Molecular characterisation of a dominant methicillin-resistant Staphylococcus aureus (MRSA) clone in a Mexican hospital (1999-2003).

Methicillin-resistant Staphylococcus aureus (MRSA) isolates (n = 216), collected between January 1999 and May 2003 in a tertiary-care university hospital in Guadalajara, Mexico, were characterised by antibiotype, pulsed-field gel electrophoresis (PFGE) of SmaI macrorestriction fragments, and hybridisation of ClaI digests with mecA- and Tn554-specific DNA probes. Representatives of the single clonal type found were analysed by spa typing, multilocus sequence typing and staphylococcal chromosomal cassette mec (SCCmec) typing, and were tested for the presence of 22 virulence determinants and agr type. A single PFGE pattern was identified, with minor variations over time, with spa type 2, sequence type 5, SCCmec type II, agr type 2 and the presence of the enterotoxin genes seg and sei, the gamma-haemolysin variant gene hlg-v and the leukocidin lukE-lukD genes. In addition, the isolates showed antimicrobial resistance to beta-lactams, macrolides, chloramphenicol and imipenem, and susceptibility to gentamicin, rifampicin, trimethoprim-sulphamethoxazole and vancomycin. Following its appearance in 1997, this clone spread within the hospital, and is now present in most of the hospital units and wards.

In vitro activity of several antimicrobial agents against genital mycoplasmas.

The increasing resistance of genital mycoplasmas to tetracyclines is a serious problem, since this group of antibiotics is one of the few that is effective against virtually all species of mycoplasmas. Tetracyclines are also used to treat many sexually transmitted diseases. In this study, we assessed the susceptibility of Mycoplasma hominis and Ureaplasma urealyticum to macrolides, tetracyclines, spectinomycin, and trospectomycin by the agar dilution method. For M hominis, trospectomycin was the most active agent. Spectinomycin, tetracycline, and doxycycline had comparable mycoplasmatic activity, and the macrolides were ineffective. Against U urealyticum, spectinomycin and trospectomycin were the most active drugs, and were at least twofold more active than the macrolides and tetracyclines.

[Prevalence of cervicovaginal infections caused by Chlamydia trachomatis among female population of the city of Cuernavaca, Morelos]. / Prevalencia de infección cervicovaginal por Chlamydia trachomatis en población femenina de la ciudad de Cuernavaca, Morelos.

The chlamydiae are a genetically diverse group of bacteria with a unique intracellular development cycle. The spectrum of clinical manifestations of Chlamydia trachomatis infections in the female includes cervicitis, acute urethral syndrome, pelvic inflammatory disease, salpingitis and the risk of exposure of infants born through an infected birth canal who may develop inclusion conjunctivitis and/or pneumonia. In order to determine the prevalence of cervicovaginal infections caused by C. trachomatis in female population in Cuernavaca, Morelos, we studied 2,407 sexually active women from a suburban area. Genital specimens were collected from each woman and cultured in McCoy cell monolayers. Detection of the bacteria was done by staining with fluorescein-conjugated monoclonal antibodies (Syva Microtrak, Palo Alto CA). 97 of them were culture-positive for C. trachomatis, with and overall prevalence of 4.02 per cent. The most important clinical symptom observed in 47 of the infected patients was an increased or altered vaginal discharge.