Abstract: A total of 107 antibiotic-resistant propionibacteria were isolated from the face of 102 Egyptian acne patients, dermatology staff and controls. Erythromycin-clindamycin-resistant propionibacteria were chosen to detect erm(X) gene and it was detected in 29 of 107 (27%) strains. However, just 7 strains had IS1249I, 3 of them had also Tn5432. The erm(X) gene which is not carried on Tn5432 confers inducible resistance to telithromycin by erythromycin or clindamycin. The DNA sequences of the PCR amplification products of this new erm(X)-mediated antibiotic resistance showed >99% identity to the erm(X) gene isolated from a Corynebacterium jeikeium. Southern blotting analysis of the erm(X)-specific probe shows that there were two copies of this resistance gene integrated within the chromosomal DNA. This is the first report of erm(X) being carried by Propionibacterium acnes outside Europe. Whilst the gene is associated with Tn5432 in some strains, the data suggests other genetic element carrying erm(X). The high carriage of erm(X) may affect the efficacy of clindamycin and macrolides for acne treatment in Egypt.
Abstract: Purpose: The purpose of the current study was to evaluate two low-costing PCR assays for rapid detection of Group B Streptococcus (GBS) in comparison to a pigment-based culture method. Materials and Methods: One-hundred and fifty vaginal swabs were collected from pregnant women at 35-40 weeks of gestation. Vaginal swabs were inoculated in selective enrichment broth medium, and examined using Islam medium, cfb PCR and scpB PCR assays. The demographic data were analysed to identify independent predictors of GBS colonization (age and gravidity), with GBS status as the dependent variable. Results: There was a significant association of age and gravidity with GBS colonization. GBS was detected in 25.3% of isolates by Islam medium, in 30.6% by using the cfb PCR assay and in 30% by using the scpB PCR assay. Conclusion: older pregnant women (≥30 years) and multigravida (>3 pregnancies) are at higher risk of GBS colonization. Both scpB-gene and cfb-gene-based PCR methods are highly sensitive techniques (100% sensitivity) compared to culture method. However, the specificities of the scpB and cfb PCR assays were 93.75 and 92.85%, respectively.
Abstract: Group B Streptococcus (GBS) infection has long been recognized as a frequent cause of morbidity and mortality in newborn infants. The purpose of this study was to determine the colonization rate with GBS and the antibiotic susceptibility profile in pregnant women attending Gynecological clinics in Egypt. One-hundred and fifty vaginal swabs were collected from pregnant women at 35-40 weeks of gestation. In comparison to culture, direct latex agglutination testing revealed 100% sensitivity and 93.75% specificity. Thirty-eight specimens (25.3%) were found to be positive for GBS. Each isolate was tested for susceptibility to penicillin G, ampicillin, cefotaxime, erythromycin, clindamycin and vancomycin. Erythromycin-resistant isolates were further classified by double-disk method. All isolates were susceptible to penicillin G, ampicillin and vancomycin. Resistance to cefotaxime was detected in three isolates (7.89%). Five isolates (13.15%) were resistant to erythromycin and nine isolates (23.68%) were resistant to clindamycin. Four (80%) isolates had constitutive macrolide-lincosamide-Streptogramin(B) resistance (cMLSB(B)) resistance and one (20%) isolate had inducible resistance (iMLS(B)) resistance. GBS colonization was found to be high in our region. Latex agglutination testing and Islam medium are reliable methods to detect GBS in late pregnancy; however, latex agglutination test is rapid and simpler. Penicillin G remains the first choice antibiotic for treatment of GBS infections.
Abstract: The utility of Rambach agar to identify Salmonella spp. was examined relative to its usefulness in clinical microbiology. Forty-four of 54 (82%) salmonella organisms isolated from faecal cultures and 66 of 82 (84%) salmonella stock cultures produced bright red colour colonies after 24 h incubation at 37 degrees C, whereas 48 of 54 (89%) salmonellae isolated from faecal cultures, and 74 of 82 (90%) salmonella stock cultures, yielded the bright red colour when the incubation time was extended to 48 h. Apart from Salmonella typhi and Salmonella paratyphi A the sensitivity of Rambach agar to detect salmonella strains belonging to five serogroups was 83% and 92% after 24 and 48 h of incubation, respectively. In contrast, other members of the family Enterobacteriaceae tested failed to give the bright red colour, except for one strain of Pseudomonas aeruginosa and another of Acinetobacter baumannii. The non-salmonella strains either gave a different colour--blue, green or orange--or were colourless. To supplement the use of Rambach agar in the detection of Salm. typhi and Salm. paratyphi A and other late or negative acid-producing salmonella species on this medium, the 4-methylumbelliferyl caprylate fluorescence (MUCAP) test was carried out, and this showed positive results with all the salmonella strains tested. These results suggest that while Rambach agar can not pre-identify Salm. typhi and Salm. paratyphi A, the use of a simple and rapid (MUCAP) test in combination would make it very useful to identify all Salmonella spp. after 24 h incubation.
