Antibacterial susceptibility patterns and cross-resistance of methicillin resistant and sensitive Staphyloccus aureus isolated from the hospitalized patients in Shiraz, Iran

Abstract

Nosocomial infections caused by methicillin-resistant staphylococci (MRSA) pose a serious problem in many countries. This study aimed to determine the antibacterial susceptibility patterns of methicillin sensitive and resistant Staphylococcus aureus isolates from the hospitalized patients. Totally 356 isolates of Staphylococcus aureus (S. aureus) including 200, 137 and 19 corresponding to MSSA, MRSA, and intermediate MRSA strains, respectively were isolated. Antibacterial susceptibility patterns of the isolates to 14 antibiotics were examined using Kirby-Bauer method. MICs of 15 antibiotics to 156 MRSA isolates were determined by E test method. Cross-resistances of MRSA isolates (137+19) to the other tested antibiotics were also determined. S.aureus with high frequencies were isolated from the blood, sputum and deep wound samples. All of 200 MSSA isolates were sensitive to oxacillin, vancomycin, tecoplanin, rifampin, linezolid, quinupristin/dalfopristin, mupirocin and fusidic acid. A gradient of reduced susceptibility of MSSA to cephalexin, co-trimoxazole, ciprofloxacin, clindamycin, tetracycline, erythromycin and gentamicin were evident. MRSA isolates were sensitive to vancomycin, tecoplanin, linezolid, quinupristin/dalfopristin, mupirocin and fusidic acid, while reduced susceptibility of them to rifampin, co-trimoxazole, clindamycin, cephalexin, tetracycline, ciprofloxacin, erythromycin and gentamicin were observed. MRSA isolates exhibited a high range of cross-resistance to the eight tested antibiotics. Overall, co-trimoxazole, ciprofloxacin, clindamycin, tetracycline, erythromycin and gentamicin showed low activity against MSSA and MRSA isolates which may indicate they are not suitable to be used in clinical practices. To preserve the effectiveness of antibiotics, rational prescription and concomitant application of preventive measures against the spread of MRSA are recommended.

Antibiotic resistance rates of Pseudomonas aeruginosa, Acinetobacter baumannii and Klebsiella pneumoniae isolated from a university-affiliated hospital in North Cyprus

“…In a recent metaanalysis from Turkey, P. aeruginosa isolates were In our study, A. baumannii isolates exhibited high resistance (32.8%-92.7%) against most of the antimicrobial agents tested (Table 3). This finding is consistent with those of many other studies where A. baumannii was shown to develop resistance to most of the antibiotics (23)(24)(25)(26)(27). In this study, the lowest resistance rates in A. baumannii isolates were detected for colistin (5.1%) and ampicillinsulbactam (13.1%) ( Table 3).…”

Characterization of carbapenem-resistant Acinetobacter calcoaceticus–baumannii complex isolates from nosocomial bloodstream infections in southern Iran

“…In this study, a high rate of carbapenem resistance was found (61 out of 78). As reports from the present study hospital show, there has been a dramatic increase in the resistance to cabapenems for A. baumannii isolates, from 23 % in -2008(Japoni et al, 2011 to 78.2 % in 2012 (the present study) and 85.3 % in 2013-2014 (unpublished data). A worldwide study between 2005 and 2009, from 140 hospitals in 32 countries, revealed the overall non-susceptibility rate to imipenem and meropenem to be 45.9 and 48.2 %, respectively (Mendes et al, 2010).…”

Prevalence of methicillin-resistant Staphylococcus aureus in a University Hospital in the South of Brazil

“…In the USA and in some European countries, the incidence of bacteremia caused by MRSA has increased in the last years (Shorr, Lodise, 2006). According to a study carried out in Iran, in 2007, Japoni et al (2010) reported a bigger number of MRSA isolates in blood, sputum and wound samples while Mahmood et al (2010) reported a bigger incidence in sputum samples. In Brazil, Souza, Figueiredo (2008) in 2008, at the Regional University Hospital of Maringá found a bigger incidence of MRSA isolates in catheter tips and tracheal secretion.…”

“…MRSA are the main responsible agents, which cause nosocomial infections all over the world (Japoni et al, 2010). In Brazil, the MRSA prevalence varies according to the regions and to the clinical material from which this important pathogen is isolated, presenting rates between 44% to 56% (Ferreira et al, 2009;Carvalho, Mamizuka, Gontijo Filho, 2010).…”