceptible to imipenem, 21 (75.0%) were susceptible to tigecycline, 14 (50.0%) to gentamicin and 5 (17.9%) to ciprofloxacin. Molecular typing results revealed a great genetic diversity among K. pneumoniae isolates. All repeated PFGE patterns were detected in seven K. pneumoniae isolates. Among identical K. pneumoniae strains four susceptibility patterns were detected. CONCLUSIONS: The results of the study suggest that establishing strains' similarity in epidemiological investigations should be based on results obtained by several methods, and that each phenotyping method should be complemented with genetic research.