Pyogenic liver abscess caused by an atypical hypervirulent Klebsiella pneumoniae K1-ST23 in Mexico.

Hypervirulent K. pneumoniae infection has been raising worldwide and is one of the major causes of community-acquired pyogenic liver abscess. We described a case report of pyogenic liver abscess caused by an atypical hypervirulent (non-hypermucoviscous) K. pneumoniae K1 ST23 in a diabetic Asian patient who resided in Mexico. The susceptibility to antimicrobials, pathogenicity, molecular and genomic analysis were determined. A man from Guangdong (China) with a recent diagnosis of diabetes mellitus was admitted to the hospital, and he denied traveling in the last 3 months. A computed tomography revealed a right lobe liver abscess. On the third day after admission a Klebsiella pneumoniae isolate (14652) was obtained. The isolate corresponded to a susceptible K. pneumoniae with capsular type K1 and ST23 (CG23) and exhibited a non-hypermucoviscous phenotype. The isolate 14652 was genetically related to the globally distributed lineage ST23-KL1. This study describes the first case in Mexico of K. pneumoniae capsular type K1 and ST23 with an atypical hypervirulent phenotype.

Genome sequence of a virulent and hypermucoviscous-like Klebsiella michiganensis clinical isolate.

OBJECTIVES: The hypermucoviscous-like phenotype has been described in Klebsiella pneumoniae species complex (KpSC) and was described as a contributor of increased virulence. This study described the characterization and whole-genome sequencing of an antibiotic susceptible and hypermucoviscous-like Klebsiella michiganensis 9273 clinical isolate. DATA DESCRIPTION: Here, we report the genome sequence of a K. michiganensis clinical isolate obtained from a urinary tract infection exhibiting the hypermucoviscous-like phenotype. The draft genome sequence consisted of 145 contigs and ~ 6.6 Mb genome size. The annotation revealed 6648 coding DNA sequences and 56 tRNA genes. The strain belongs to the sequence type (ST) 50, and the OXY-1 beta-lactam resistance gene, aph(3')-Ia gene for aminoglycoside resistance and multidrug efflux pumps were identified. The fyuA siderophore receptor of yersiniabactin siderophore was identified. Increased virulence was observed in Galleria mellonella larvae model and increased capsule production was determined by uronic acid quantification. The clinical implications of this phenotype are unknown, but the patient outcome might worsen compared to susceptible- or MDR-classical K. michiganensis isolates.

Molecular and Genomic Insights of mcr-1-Producing Escherichia coli Isolates from Piglets.

The use of colistin in food-producing animals favors the emergence and spread of colistin-resistant strains. Here, we investigated the occurrence and molecular mechanisms of colistin resistance among E. coli isolates from a Mexican piglet farm. A collection of 175 cephalosporin-resistant colonies from swine fecal samples were recovered. The colistin resistance phenotype was identified by rapid polymyxin test and the mcr-type genes were screened by PCR. We assessed the colistin-resistant strains by antimicrobial susceptibility test, pulse-field gel electrophoresis, plasmid profile, and mating experiments. Whole-Genome Sequencing data was used to explore the resistome, virulome, and mobilome of colistin-resistant strains. A total of four colistin-resistant E. coli were identified from the cefotaxime-resistant colonies. All harbored the plasmid-borne mcr-1 gene, which was located on conjugative 170-kb IncHI-2 plasmid co-carrying ESBLs genes. Thus, high antimicrobial resistance rates were observed for several antibiotic families. In the RC2-007 strain, the mcr-1 gene was located as part of a prophage carried on non-conjugative 100-kb-plasmid, which upon being transformed into K. variicola strain increased the polymyxin resistance 2-fold. The genomic analysis showed a broad resistome and virulome. Our findings suggest that colistin resistance followed independent acquisition pathways as clonal and non-genetically related mcr-1-harboring strains were identified. These E. coli isolates represent a reservoir of antibiotic resistance and virulence genes in animals for human consumption which could be potentially propagated into other interfaces.

Diarrheagenic Escherichia coli pathotypes isolated from a swine farm in a region of Morelos state, Mexico / Patotipos diarreicos de Escherichia coli aislados de una granja porcina en una región del estado de Morelos, México

Abstract: Objective: Determine the frequency of diarrheagenic Escherichia coli pathotypes colonizing swine. Materials and methods: E. coli strains isolated of fecal samples from 280 swine, produced for local consumption, in a semi-technical farm of Morelos state (central Mexico), were tested to identify the diarrheagenic E. coli pathotypes by multiplex PCR. Pulsed-field gel electrophoresis (PFGE) were determined for the study of genetic diversity between pathigenic E. coli strains. Results: Of the 521-diarrheagenic E. coli isolates examined, 50 (9.6%) were positive for at least one virulence gene in 42 different animals. Thus, 15% (42/280) of the swine in this farm were colonized with pathogenic E. coli. Among the E. coli isolates, the pathotype EPEC (6.5%) was the most frequently, followed by EHEC (2.3%), ETEC and EIEC (0.4%). The study of genetic diversity, carried out by PFGE of 40 representative isolates, revealed 25 distinct restriction profiles clustered in 21 groups (A-U). Conclusions: In this study, four different E. coli pathotypes were found among swine colonized by E. coli in this farm. Thus, these swine are reservoirs for these virulent bacteria and there is potential risk of causing diarrhea in swine and in the population consuming the meat.

