VEB-6 extended-spectrum β-lactamase-producing Proteus mirabilis from Sultanate of Oman

Genetics of Acquired Antibiotic Resistance Genes in Proteus spp

Proteus spp. are commensal Enterobacterales of the human digestive tract. At the same time, P. mirabilis is commonly involved in urinary tract infections (UTI). P. mirabilis is naturally resistant to several antibiotics including colistin and shows reduced susceptibility to imipenem. However higher levels of resistance to imipenem commonly occur in P. mirabilis isolates consecutively to the loss of porins, reduced expression of penicillin binding proteins (PBPs) PBP1a, PBP2, or acquisition of several antibiotic resistance genes, including carbapenemase genes. In addition, resistance to non-β-lactams is also frequently reported including molecules used for treating UTI infections (e.g., fluoroquinolones, nitrofurans). Emergence and spread of multidrug resistant P. mirabilis isolates, including those producing ESBLs, AmpC cephalosporinases and carbapenemases, are being more and more frequently reported. This review covers Proteus spp. with a focus on the different genetic mechanisms involved in the acquisition of resistance genes to multiple antibiotic classes turning P. mirabilis into a dreadful pandrug resistant bacteria and resulting in difficult to treat infections.

β-Lactamase production in key gram-negative pathogen isolates from the Arabian Peninsula

SUMMARY Infections due to Gram-negative bacilli (GNB) are a leading cause of morbidity and mortality worldwide. The extent of antibiotic resistance in GNB in countries of the Gulf Cooperation Council (GCC), namely, Saudi Arabia, United Arab Emirates, Kuwait, Qatar, Oman, and Bahrain, has not been previously reviewed. These countries share a high prevalence of extended-spectrum-β-lactamase (ESBL)- and carbapenemase-producing GNB, most of which are associated with nosocomial infections. Well-known and widespread β-lactamases genes (such as those for CTX-M-15, OXA-48, and NDM-1) have found their way into isolates from the GCC states. However, less common and unique enzymes have also been identified. These include PER-7, GES-11, and PME-1. Several potential risk factors unique to the GCC states may have contributed to the emergence and spread of β-lactamases, including the unnecessary use of antibiotics and the large population of migrant workers, particularly from the Indian subcontinent. It is clear that active surveillance of antimicrobial resistance in the GCC states is urgently needed to address regional interventions that can contain the antimicrobial resistance issue.

Characterization and molecular epidemiology of extended spectrum beta-lactamase producing Enterobacter cloacae isolated from a Tunisian hospital

In 2009, out of the 66 nonrepetitive Enterobacter cloacae collected at Charles Nicolle hospital in Tunisia, 44 were extended spectrum β-lactamase (ESBL) producers. The aim of the current study was to detect and characterize the genes encoding the ESBLs including blaTEM, blaSHV, and blaCTX-M groups by polymerase chain reaction and sequencing. Pulsed-field gel electrophoresis (PFGE) analysis was used to determine the genetic relatedness between isolates. All strains were susceptible to carbapenems. They were resistant to fluoroquinolones, gentamicin, tobramycin, and trimethoprim+sulfamethoxazole but variably resistant to netilmicin, amikacin, and tetracyclines. Sequence analysis of the polymerase chain reaction products revealed the presence of blaCTX-M-15 (39 strains), blaSHV-12 (6 strains), and blaSHV-27 (1 strain). The coexistence of two ESBLs was observed in two isolates harboring, respectively, SHV-12+CTX-M-15 and SHV-27+CTX-M-15. PFGE revealed 36 unrelated profiles. Diffusion of E. cloacae producing CTX-M-15 ESBL in our hospital is the consequence of dissemination of identical or related plasmids harboring the CTX-M-15 gene.