Resistance to Beta-lactams by Klebsiella Co-Producing Resistance Enzymes at the Pietro Annigoni Research Centre (CERBA)

The misuse of antibiotics promotes the development of multi-resistance in bacteria both biochemically and genetically, as well as its ability to transmit to other bacteria. These microorganisms are capable of simultaneously producing resistance enzymes through resistance mechanisms that allow them to resist various classes of antibiotics at the same time and thus become multi-resistant. Our objective was to study resistance to beta-lactams by Klebsiella co-producing resistance enzymes isolated at the Pietro Annigoni Research Center (CERBA). The isolation and purification of bacterial strains isolated from stools, vaginal swabs and urine of internal and external patients of CERBA, were carried out on selective media and Muller Hinton (MH). The antibiogram was carried out according to the disk diffusion method. The API 20E biochemical gallery (Bio Mérieux, France) was used for the identification of enterobacteria and the <i>bla</i><sub>NDM</sub>, <i>bla</i><sub>SHV</sub> and <i>bla</i><sub>TOHO</sub> genes were detected by conventional Polymerase Chain Reaction (PCR). A total of one hundred and twenty-two (122) strains of Gram-negative bacilli were collected and identified. Among them we have 23.77% (29/122) strains of <i>Klebsiella </i>including 86.21%<i> </i>isolated from urine, 6.90% isolated from stool and 6.90% isolated from vaginal swab. The antibiogram showed that all 29 <i>Klebsiella strains </i>were resistant to at least one of the beta-lactams studied, including 93.10% resistance to amoxicillin plus clavulanic acid, 37.93% resistance to ceftazidime, 27.59% resistance to ceftriaxone, 44.83% to cefotaxime, 20.70% to imipenem and 24.14% to aztreonam. Among the 29 <i>Klebsiella </i>strains 24.13% were non-carriers of resistance genes and 76.86% of the strains were carriers of at least one of the resistance genes. However, 62.06% of <i>Klebsiella </i>strains harbor the bla <i><sub>SHV</sub></i><i> </i>gene, 41.38% of strains harbored <i>bla</i><sub>NDM</sub> versus 10.34% of strains carrying the <i>bla </i><sub>TOHO</sub> gene. Among the <i>Klebsiella </i>strains, 37.93% of the strains had coexistences of the genes, <i>bla</i><sub>SHV</sub> + <i>bla</i><sub>NDM</sub>, <i>bla</i><sub>SHV</sub> + <i>bla</i><sub>TOHO</sub> and <i>bla</i><sub>TOHO</sub> + <i>bla</i><sub>NDM</sub> respectively. However, the <i>bla</i><sub>SHV</sub> gene was most common in Klebsiella (<i>Klebsiella sp </i>and <i>Klebsiella pneumoniae), followed by the bla </i><sub>NDM</sub> gene<i> and the bla </i><sub>TOHO</sub> gene. This study has highlighted the multi-resistance of <i>Klebsiella strains </i>co-producing ESBLs of <i>the bla</i><sub>NDM</sub>, <i>bla</i><sub>SHV</sub> and <i>bla</i><sub>TOHO</sub> type. The co-production of genes by certain strains, particularly <i>Klebsiella </i>strains, requires the development of new strategies in scientific research in order to find effective therapeutic solutions to destroy multi-resistant bacteria.