Toxins and Antibiotic Resistance in Staphylococcus aureus Isolated from a Major Hospital in Lebanon

Abstract

Molecular characterization of Staphylococcus aureus is of both clinical and infection control importance. Virulence determinants using PCR and multiple drug resistance profiles were studied in 130 S. aureus isolates. PCR-RFLP analysis of the 16S-23S DNA spacer region was done to investigate the level of 16S-23S ITS (internal transcribed spacer) polymorphism. Methicillin-resistant S. aureus (MRSA), which represented 72% of the studied isolates, showed multiple drug resistance with 18% being resistant to 10-18 of the drugs used compared to a maximum resistance to 9 antibiotics with the methicillin sensitive S. aureus (MSSA) isolates. Exfoliative toxin A (ETA) was more prevalent than B (ETB) with virulent determinants being additionally detected in multiple drug-resistant isolates. 16S-23S ITS PCR-RFLP combined with sequencing of the primary product was successful in generating molecular fingerprints of S. aureus and could be used for preliminary typing. This is the first study to demonstrate the incidence of virulent genes, ACME, and genetic diversity of S. aureus isolates in Lebanon. The data presented here epitomize a starting point defining the major genetic populations of both MRSA and MSSA in Lebanon and provide a basis for clinical epidemiological studies.

Association of tsst-1 and pvl with mecA Genes among Clinical Staphylococcus aureus Isolates from a Tertiary Care Hospital

“…Other studies have also reported that up to 58% of MRSA strains were tsst-1 gene positive 33,36,37 . Similar to our findings, the prevalence of tsst-1 gene was reported up to 56% among the MSSA isolates in other studies [24][25][26]38 .…”

Meticillin-resistant Staphylococcus aureus isolated from Iranian hospitals: virulence factors and antibiotic resistance properties

“…We also found statistically signifi cant (p<0.05) association between the levels of resistances to penicillin, cefalotin, cefazoline, and ceftriaxone with mupirocin, rifampicin, trimethoprim, imipenem and gentamicin antibiotics. Tokajian et al [2] reported that 72 of S. aureus isolates of Lebanon' s hospitals were meticillin-resistant and 18 of them were resistant to 10-18 antibiotics. Study of Udo et al [4] showed that 1,765 (95.6) inpatients and 81 (4.4) outpatients of Kuwait hospitals were positive for S. aureus with 32 incidence rate of the meticillin resistant strains.…”

“…Th e bacterium can colonize individuals both in the community and hospital settings [1]. Infections caused by this bacterium are treated mainly with meticillin but in recent years, increasing numbers of meticillin resistant S. aureus (MRSA) strains have been reported worldwide from patients with community-acquired infections [2][3][4]. Globally, fi fteen to forty fi ve percent of S. aureus strains isolated from hospital infections were meticillin resistant [5,6].…”

Detection and Antimicrobial Resistance Properties of Staphylococcus aureus Strains Isolated from the Human Clinical Infections

“…High prevalence of MRSA in various types of clinical infections were also reported by Alghaithy et al, (2000) (61% in Saudi-Arabia) 26 , M³ynarczyk et al, (2001) (40% in Warszawie) 27 and Rijal et al, (2008) (56.1% in Pokhara) (28). Virdis et al, (2010) 29 showed that the prevalence of resistance of S. aureus against kanamycin, oxytetracycline and ampicillin were 28%, 16% and 12%, respectively. Deng et al, (2013) 30 reported that the high prevalence of resistance of the S. aureus against most commonly used antibiotics including naficillin, oxacillin, vancomycin and cefathiamidine.…”

“…It has been documented that majority of S. aureus strains were resistant to sulfamethoxazole-trimethoprim, erythromycin, oxacillin, ampicillin, penicillin, tetracycline, chloramphenicol, cotrimoxazole, gentamicin, cefexim and clindamycin 7,8 . In recent years prevalence of resistance against methicillin and vancomycine has been increased throughout the world [9][10][11][12][13] .…”