ABSTRACT
Background: Acinetobacterbaumannii became one of the emerging life-threatening hospital acquired infection pathogens with marked antibiotic resistance due to multiple resistance mechanisms. One of these mechanisms is production of carbapenemase enzymes like Ambler Class B and Class D enzymes that hydrolyze carbapenems the last resort antimicrobial drug for treating multidrug resistant organisms
Objectives: To study the antimicrobial resistance of A. baumannii with detection of blaOXAcarbapenemase genes responsible for resistance to carbapenems. Also to evaluate effectiveness of newly issued commercial RapidecCarba NP kit test for detection of carbapenemases production and to assess the effect of implementing infection prevention and control [IPC] practices in decreasing rate of ICU blood stream infections
Methodology: This study was conducted from May 2017 to September 2018 by collecting blood cultures from ICU patients. A. baumannii species were identified and antibiotic susceptibility was run by VITEK 2Compact automated ID/AST instrument. Carbapenemase production was tested phenotypically by using RapidecCarba NP kit test. A. baumannii species were tested for carbapenemase genes blaOXA-51, blaOXA-23, blaOXA-24 and blaOXA-58by multiplex PCR
Results: there was a significant decrease in number of ICU blood stream infections after implementing IPC practices. Isolated A. baumannii species were 100 % resistant to Ampicillin/Sulbactam, Cefipime, Ceftriaxone, Imipenem and Trimethoprim/Sulphamethoxazole, while highest sensitivity was to Amikacin [27.4 %]. All isolates A. baumannii species gave positive results with RapidecCarba NP kit test. Only blaOXA-23 [82.4 %] andblaOXA-51 [88.2 %] were detected in isolated A. baumannii species but blaOXA-24 andblaOXA-58 were not detected
Conclusion: A. baumannii is a great life-threatening hospital acquired pathogen with marked drug resistant and easy spread. RapidecCarba NP kit test is an easy, non-labor phenotypic test for carbapenemases production detection which can replace old cumbersome, difficult and labor Carba NP test
ABSTRACT
Non-fermenting gram negative bacilli including Pseudomonas aernginosa, Stenotrophomonas maltophilia and Acinetobacter spp. have been implicated in a variety of nosocomial infection particularly in Intensive Car Units [ICUs]. This study aimed to overview the problem of multidrug resistant Pseudomonas spp an Acinetobacter spp causing nosocomial infections in ICUs in National Liver Institute and to determine the risk factors predisposing to these infections, also to assess the occurrence of ES beta ls and M beta Ls among these isolates. The study included 160 nosocomially infected patients [97 males and 63 females]. Also,20 hospital staff who were in close contact to ICU patients and 40 environment and equipment samples from the ICU. Bacterial culture and identification were carried out using standard microbiological methods. The antibiotic susceptibility was tested using the disc diffusion methods, also gram negative isolates were tested for ES beta Ls and M beta L production by disk diffusion method, double disk synergy test and E test [for MBL]. Our results revealed that NF gram negative isolates represented 18.75% of nosocomial isolates. Pseudomonas spp was 15.6%, Acinetobacter spp was 2.1% and Stenotrophomonas maltophilia was 1.04%. They were frequently isolated from cases with ventilator associated pneumonia [VAP]. All isolates were resistant to ampicillin and augmentin, They were highly sensitive to gentamycin [Pseudomonas spp 80.6%, Acinetobacter spp 80% and S. maltophilia 100%]. They were highly resistant to ceftriaxone [Pseudomonas spp 77.8%, Acinetobacter spp 80% and S.maltophilia 50%], ceftazidime[Pseudomonas spp 80.6%, Acinetobacter spp 100% and S.maltophilia 100%], Rates of resistant to Imipenem were[Pseudomonas spp 61.1%, Acinetobacter spp 80% and S.maltophilia 50%]. ES beta L +ve Pseudomonas spp. and Acinetobacter spp. detected by disk diffusion method were 38.9% and 40% respectively, and confirmed by double disk synergy tests were 25% and 40% respectively. M beta L was produced by 61.1% of Pseudomonas isolates and 80% of Acinetobacter isolates detected by disk diffusion and DDT, while E test detected the presence of M beta L in 52.8% of Pseudomonas isolates and 60% of Acinetobacter isolates. In conclusion non-fermenting Gram-negative bacilli including Pseudomonas spp, Acinetobacter spp and Stenotrophamoneas maltophilia were important causes of nosocomial infections in ICUs,particularly VAP. Most of these isolates were multidrug resistant and producers of ES beta L and M beta L