Patterns of Multidrug Resistance among Methicillin-Resistant Hospital Isolates of Coagulase-Positive and Coagulase-Negative Staphylococci Collected in the International Multicenter Study RESIST in 1997 and 1998

Abstract

The primary purpose of the multicenter international study "RESIST" was to obtain an update on the degree of multidrug resistance among methicillin-resistant staphylococci collected from a geographically diverse sample. A total of 3,307 staphylococcal isolates were recovered from single patients and primarily from clinical specimens that were collected at 20 collaborating regional health centers located in several countries in Europe, Asia, and Latin America during a 3- to 4-month period each in 1997 and 1998. All strains were deposited at the Laboratory of Molecular Genetics at ITQB/UNL in Oeiras, Portugal, for quality control and for testing by microbiological and molecular typing techniques; the Laboratory of Microbiology at The Rockefeller University serving as organizational center. The majority of strains, 3,100, were methicillin-resistant, of which 1,749 were coagulase positive (methicillin-resistant Staphylococcus aureus, MRSA), and 1,351 were coagulase negative (methicillin-resistant coagulase negative staphylococci, MRCNS). The overall frequency of drug resistance traits among the 1,749 MRSA strains was high (over 70% and up to and over 90% of the strains) to ciprofloxacin, erythromycin, clindamycin, gentamicin, and tetracycline, and was somewhat less frequent to sulfamethoxazole-trimethoprim (45%), chloramphenicol (30%), and rifampin (38%). None of the 3,307 staphylococcal isolates showed reduced susceptibility to vancomycin except for a single methicillin-resistant coagulase-negative isolate. The great majority of staphylococci were also susceptible to the new antimicrobial Synercid. In contrast, resistance to teicoplanin was significant among methicillin-resistant strains of coagulase-negative staphylococci, particularly among Staphylococcus haemolyticus. MRSA isolates showed marked geographic variation in their patterns of multiresistance, most likely reflecting the properties of unique multiresistant MRSA clones dominant in the hospitals that provided the MRSA isolates from the various geographic areas. The multiresistance patterns of MRSA strains and strains of methicillin-resistant coagulase-negative staphylococci originating at the same country source also showed striking differences, suggesting that resistance to antimicrobial agents emerged under different antibiotic pressures in these bacterial species.

Molecular Characterization of Staphylococcus Epidermidis Isolates Recovered from Patients Admitted to a Referral Hospital in Iran

“…These findings are consistent with other studies (20). Discussions regarding CoNS in blood cultures and hospital infections in numerous European and Asian countries have demonstrated that resistance to aminoglycosides and trimethoprim/sulfamethoxazole has increased in past two decades (20,21). Increase of MDR strains and the importance of functional molecular typing methods in comparison to conventional techniques has motivated us to conduct the present study.…”

Prevalence and Anti-Microbial Susceptibility of Methicillin Resistant <i>Staphylococcus aureus</i> at Moi Teaching and Referral Hospital Eldoret

“…This figure is however way below the Japanese prevalence of 72% but much higher than the prevalence levels of North Europe where low figures of 1% have been recorded in Norway, Sweden and Holland [19]. The study has also shown that the MRSA is multi-drug resistant, a trend which has been demonstrated by other studies around the world [20]- [22]. There was significant resistance to anti-microbials that have been the bedrock of therapy in this country including gentamycin, tetracycline, ciprofloxacin, and erythromycin.…”

Urban ants and transportation of nosocomial bacteria

“…With its high virulence, it is able to become resistant to antimicrobials , Marin 2002). Among the coagulasenegative staphylococci, the methycillin resistant strains stand out for their frequent involvement in infections associated with foreign bodies and represent major resistance gene pools (Sanches et al 2000), as observed in S. epidermidis, S. hemolyticus, S. capitis, S. chromogenes, S. cohnii, S. equorum, S. felis, S. hominis, S. lentus, S. simulans, S. warneri and S. xylosus (Becker et al 2001).…”