Plasmid Carrying bla_CTX-M-15, bla_PER-1, and bla_TEM-1 Genes in Citrobacter spp. From Regional Hospital in Mexico

Abstract

Introduction: Citrobacter spp. is an opportunistic bacteria that have been recognized as significant pathogens in patients with underlying diseases or immunocompromised status. The aim of this study was to identify extended-spectrum β-lactamases in clinical isolates of Citrobacter spp. Methods: This cross-sectional study was conducted at Hospital Central “Dr. Ignacio Morones Prieto” in San Luis Potosi, Mexico. Nineteen isolates of Citrobacter spp. were obtained from clinical specimens between April to December 2015. Four isolates were resistant to third-generation cephalosporins. The presence of genes encoding ESBL ( blaCTX-M-15, blaTEM-1, blaVEB-1, blaSHV, and blaPER-1) was analyzed by PCR. For this purpose, plasmid DNA was extracted and horizontally transferred to recipient E. coli Top 10. Results: blaCTX-M-15 and blaVEB-1 genes were detected in Citrobacter freundii and Citrobacter sedlakii, whereas blaPER-1 gene was identified in 1 isolate of Citrobacter freundii. In contrast, blaSHV gene was not detected in any isolate. One strain carried blaCTX-M-15, blaTEM-1, blaVEB-1, and blaPER-1 genes, most in a 275-kb plasmid. Conclusion: This study shows the presence of different types of ESBL in clinical isolates of Citrobacter freundii and Citrobacter sedlakii, which confer resistance to broad-spectrum β-lactams. The plasmid identified in this study harboring ESBL genes could play an important role in the dissemination of antibiotic resistance.

Antimicrobial susceptibility of Citrobacter Koseri isolated on clinical samples of hospitalized patients

“…These conditions include sepsis, urinary tract infections, respiratory and intra-abdominal infections, and central nervous system Infections. 1,11,12 C. koseri is a pathogen mostly isolated in urinary samples; 12,13 however, this was not the case of the present study, since it was isolated in more than 50% of pus samples, which classifies it as a pathogen responsible for nosocomial infections.…”

“…They differ because of their ability to convert tryptophan into indole, to ferment lactose and use malonate. 1 The gene Blacko (encodes the chromosomal class A B-lactamase CKO) is only present in C. koseri; therefore, it represents an interesting means to differentiate it from other species of Citrobacter. C. freundii and C. koseri cause most infections by Citrobacter, which have epidemiology and clinical manifestations similar to those of enterobacter infections.…”

“…C. freundii and C. koseri cause most infections by Citrobacter, which have epidemiology and clinical manifestations similar to those of enterobacter infections. 1 The genus Citrobacter is often found in water, food, land and certain animals. It is part of the normal flora of a small proportion of healthy human beings; however, colonization rates increase in patients in long-term care institutions and hospitals, provoking 1 to 2% of nosocomial infections.…”

“…Infections caused by multidrugresistant Citrobacter strains are associated with a higher rate of inhospital mortality compared to those caused by susceptible strains. [1][2][3] C. koseri is an aerobic Gram-negative bacillus, ubiquitous in nature and opportunistic, which is frequently found in genitourinary and gastrointestinal tracts of animals and humans as a saprophyte flora. These microorganisms can produce serious infections, especially in immunocompromised hosts; with greater preference for the central nervous system; they are associated with meningitis, cerebral abscesses, ventriculitis, panophthalmitis and sepsis.…”