Prevalence of digestive tract colonization of carbapenem-resistant Acinetobacter baumannii in hospitals in Saudi Arabia

Abstract

Carbapenem-resistant Acinetobacter baumannii is a major health problem worldwide, especially in intensive care units (ICUs). This study aimed to detect the prevalence of A. baumannii colonization of the gastrointestinal tract of patients admitted to the ICU in two hospitals in Saudi Arabia. In addition, it aimed to characterize the molecular mechanisms of carbapenem resistance in these isolates. From January to June 2014, 565 rectal swab specimens were screened for Acinetobacer strains and carbapenem resistance using CHROMagar Acinetobacter and CHROMagar KPC agar plates, respectively. Organism identification and susceptibility were detected using the Vitek 2 system. A total of 47 Acinetobacter spp. were detected, and 35 were resistant to carbapenem, making the prevalence of Acinetobacter spp. 8.3 % (47/565) and carbapenem resistance (6.2 %, 35/565). The 47 strains showed remarkable clonal diversity as revealed by PFGE. Using PCR, OXA-51, a chromosomal marker for A. baumannii, was detected in 46 strains. OXA-23 b-lactamase was detected in all 35 carbapenem-resistant A. baumannii. No IMP, VIM, SPM, SIM, GIM, KPC or NDM b-lactamases were detected in these isolates. Thus, OXA-23 was the main mechanism of carbapenem resistance in these isolates. To the best of our knowledge, this is the first study to detect the prevalence of Acinetobacter colonization in the digestive tract of ICU patients in Saudi Arabia. This study revealed the importance of having wellestablished protocols for early identification of these multidrug-resistant organisms, optimizing infection-control strategies and having active surveillance studies to reduce morbidity, mortality and cost. INTRODUCTIONAcinetobacter baumannii has emerged as a leading cause of nosocomial infections, especially in intensive care units (ICUs), causing a variety of infections including septicaemia, urinary tract infections and wound infections (Maragakis & Perl, 2008;Peleg et al., 2008;Poirel & Nordmann, 2006). It is a leading cause of ventilator-associated pneumonia worldwide (Maragakis & Perl, 2008;Mugnier et al., 2008;Peleg et al., 2008). From 2005 to 2009, A. baumannii caused approximately 26.5 % of ventilator-associated pneumonia in Riyadh, Saudi Arabia (El-Saed et al., 2013). The prevalence of carbapenem-resistant A. baumannii (CRAB) has increased worldwide including countries of the Gulf Cooperation Council such as Kuwait, Saudi Arabia and Bahrain (Abdalhamid et al., 2014;Al-Sweih et al., 2012;Alsultan et al., 2014; ElSaed et al., 2013;Khan et al., 2012;Mugnier et al., 2008).Carbapenem resistance in A. baumannii is due mainly to the production of carbapenem-hydrolysing enzymes, carbapenemases (Maragakis & Perl, 2008;Peleg et al., 2008;Poirel & Nordmann, 2006 The aim of this study was to evaluate the prevalence of colonization and carbapenem resistance in Acinetobacter spp. isolated from the intestinal microbiota of ICU patients at two hospitals in the Eastern Province of Saudi Arabia. In addition, we also aimed to characterize the molecular mechanisms of carbapen...

Rates of gastrointestinal tract colonization of carbapenem-resistant Enterobacteriaceae and Pseudomonas aeruginosa in hospitals in Saudi Arabia

“…The treatment of these organisms became more difficult because of their production of extended-spectrum β-lactamases (ESBLs), such as bla CTX-M , plasmid-mediated AmpC (pAmpC) or overexpression of chromosomal amp C gene [6] , [7] , [8] , [9] , [10] . Carbapenems became the last source for treatment of such organisms, which in turn has led to the emergence of carbapenem resistance under antibiotic selective pressure [8] , [11] , [12] . The global spread of carbapenem-resistant, Gram-negative rods is significantly increasing [1] , [2] , [13] .…”

“…Carbapenem resistance in Gram-negative rods is mainly due to two mechanisms: first the production of carbapenem-hydrolyzing enzymes (i.e. serine-carbapenemases and metallo-β-lactamases), and second the combination of membrane impermeability with production of ESBLs, pAmpC or amp C overexpression [2] , [8] , [11] , [13] . Carbapenem-hydrolyzing enzymes is the most alarming mechanism because genes encoding carbapenem resistance (i.e.…”

“…Therefore, they are transmissible from one organism to another, thus creating a major infection control concern worldwide [8] , [14] , [15] . Generally carbapenem resistance is associated with resistance to other antibiotics such as aminoglycosides and fluoroquinolones in these organisms [11] , [15] .…”

“…In order to control their spread, good surveillance and infection control programmes must be established to identify the digestive colonization of these carbapenem-resistant organisms. There are scanty data in the literature characterizing the gastrointestinal colonization of these organisms [11] , [21] . In a previous study, our group found that the prevalence of digestive tract colonization of carbapenem-resistant Acinetobacter baumannii was 6.2% [11] .…”

Nanomaterials for alternative antibacterial therapy

“…12 The hospital-acquired infections manifest in a wide gamut of severe clinical ramifications, such as bacteremia, septic shock, ventilator-related pneumonia and massive soft tissue necrosis, and rapidly progress to systemic infections that eventually culminate in multiorgan failure and death. 13 The control measures including implementation of hygiene, patient isolation and environmental decontamination have proved ineffective in keeping the infection at bay.…”