[Streptococcus pyogenes: in vitro susceptibility and role of beta-lactamase producing bacteria in the persistence of streptococcal pharyngotonsillitis]. / Streptococcus pyogenes: susceptibilidad in vitro y papel de las bacterias productoras de betalactamasa en la persistencia de la faringoamigdalitis estreptocócica.

OBJECTIVE: To assess the frequency of association between Streptococcus pyogenes and beta-lactamase-producing-bacteria in the pharyngotonsillitis and the evaluate the in vitro susceptibility. DESIGN: Prospective, descriptive, transverse study. SETTING: The present study was carried out in the Health Center Dr. José Castro Villagrana, in Tlalpan, México, D.F., from Juanary, 1996 to February 1999. PARTICIPANTS: In three hundred and ninety four patients with pharyngotonsillitis diagnosis we isolated the same number of Streptococcus pyogenes, and possible beta-lactamase-producing-bacteria. RESULTS: In 180 patients (45.7%) we isolated at least one possible beta-lactamase-producing-bacteria. Of these, in 138 patients (35%) were confirmed the enzyme presence. In total, we isolated 218 possible beta-lactamase-producing bacteria, and 152 (69.7%) were beta-lactamase positive. We found no significant change in the in vitro susceptibility of group A Streptococcus to penicillin, but erythromycin resistance is relatively common, approximately 10% in this study. CONCLUSIONS: Streptococcus pyogenes was uniformly susceptible to all penicillins and cephalosporins in vitro. Erythromycin treatment should not be promoted as first-line therapy because the consequent increase of bacterial resistance could create difficulty in treating penicillin-allergic patients. Because of the poor activity of trimetoprimsulfametoxazol, this drug no longer can be considered the drug of choice for the management of group A Streptococcal infections.

Bacterial vaginosis a "broad overview".

Bacterial vaginosis (BV) was first reported in 1995 by Gardner and Dukes, who described the unique clinical signs and symptoms and the distinctive nature of the vaginal discharge associated with it. They also described a "new" causative organism, which they named "Haemophilus vaginalis", subsequently renamed Gardnerella vaginalis. BV is currently the most prevalent cause of infectious vaginitis among women attending for genitourinary diseases. BV has a complex microbiology. Lactobacillus populations, which are usually dominant in healthy women, are replaced by a polymicrobial group of organisms that includes G. vaginalis, anaerobic Gram-negative rods such as Prevotella species, Peptostreptococcus species, Mycoplasma hominis, Ureaplasma urealyticum, and often Mobiluncus species. Anaerobic bacteria produce enzymes, aminopeptidases, that degrade protein and decarboxylases that convert amino acids and other compounds to amines. Those amines contribute to the signs and symptoms associated with the syndrome, raising the vaginal pH and producing a discharge odor. The excessive amounts of bacteria characteristic of the syndrome attach to epithelial cell surfaces, resulting in "clue cell". Nearly half the patients report no noticeable symptoms, but many develop a characteristic copious, malodorous discharge if untreated. Results from epidemiologic studies have associated BV with serious upper genital tract infections and adverse pregnancy outcome. In particular, the presence of BV in pregnant women increases the risk of preterm delivery, and evidence is now compelling that BV is a cause of preterm delivery. The interest in potential invasiveness of G. vaginalis has increased. However, virulence determinants have not been studied enough. The most important therapy includes clindamycin and metronidazole.

Symptomatic bacteriuria due to Ureaplasma and Mycoplasma in adults.

314 women, and 52 men were screened during 18 months, for the presence of Ureaplasma urealyticum and Mycoplasma hominis in a midstream specimens of urine. All the patients were adults with symptoms of urinary tract infection who consulted a physician at a Primary Health Center "José Castro Villagrana" in Tlalpan, D.F. México. Ureaplasma urealyticum was isolated in 54 (17.1%) of the women and 8 (15.4%) of the men. Only Escherichia coli and Gardnerella vaginalis were isolated more frequently in both groups, 36.6% and 25.4%, respectively in women and 58.5% and 30.8% in men Mycoplasma hominis was isolated in 12 (3.8%) in women and 4 (7.7%) in men. The bacteriuria due to fastidious bacteria or Ureaplasmas that is not detected by routine culture methods are relatively common and would not necessarily respond to antibiotic treatment for conventional urinary tract pathogens.

Biotypes of Gardnerella vaginalis isolated from urinary tract.

A modified scheme is proposed for biotyping Gardnerella vaginalis isolated from urinary tract of symptomatic and asymptomatic women based on detection of hippurate hydrolysis, beta-galactosidase (ONPG) and lipase, and fermentation of arabinose, galactose and xylose. Thirty biotypes were found among 73 strains. The distribution of biotypes was similar in both populations but the biotypes 1H, 5G and 7G were found more frequently in women without symptoms of urinary tract infection.

[Gardnerella vaginalis biotypes: modification of a proposed system]. / Biotipos de Gardnerella vaginalis: modificación de un sistema propuesto.

A modified scheme is proposed for biotyping Gardnerella vaginalis based on detection of hippurate hydrolysis, beta-galactosidase (ONPG) and lipase, and fermentation of arabinose, galactose and xylose. Thirty three biotypes were found among 140 strains from women with and without bacterial vaginosis (non-specific vaginitis). The distribution of biotypes were found to be significantly different, being more predominant the biotypes 1A; 5G; 7A; 7D and 7G in women with vaginosis and the biotypes 5G and 6H in women without vaginosis. These data suggest that some biotypes of Gardnerella vaginalis are associated with bacterial vaginosis.