The aim of this study was to identify the presence of group CTX-M-9 extended spectrum beta-lactamases (ESBL) in clinical Escherichia coli isolates from pediatric patients. A total of 404 non-repeated ...positive ESBL E. coli isolates were collected from documented clinical infections in pediatric patients over a 2-year period. The identification and susceptibility profiles were determined using an automated system. Isolates that suggested ESBL production based on their resistance profiles to third and fourth generation cephalosporin and monobactam were selected. ESBL production was phenotypically confirmed using a diffusion method with cefotaxime and ceftazidime discs alone and in combination with clavulanic acid. blaESBL gene identification was performed through PCR amplification and sequencing. Pulsed Field Gel Electrophoresis (PFGE) and Multilocus Sequence Typing (MLST) were performed to establish the clonal relationships of the E. coli isolates. CTX-M-9-type ESBLs were detected in 2.5% of the isolates. The subtypes corresponded to blaCTX-M-14 (n = 4) and blaCTX-M-27 (n = 6). Additionally, coexistence with other beta-lactamases was observed. A clonal relationship was established in three isolates; the rest were classified as non-related. We found seven different sequence type (ST) in CTX-M-9- producing E. coli isolates. ST38 was the most frequent. This study is the first report in Mexico to document the presence of group CTX-M-9 ESBLs in E. coli isolates from pediatric patients.
Intestinal and extraintestinal infections by Aeromonas spp., remain controversial, due to the existence of healthy carriers of Aeromonas spp. In children under five years old, the diarrhea of ...infectious origin constitutes the second cause of mortality and remains a major concern for public health. The aim of this work was to detect the pheno/genotype of β-lactamases and class 1 integrons in Aeromonas spp., strains isolated from pediatric patients in a tertiary referral hospital in Mexico.
Sixty-six strains of Aeromonas spp., were isolated from clinical samples of pediatric origin and were identified by RFLP-PCR 16S rRNA. Resistance phenotype according to CLSI, genetic and phenotypic detection of extended-spectrum β-lactamases (ESBL) and metallo-b-lactamases (MBL) was performed. Finally, characterization of class 1 integrons was performed.
Aeromonas spp., strains of diarrheic origin were more predominant. A wide heterogeneity was detected, where A. caviae was the predominant specie. Second-generation cephalosporins, fluoroquinolones, and nitrofurans had best antimicrobial activity; moreover, antibiotics of the β-lactamic and lincosamides families showed lower inhibitory activity. Phenotypically, prevalences of 4.55% and 3.03% were detected for MBL (intestinal origin) and ESBL (extraintestinal origin), respectively. blaIMIS-cphA and blaTEM-1 genes, and nineteen class 1 integrons carrying two variants of cassettes corresponding to adenylyl transferases (aadA), and dihydrofolate reductases (dfrA). Monogenic array with aadA1 cassette was predominantly.
ESBL and class 1 integrons, in Aeromonas collected from pediatric patients, determines a major detection challenge for the clinical microbiology laboratory and represents a remarkable epidemiological risk of nosocomial spread of multidrug-resistant determinants.
Carbapenemases-producing Enterobacteriaceae (CPE) are a worldwide public health emergency. In Mexico, reports of CPE are limited, particularly in the pediatric population. Here, we describe the ...clinical, epidemiological, and molecular characteristics of seven consecutive cases in a third-level pediatric hospital in Mexico City over a four-month period during 2016.
The Enterobacteriaceae identified were three Escherichia coli strains (producing OXA-232, NDM-1 and KPC-2), two Klebsiella pneumoniae strains (producing KPC-2 and NDM-1), one Klebsiella oxytoca strain producing OXA-48 and one Enterobacter cloacae strain producing NDM-1. The majority of patients had underlying disesases, three were immunocompromised, and three had infections involved the skin and soft tissues. Half patients died as a result of CPE infection.
This study represents the first report of E. coli ST131-O25b clone producing NDM-1 in Latin America. In addition, this study is the first finding of K. oxytoca producing OXA-48 and E. coli producing OXA-232 in Mexican pediatric patients.
Our aim in this report was to describe the characteristics of the first clinical isolate of Escherichia coli (EC-PAG-733) harboring the mcr-1 gene found in Mexico. This isolate was obtained from a ...fecal sample from a young child with an oncological condition. We obtained the whole-genome sequence using next-generation sequencing and analyzed the sequence by bioinformatics tools. EC-PAG-733 was resistant to third- and fourth-generation cephalosporins and was susceptible to all carbapenems and amikacin; it was also resistant to ciprofloxacin, levofloxacin, gentamicin and colistin at a minimum inhibitory concentration (MIC) of 4 μg/mL. This isolate was classified as O11:H25-ST457. EC-PAG-733 harbored an ESBL type CTX-M-55 as well as several virulence factors that have been associated with Enteroaggregative Escherichia coli (EAEC). The mcr-1 gene was located within an IncI2 plasmid. The results of this whole genome shotgun project were deposited in DDBJ/ENA/GenBank under the accession number QKXE00000000.
Highlights • Streptococcus pneumoniae serotype 19A is a frequent pathogen in infants aged ≤60 days. • Serotypes 3, 6A, 10A, 12F, and 15A/B increased after the introduction of heptavalent pneumococcal ...conjugate vaccine (PCV7) in infants aged ≤60 days. • Theoretical serotype coverage among children aged ≤60 days during the period 2000–2014 was 63.5% for PCV13.
Klebsiella pneumoniae (Kpn) strains are a leading cause of hospital-acquired infections, including ventilator-associated pneumonia. Resistance to antibiotics, biofilm formation, and the production of ...certain fimbriae play an important role in the pathogenesis.
We investigated the genetic relatedness, antibiotic resistance, virulence potential, and ability to form biofilms of Kpn strains isolated from hospital-acquired infections (n = 76). Strains were isolated at three major hospitals serving the largest metropolitan urban area in Mexico City, Mexico.
Enterobacterial repetitive intergenic consensus (ERIC)-PCR demonstrated that clonal groups predominate in each hospital. Selected strains chosen from clonal groups (n = 47) were multidrug resistant (MDR, 83%), although the majority (∼70%) were susceptible to carbapenems. All strains produced robust biofilms on abiotic surfaces, and ∼90% harbored adhesin genes fimH, mrkA, and ecpA. The ultrastructure of biofilms was further studied by high-resolution confocal microscopy. The average height of Kpn biofilms on abiotic surfaces was ∼40 μm. We then assessed formation of biofilms on human lung cells, as a surrogate of lung infection. While Kpn strains formed robust biofilms on abiotic surfaces, studies on lung cells revealed attachment to human cells but scarce formation of biofilms. Gene expression studies revealed a differential temporal expression of an adhesin (ecpA) and a capsule (galF) gene when biofilms were formed on different substrates.
Kpn strains isolated from nosocomial infections in Mexico City are MDR, although the majority are still susceptible to carbapenems and form more robust biofilms on polystyrene in comparison to those formed on human cells.
Blood stream infections (BSI) remain a major cause of morbidity and death in patients undergoing cancer treatment. Immediate empiric, broad-spectrum, anti-microbial therapy is the rule for treating ...BSI until the organism and antibiotic sensitivities can be identified. This study seeks to determine the etiology and changes of pattern HAI-BSIs in children with cancer from 2004 to 2012 to determinate changes in empirical therapy strategies.
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