Quinolones : de l’antibiogramme aux phénotypes de résistance

Antibiogram Profile of Acinetobacterbaumannii Recovered from Selected Freshwater Resources in the Eastern Cape Province, South Africa

Acinetobacter species have been found in a variety of environments, including soil, food, plants, hospital environments and water. Acinetobacter baumannii is an opportunistic and emerging waterborne pathogen. It has been implicated in several nosocomial infections that demonstrate resistance to commonly administered antibiotics. We investigated phenotypic antibiotic resistance (PAR) and relevant antibiotic resistance genes (ARGs) in A. baumannii isolated from three freshwater resources in the Eastern Cape Province, South Africa; A. baumannii (410) was confirmed by the recA and gyrB genes of 844 suspected Acinetobacter species in the water samples. The PAR of the confirmed isolates was assessed using a panel of 11 antibiotics by the disc diffusion method, while ARGs were investigated in isolates exhibiting PAR. The A. baumannii isolates were resistant to piperacillin-tazobactam (11.2%), ceftazidime (12%), cefotaxime (18.8%), cefepime (8.8%), imipenem (2.7%), meropenem (4.15%), amikacin (2.4%), gentamicin (8.8%), tetracycline (16.8%), ciprofloxacin (11%) and trimethoprim/sulfamethoxazole (20.5%). For multidrug resistance (MDR), two isolates were resistant to all antibiotics and 28 isolates were resistant to imipenem and meropenem. Moreover, β-lactamases bla_TEM (64.4%) and bla_OXA-51 (28.70%) as well as sulphonamides sul1 (37.1%) and sul2 (49.4%) were common ARGs. Overall, PAR and ARGs had positive correlations (r) in all rivers. Detection of MDR-A. baumannii in freshwater resources could be linked to possible wastewater discharge from the nearby animal farms, indicating potential implications for public health.

Molecular mechanisms of antimicrobial resistance in Acinetobacter baumannii, with a special focus on its epidemiology in Lebanon

Acinetobacter baumannii is an opportunistic bacterium involved in several types of infection with high mortality and morbidity, especially in intensive care units. Treatment of these infections remains a challenge due to the worldwide emergence of broad-spectrum resistance to many antibiotics. Following the implementation of molecular techniques to study A. baumannii outbreaks, it has been shown that they are mainly caused by specific clones such as international clones I, II and III. The present work aims to review the available data on the mechanisms underlying antimicrobial resistance in A. baumannii, with a special focus on the molecular epidemiology of this species in Lebanon.