Prevalence of Fecal Carriage of CTX-M-15 Beta-Lactamase-Producing Escherichia coli in Healthy Children from a Rural Andean Village in Venezuela.

OBJECTIVES: Antimicrobial resistant extended-spectrum-ß-lactamase-producing Enterobacteriaceae (ESBL-PE) have been shown to be present in healthy communities. This study examined healthy children from the rural Andean village of Llano del Hato, Mérida, Venezuela, who have had little or no antibiotic exposure to determine the prevalence of fecal carriage of ESBL-producing Escherichia coli (ESBL-EC). METHODS: A total of 78 fecal samples were collected in healthy children aged from 1 to 5 years. ESBL-EC were selected in MacConkey agar plates with cefotaxime and further confirmed by the VITEK 2 system. ESBL were phenotypically detected and presence of bla genes and their variants were confirmed by molecular assays. Determination of phylogenetic groups was performed by PCR amplification. Risk factors associated with fecal carriage of ESBL-EC-positive isolates were analyzed using standard statistical methods. RESULTS: Of the 78 children studied, 27 (34.6%) carried ESBL-EC. All strains harbored the blaCTX-M-15 allele. Of these, 8 were co-producers of blaTEM-1, blaTEM-5, blaSHV-5 or blaSHV-12. Co-resistance to aminoglycosides and/or fluoroquinolones was observed in 9 strains. 51.9% of ESBL-EC isolates were classified within phylogroup A. A significant, positive correlation was found between age (≥2.5 - ≤5 years), food consumption patterns and ESBL-EC fecal carriage. CONCLUSION: This is the first study describing the high prevalence of fecal carriage of ESBL-EC expressing CTX-M-15- among very young, healthy children from a rural Andean village in Venezuela with scarce antibiotic exposure, underlining the importance of this population as a reservoir.

[Clinical and microbiological study of catheter-associated urinary tract infections in internal medicine services of a Venezuelan university hospital]. / Estudio clínico y microbiológico de la infección urinaria asociada a catéter, en los servicios de medicina interna de un hospital universitario venezolano.

OBJECTIVES: To determine the clinical and microbiological characteristics of catheter-associated urinary tract infections (CA-UTI) in patients admitted to the Internal Medicine services of the Hospital Universitario de Los Andes (HULA), Mérida, Venezuela and to establish the clonal distribution of multi-resistant Enterobacteriaceae that produce this infection. MATERIALS AND METHODS: Seventy-three adult patients with bladder catheterization were studied between January and July 2015. The microbiological processing of the urine samples was performed using conventional and automatized methods. Extended- spectrum beta-lactamase (ESBL) and carbapenemase were detected phenotypically. Clonal classification was determined using repetitive element sequence-based PCR. RESULTS: A total of 53.4% of the patients were male, and the average age was 50.6 years. The average time the catheter remained in the patient was 10.9 ± 6.5 days and 54.8% of patients had positive urine cultures. Yeasts were the main etiological agent (44.7%), followed by enterobacteria (29.8%). Enterobacteria, Pseudomonas aeruginosa, and Acinetobacter baumannii produced ESBL and carbapenemase associated with other resistance markers. Two clonal groups were identified in multi-resistant Escherichia coli and Klebsiella pneumoniae strains that circulated in the shock trauma unit in the adult emergency department. CONCLUSIONS: The findings in this study show the need to adopt strict criteria justifying the use of bladder catheterization and its duration, as well as the implementation of programs to prevent and control the spread of multi-resistant bacterial clones in patients with CA-UTI in the HULA Internal Medicine department.

Estudio clínico y microbiológico de la infección urinaria asociada a catéter, en los servicios de medicina interna de un hospital universitario venezolano / Clinical and microbiological study of catheter-associated urinary tract infections in internal medicine services of a Venezuelan university hospital

RESUMEN Objetivos Determinar las características clínicas y microbiológicas de las infecciones del tracto urinario asociadas a catéter (ITUAC) en pacientes hospitalizados en los servicios de Medicina Interna del Hospital Universitario de Los Andes (HULA), Mérida, Venezuela y establecer la distribución clonal de Enterobacteriaceae multirresistentes productoras de esta infección. Materiales y métodos Se estudiaron 73 pacientes adultos con cateterismo vesical, durante enero a julio de 2015. El procesamiento microbiológico de las muestras de orina se realizó por métodos convencionales y automatizados. Las β-lactamasas de espectro extendido (BLEE) y carbapenemasas fueron detectadas fenotípicamente. La tipificación clonal se determinó por la amplificación de secuencias repetitivas por PCR. Resultados El 53,4% de los pacientes eran varones, con una edad media de 50,6 años. El promedio de permanencia del catéter fue de 10,9 + 6,5 días/paciente. El 54,8% de los pacientes tuvo urocultivos positivos. Las levaduras fueron el principal agente etiológico (44,7%), seguido por las enterobacterias (29,8%). Las enterobacterias, Pseudomonas aeruginosa y Acinetobacter baumannii produjeron BLEE y carbapenemasas asociadas a otros marcadores de resistencia. Dos grupos clonales fueron identificados en cepas de E. coli y K. pneumoniae multirresistentes, los cuales circularon en la unidad de trauma shock de la emergencia de adulto. Conclusiones Los hallazgos de este estudio permiten evidenciar la necesidad de adoptar estrictos criterios que justifiquen el uso del catéter vesical y la duración del mismo, así como el implementar programas para prevenir y controlar la diseminación de clonas bacterianas multirresistentes en pacientes con ITUAC en los servicios de medicina interna del HULA.