Resumen: Objetivo: Determinar la frecuencia de patotipos diarreicos de Escherichia coli que colonizan cerdos. Material y métodos: Se analizaron cepas de E. coli aisladas de muestras fecales de 280 cerdos, producidas para consumo local, en una granja del estado de Morelos (centro de México) para identificar los patotipos diarreicos de E. coli por PCR multiplex. Se determinó la electroforesis en gel de campo pulsado (PFGE) para el estudio de la diversidad genética entre cepas patógenas de E. coli. Resultados: De los 521 aislados de E. coli con patotipos diarreicos examinados, 50 (9.6%) fueron positivos para al menos un gen de virulencia en 42 animales diferentes. Así, 15% (42/280 porcinos) fueron colonizados con E. coli patógeno. Entre los aislados de E. coli de porcinos, el patotipo EPEC (6.5%) fue el más frecuente, seguido por EHEC (2.3%), ETEC y EIEC (0.4%). El estudio de la diversidad genética, realizado por PFGE de 40 cepas representativas, reveló 25 perfiles de restricción distintos agrupados en 21 grupos (A-U). Conclusiones: En este estudio, se encontraron cuatro diferentes patotipos de E. coli entre los cerdos colonizados por E. coli. Estos cerdos son reservorios de estas bacterias virulentas y existe un riesgo potencial de causar diarrea en los cerdos y en la población que consume la carne.

Diarrheagenic Escherichia coli pathotypes isolated from a swine farm in a region of Morelos state, Mexico.

OBJECTIVE: Determine the frequency of diarrheagenic Escherichia coli pathotypes colonizing swine. MATERIALS AND METHODS: E. coli strains isolated of fecal samples from 280 swine, produced for local consumption, in a semi-technical farm of Morelos state, (central Mexico) were tested to identify the diarrheagenic E. coli pathotypes by multiplex PCR. RESULTS: Of the 521-diarrheagenic E. coli isolates examined, 50 (9.6%) were positive for at least one virulence gene in 42 different animals. Thus, 15% (42/280) of the swine in this farm were colonized with pathogenic E. coli. Among the E. coli isolates, the pathotype EPEC (6.5%) was the most frequently, followed by EHEC (2.3%), ETEC and EIEC (0.4%). CONCLUSIONS: In this study, four different E. coli pathotypes were found among swine colonized by E. coli in this farm. Thus, these swine are reservoirs for these virulent bacteria and there is potential risk of causing diarrhea in swine and in the population consuming the meat.

Draft Genome Sequence of a Multidrug- and Colistin-Resistant mcr-1-Producing Escherichia coli Isolate from a Swine Farm in Mexico.

A colistin-resistant mcr-1-carrying Escherichia coli strain, RC2-007, was isolated from a swine farm in Mexico. This extraintestinal and uropathogenic strain of E. coli belongs to serotype O89:H9 and sequence type 744. Assembly and annotation resulted in a 4.9-Mb draft genome that revealed the presence of plasmid-mediated mcr-1-ISApI1 genes as part of a prophage.

Outbreak Caused by blaOXA-72-Producing Acinetobacter baumannii ST417 Detected in Clinical and Environmental Isolates.

We characterized an outbreak of imipenem-resistant Acinetobacter baumannii with clinical and environmental isolates from a tertiary care hospital in San Luis Potosi, Mexico. During a 4-month period, a total of 32 nonrepetitive imipenem-resistant clinical isolates of A. baumannii were collected. All isolates were susceptible to colistin and tigecycline and resistant to cefepime, ceftazidime, ceftriaxone, imipenem, and meropenem. Genotyping by pulsed-field gel electrophoresis showed a major clone (A). Multilocus sequence type (MLST) analysis was performed, revealing sequence type (ST) 417 (ST417) and 208 (ST208). The blaIMP-, blaVIM-, blaGIM-, blaSIM-, blaNDM-type, and blaOXA-type (blaOXA-23-like, blaOXA-24-like, blaOXA-51-like, and blaOXA-58-like) genes were screened and showed that the blaOXA-51-like and blaOXA-24-like genes were present in all isolates. Sequencing and southern hybridization were performed, confirming the presence of the blaOXA-72 gene and its plasmid-borne nature. In addition, the blaOXA-72-XerC/XerD-like association was identified. These findings indicate that a clonal spread of blaOXA-72-producing A. baumannii ST417 had occurred throughout the hospital. The ST417 corresponded with a previous ST described in the United States.

