No abstract

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections among young people without healthcare-associated risk factors have emerged during the past decade. Reported prevalence rates of CA-MRSA vary widely among studies, largely because of the different definitions employed and different settings in which the studies have been performed. Although the majority of CA-MRSA infections are mild skin and soft tissue infections, severe life-threatening cases have been reported. CA-MRSA infections have mostly been associated with staphylococcal strains bearing the staphylococcal cassette chromosome mec type IV element and Panton-Valentine leukocidin genes. These strains are more frequently susceptible to a variety of non-beta-lactam antibiotics. Clinicians must be aware of the wide spectrum of disease caused by CA-MRSA. Continued emergence of MRSA in the community is a public health problem, and therefore warrants increased vigilance in the diagnosis and management of suspected and confirmed staphylococcal infections.

No abstract

To determine changes in the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA), a prospective study was conducted for a 30-month period in a university hospital in the eastern province of Saudi Arabia. Of 1,096 Staphylococcus aureus isolates identified, 92 (8.4%) were MRSA. Seventy-two (78%) of the 92 isolates were from nosocomial cases and 20 (22%) isolates were from community cases. Thirteen (14%) of 20 patients with community-acquired MRSA had no discernible risk factors. The community-acquired MRSA from patients without identified risk were susceptible to a greater number of antimicrobials compared with isolates obtained from patients with community-acquired MRSA with identified risk or with nosocomially acquired MRSA. No strain resistant to vancomycin was recorded in this study. The impact of these organisms could be substantial if they become more frequent or widespread.

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...