Abstract
As very little information is known of the antibiotic resistance in Gram-negative bacteria in Libya in addition to the desperate need for insight
knowledge of the antibiotic resistance in Libyan hospitals, this study was
undertaken to investigate the mechanism of antibiotic resistance in isolates
collected from clinical, non-clinical and environmental samples from Tripoli
and Benghazi, Libya. Bacterial collection include samples taken from patients
admitted to the hospitals in ICUs and other wards, they also include swabs
randomly collected from hospitals environment. These swabs were from walls,
bedsides, curtains, floors, toilets, workstations, mechanical ventilators,
stainless steel containers and instruments used in particular ICUs. This study
clearly demonstrates the emergence of MDR Gram-negative bacteria in
Tripoli and Benghazi hospitals, these MDR bacteria were clinical and nonclinical revealing the long standing infection control problem in these
hospitals. K. pneumoniae was found as the most frequently isolated strain
being disseminated in hospitals and outside hospitals followed by E. coli. K.
pneumoniae and E. coli were detected harbouring blactx-m group 1 in
association with ISEcpl the enhancer of the p-lactamase gene movement.
More importantly, ^/«ctx-m-is in association with ISEcpl were detected carried
on conjugative plasmids of different sizes and able to move via Libyan K.
pneumoniae and E. coli to sensitive bacteria via conjugation. Some isolates of
K. pneumoniae were clonally related and were in some cases found in
different hospital revealing the outbreak of MDR K. pneumoniae in Libyan
hospitals. E. coli strains showed the emergence of more than one clone in one
hospital which indicates to the lack of hospital hygiene. Three novel sequence
types among K. pneumoniae were discovered in this study, one of which K.
pneumoniae AES817 that assigned ST511 was collected from one of Benghazi
streets and was found carrying blacrx-M-15 and ISEcpl on a plasmid of 400kb.
Characterisation of P. aeruginosa showed the emergence of clonally related
strains carrying blaym-2, one was isolated from a patient admitted to Al-Jalla
hospital in Benghazi and the other from a stainless steel container from the
same hospital but different ward, this MBL was found on a novel integron in
both strains. Interestingly, 6 /