Widespread of ESBL- and carbapenemase GES-type genes on carbapenem-resistant Pseudomonas aeruginosa clinical isolates: a multicenter study in Mexican hospitals.

The present work describes a prevalence of 36.2% of carbapenemases IMP-, VIM-, and GES-type on 124 imipenem-resistant Pseudomonas aeruginosa clinical isolates. The ESBL GES-19 and carbapenemase GES-20 genes were the most prevalent (84.4%) ß-lactamases among imipenem-resistant P. aeruginosa clinical isolates in Mexico. These genes are chromosomal encoded on embedded class 1 integron arrays.

Characteristics of KPC-2-producing Klebsiella pneumoniae (ST258) clinical isolates from outbreaks in 2 Mexican medical centers.

The KPC-producing Klebsiella pneumoniae sequence type 258 (ST258) is an important pathogen widely spread in nosocomial infections. In this study, we identified the KPC-2-producing K. pneumoniae clinical isolates of 2 unrelated outbreaks that corresponded to pandemic strain ST258. The isolates showed high resistance to cephalosporins, carbapenems, quinolones, and colistin. The KPC-2-producing K. pneumoniae isolates were compared to the previously studied KPC-3-producing K. pneumoniae isolates from an outbreak in Mexico; they showed an unrelated pulsed-field gel electrophoresis fingerprinting pattern and a different plasmid profile. The KPC-2 carbapenemase gene was identified in two 230- and 270-kb non-conjugative plasmids; however, 1 isolate transferred the KPC-2 gene onto an 80-kb plasmid. These findings endorse the need of carrying out a continuous molecular epidemiological surveillance of carbapenem-resistant isolates in hospitals in Mexico.

Infección por virus del papiloma humano en mujeres con y sin citología cervical anormal / Infection by the human papiloma virus in women with and without abnormal cervical cytology

Este estudio se realizó con el objetivo de definir la prevalencia de infección por el virus del papiloma humano (VPH) así como de anormalidades citológicas en 3,257 mujeres sexualmente activas entre 13 y 45 años de edad las cuales acudieron a su examen citológico rutinario en una clínica de un hospital urbano. Ciento cincuenta pacientes (4.6 por ciento) presentaron evidencia citológica de infección cervical por papilomavirus humano (Papanicolau anormal) Paralelamente, seleccionamos un grupo testigo (n=150) con exámenes citológicos cervicales negativos.Las células obtenidas por raspado, fueron analizadas por el método de PCR para la amplificación de DNA del HPV. La identificación de los genotipos se realizó por medio de sondas específicas para los tipos 6, 11, 16, 18 y 33.El DNA viral se detectó en 21/300 (7.0 por ciento de las pacientes. La prevalencia de VPH cervical en las mujeres con citología negativa fue de 5.3 por ciento (8/150) mientras que las que presentaron alguna alteración en el Pap tuvieron una prevalencia del 8.6 por ciento (13/150). El riesgo de infección por VPH parece estar relacionada con la edad, el inicio temprano de la actividad sexual y el número de parejas sexuales, tabaquismo o la historia de alguna enfermedad.

Presencia del virus Herpes simple-2 (HSV-2) en mujeres que asisten a una clínica de control de cáncer cervicouterino / Presence of virus Herpes Simplex-2 (HSV-2) in women attending a control clinic for cervicouterine cancer

En este estudio prospectivo, se reclutaron 284 mujeres aparentemente sanas, asistentes al programa de prevención cáncer cervicouterino por medio del Papanicolaou, a las cuales se les tomó material de secreciones cervicovaginales para cultivo en células obtenidas de prepucio humano, con el propósito de aislar y serotipificar el virus Herpes simple. En 12 mujeres (4.2 por ciento) se aisló y caracterizó la presencia del HSV-2. Al comparar algunos aspectos demográficos, educacionales y de vida sexual, entre las positivas y negativas al cultivo, se pudo establecer que hay una relación entre la presencia del virus y la edad, el inicio de la vida sexual, el número de parejas sexuales fijas u ocasionales, la baja escolaridad y menor ingreso económico. La presencia de cervicitis mucopurulenta, ulceraciones clásicas o pequeñas efracciones confluentes fueron marcadores relacionados con la presencia del virus, no así, las erosiones del área escamocolumnar del exocérvix, que forman parte de la patología cervical y que son producto de vida reproductiva. El conocimiento de la prevalencia de infección subclínica o asintomática, debe ser tomado en cuenta para la prevención a la pareja, así como el riesgo potencial de reactivación en posibles embarazos.