Oxacillinases and antimicrobial susceptibility of Ralstonia pickettii from pharmaceutical water systems in Croatia

Abstract

This study evaluated antibiotic susceptibility and presence of blaOXA22 and blaOXA60 genes in 81 isolates of Ralstonia pickettii obtained from different purified and ultra‐pure water systems in two different geographical areas of Croatia. E‐test and disc diffusion test were performed to determine antibiotic susceptibility. Polymerase chain reaction was applied to detect genes encoding OXA‐22 and OXA‐60 oxacillinases previously identified in R. pickettii. The isolates were genotyped by pulsed‐field gel electrophoresis. The results revealed variable susceptibility/resistance profiles. Our isolates exhibited high susceptibility rates to ceftriaxone, cefotaxime, piperacillin‐tazobactam, ciprofloxacin, imipenem, cefepime and in lesser extent to ceftazidime. High rates of susceptibility were also observed for sulphamethoxazole‐trimethoprim and piperacillin. High resistance rates were noticed for ticarcillin‐clavulanate, aztreonam and meropenem, as well as for all aminoglycosides tested. Modified Hodge test was positive in 51·9% strains, indicating production of carbapenemases. blaOXA22 and blaOXA60 genes were detected in 37·0 and 80·3% strains, respectively. Pulsed‐field gel electrophoresis identified three major clusters containing subclusters. R. pickettii should be taken seriously as a possible cause of nosocomial infections to ensure adequate therapy, to prevent the development of resistant strains and to try to reduce the possibility of R. pickettii surviving in clean and ultra clean water systems.

Persistent bacteremia caused by Ralstonia pickettii and Microbacterium: a case report

“…Our isolated strain was resistant to tobramycin; this finding was consistent with the results of Yan Tao et al [ 1 ], but inconsistent with those reported by Monica Basso et al [ 4 ]. Moreover, our isolated strain was resistant to meropenem; this observation differed from the results reported in the literature, except for the study of Monica Basso et al Differences were also found in sensitivity to other antibiotics, particularly carbapenems and aminoglycosides, which might be due to the presence of two inducible β-lactamases, namely blaOXA-22 and blaOXA-60 [ 14 ]. The existence of these beta lactamases require further studies to verify in the isolated strain.…”

Bloodstream Infections Caused by Drug Resistant Ralstonia species: A Case Series During the COVID-19 Pandemic

“…Additionally, it is capable of producing the chromosomal beta-lactamase OXA-60 that hydrolyzes imipenem. 16,17 OXA-22 and OXA-60 beta lactamases have been recently reported in environmental strains of Ralstonia. 17 To our knowledge, this is the first 2).…”

“…16,17 OXA-22 and OXA-60 beta lactamases have been recently reported in environmental strains of Ralstonia. 17 To our knowledge, this is the first 2). This can impose a pending threat of hospital associated infections by the organism that are hard to treat since Ralstonia spp.…”