ABSTRACT Objectives To determine the clinical and microbiological characteristics of catheter-associated urinary tract infections (CA-UTI) in patients admitted to the Internal Medicine services of the Hospital Universitario de Los Andes (HULA), Mérida, Venezuela and to establish the clonal distribution of multi-resistant Enterobacteriaceae that produce this infection. Materials and Methods Seventy-three adult patients with bladder catheterization were studied between January and July 2015. The microbiological processing of the urine samples was performed using conventional and automatized methods. Extended- spectrum beta-lactamase (ESBL) and carbapenemase were detected phenotypically. Clonal classification was determined using repetitive element sequence-based PCR. Results A total of 53.4% of the patients were male, and the average age was 50.6 years. The average time the catheter remained in the patient was 10.9 ± 6.5 days and 54.8% of patients had positive urine cultures. Yeasts were the main etiological agent (44.7%), followed by enterobacteria (29.8%). Enterobacteria, Pseudomonas aeruginosa, and Acinetobacter baumannii produced ESBL and carbapenemase associated with other resistance markers. Two clonal groups were identified in multi-resistant Escherichia coli and Klebsiella pneumoniae strains that circulated in the shock trauma unit in the adult emergency department. Conclusions The findings in this study show the need to adopt strict criteria justifying the use of bladder catheterization and its duration, as well as the implementation of programs to prevent and control the spread of multi-resistant bacterial clones in patients with CA-UTI in the HULA Internal Medicine department.

Nosocomial outbreak of extended-spectrum ß-lactamase-producing Enterobacter ludwigii co-harbouring CTX-M-8, SHV-12 and TEM-15 in a neonatal intensive care unit in Venezuela.

Enterobacter spp. have emerged as an important group of pathogens linked to outbreaks in neonatal intensive care units (NICUs), usually involving strains expressing extended-spectrum ß-lactamases (ESBLs). The aim of this study was to describe the first nosocomial bloodstream infection outbreak caused by Enterobacter ludwigii co-harbouring CTX-M-8, SHV-12 and TEM-15 in a NICU in a Venezuelan hospital. Initial bacterial identification was achieved by VITEK®2 system and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (VITEK® MS) and was subsequently confirmed by nucleotide sequencing of the 16S rDNA gene and hsp60 genotyping. Antimicrobial susceptibility testing was determined by AST-GN-299 VITEK®2 system cards and Etest strips. Isolates were typed by repetitive element sequence-based PCR (rep-PCR). Detection of blaESBL genes was carried out by molecular methods. Plasmid analysis included Southern blot and restriction pattern analysis, with transferability of resistance genes being assessed by conjugation. ESBL-producing E. ludwigii isolates were recovered from three neonates with bloodstream infection from the NICU in a 21-day period. rep-PCR fingerprints were indistinguishable among all of the isolates, strongly suggesting spread of a clonal strain. All isolates carried an ca. 56kb conjugative plasmid harbouring the blaCTX-M-8, blaSHV-12 and blaTEM-15 genes. Considering that isolation of ESBL-producing E. ludwigii remains an unusual phenomenon, not previously reported in Venezuela, the results of this study reveal the potential role of E. ludwigii as an emerging pathogen and highlight the importance of microbiological surveillance and judicious antibiotic use as measures to curb the emergence and spread of ESBL-producing bacteria.

First Description of KPC-2-Producing Klebsiella oxytoca Isolated from a Pediatric Patient with Nosocomial Pneumonia in Venezuela.

During the last decade, carbapenem resistance has emerged among clinical isolates of the Enterobacteriaceae family. This has been increasingly attributed to the production of ß-lactamases capable of hydrolyzing carbapenems. Among these enzymes, Klebsiella pneumoniae carbapenemases (KPCs) are the most frequently and clinically significant class-A carbapenemases. In this report, we describe the first nosocomial KPC-2-producing K. oxytoca isolated from a pediatric patient with pneumonia admitted to the intensive care unit at The Andes University Hospital, Mérida, Venezuela. This strain was resistant to several antibiotics including imipenem, ertapenem, and meropenem but remained susceptible to ciprofloxacin, colistin, and tigecycline. Conjugation assays demonstrated the transferability of all resistance determinants, except aminoglycosides. The isolate LMM-SA26 carried a ~21 kb conjugative plasmid that harbored the bla KPC-2, bla CTX-M-8, and bla TEM-15 genes. Although carbapenem resistance in the Enterobacteriaceae is still unusual in Venezuela, KPCs have a great potential to spread due to their localization on mobile genetic elements. Therefore, rapid detection of KPC-carrying bacteria with phenotypic and confirmatory molecular tests is essential to establish therapeutic options and effective control measures.

Characteristics of plasminogen binding to Trypanosoma cruzi epimastigotes.

The binding constants of the interaction between plasminogen and Trypanosoma cruzi epimastigotes were determined. An indirect method in which the bound plasminogen is detached from the cell by epsilon-aminocaproic acid and a direct method through biotinylated plasminogen were used. The analyses revealed a dissociation constant (Kd) from 0.4 to 1.2microM, these values being compatible with recognition in vivo. Moreover, epimastigotes from the gut of Rhodnius prolixus were able to bind plasminogen from the blood meal. Fragments derived from elastase digestion of plasminogen were tested for their ability to bind T. cruzi cells. The fragment with highest ability to interact with the parasite was miniplasminogen that bound in a concentration-dependent and saturable manner with a Kd similar to that for plasminogen. This binding was inhibited by epsilon-aminocaproic acid indicating that the lysine-binding site of kringle 5 may be responsible for the interaction of plasminogen with T. cruzi.