Abstract: During a period of 28 months, 114 isolates of Acinetobacter baumannii obtained from urine samples of 57 patients, were recovered in a Spinal Cord Unit; an unusual increase in the number of A. baumannii isolates was observed between February 1991 and January 1992. Six different typing methods [biotyping, antimicrobial susceptibility, whole cell and cell-envelope protein analysis, plasmid analysis and chromosomal DNA analysis by pulsed-field gel electrophoresis (PFGE)] were used to study the isolates to establish any potential relationships among them. Chromosomal DNA analysis by digestion with ApaI and separation of the fragments by PFGE was the most powerful tool to determine the relatedness of isolates. The results suggest that the isolates from 1991 and 1992 may have originated from strains present in 1990 that subsequently acquired resistance to amikacin and tobramycin during the epidemic.
Abstract: Shigella isolates were identified as a cause of traveler's diarrhea in 67 (10%) of 675 patients and were tested for resistance to seven antimicrobial agents in a comparative study with those causing nontraveler's diarrhea in Spain. Ampicillin and chloramphenicol resistance was more frequent in Shigella flexneri (60 and 46%, respectively) than in Shigella sonnei (32 and 18%, respectively) and in travel-related isolates (P < 0.05 and 0.04, respectively). Of S. sonnei isolates from patients with traveler's diarrhea, 73 and 54% showed tetracycline and trimethoprim-sulfamethoxazole resistance, respectively, compared with only 8% of isolates from patients without a history of travel to developing countries (P < 0.007 and P < 0.0002). Low-level resistance to cephalosporins was found, whereas quinolone-resistant strains were not detected among travel-related Shigella isolates. Thus, quinolones may be an effective alternative therapy for travel-related shigellosis.
Abstract: Antimicrobial susceptibility testing was performed on 54 epidemiologically unrelated clinical isolates of Acinetobacter baumannii by using a standard agar dilution technique. On the basis of the in vitro activities, imipenem and doxycycline were the most active agents, whereas amikacin, isepamicin, and the new fluorquinolones ciprofloxacin and ofloxacin presented moderate activity. Cephalosporinase activity was found in 98% of the strains, whereas lactamases of TEM type 1 and one with a pI of 7 to 7.5 were present in 16 and 11% of the strains, respectively. Resistance to aminoglycosides was explained by the production of the three classes of aminoglycoside-modifying enzymes, with predominance of aminoglycoside-3'-phosphotransferase VI in 28% of the strains.
Abstract: Vibrio cholerae is oxidase positive, a primary characteristic used to differentiate it from Enterobacteriaceae. But false negative oxidase test results have been obtained with colonies from thiosulphate-citrate-bile salts-sucrose (TCBS) agar medium. A rapid oxidase test procedure is described here. This takes 1 min, avoids false negative results and the necessity to grow the bacteria in a general-purpose medium. The bacteria may be recovered after the test and used for further investigations.
Abstract: The present study investigates the contribution of gastric mast cells on PGD2 generation in rat gastric mucosa. Cold-restraint induced stress or i.v. carbachol injection methods were used for gastric mast cell degranulation. In 19 stressed, 15 carbachol-infused and 14 control rats, gastric mast cell counts and gastric mucosa PGD2 assay were performed. Gastric mucosal content of PGF2 alpha was also determined in carbachol infused and control rats. The mean number of gastric mast cells was significantly lower in stressed and carbachol infused than in control rats. Despite these differences in gastric mast cell counts, neither PGD2 or PGF2 alpha contents in the gastric mucosa were significantly different in mast cells degranulated rats than in control animals. These results suggest another source of PGD2 in the rat gastric mucosa other than mast cells.
Abstract: A simple and rapid urease test to detect Campylobacter pylori infection was evaluated with bacterial culture as the "gold standard." The test was compared with the Gram stain and the conventional Christensen urease test. The culture method detected C. pylori in 29 of 49 gastric biopsy specimens. The rapid urease test showed 27 positive samples within 1 h at 55 degrees C (specificity, 100%; sensitivity, 93%) and 18 at room temperature (specificity, 100%; sensitivity, 62%). The Gram stain exhibited a sensitivity of 86% and a specificity of 91%. The conventional Christensen urease test detected C. pylori in only 4, 10, and 18 samples after 24, 48, and 72 h, respectively (sensitivities, 12, 36, and 60%, respectively; specificities, 95, 95, and 83%, respectively). We conclude that the rapid urease test is simple and highly specific for the detection of C. pylori and that it can be performed with small amounts of sample.
