PubMed Health⌕ Search

Biomedical subjects

A M Rafay

Publications and source records attributed to A M Rafay.

8 recordsLinked to original sources
PubMed2001

Low frequency of bacteraemia during eye surgery obviates the need for endocarditis prophylaxis.

PURPOSE: To determine the incidence of bacteraemia following eye surgery, and thereby evaluate the need for antibiotic cover during such procedures, in patients who are at risk for bacterial endocarditis. METHODS: This prospective study involved 50 consecutive patients undergoing extraocular surgery at the Sultan Qaboos University Hospital, Muscat, Oman. Local preparation of the surgical site in all patients included pre-operative instillation of 0.3% gentamicin and 3% povidone-iodine eye drops. Two eye swabs (one from the conjunctival sac and another from the eyelid margin) and two venous blood samples (one taken just before the procedure and the second 10 min into it) were collected and cultured for aerobic and anaerobic bacteria. Surgery-related bacteraemia was defined as a negative pre-operative blood culture followed by a positive intraoperative blood culture of the same bacterium identified in the positive eye swab. RESULTS: Only two patients (4%) demonstrated surgery-related bacteraemia: one caused by Staphylococcus epidermidis (following entropion correction) and the other by Haemophilus influenzae (following dacryocystorhinostomy). Four other patients had positive conjunctival swabs without bacteraemia, the causative organisms being Haemophilus influenzae in two, and Staphyloccus aureus and Klebsiella pneumoniae in one each. CONCLUSION: Ophthalmic surgery is not associated with significant bacteraemia, and therefore does not mandate routine antibiotic cover in patients at risk for bacterial endocarditis. Stringent pre-operative preparation of the surgical site may suffice to minimise bacteraemia; however, this requires further study.

Adolescent↗
PubMed2001

Comparative in-vitro activity of trovafloxacin and other related drugs against isolates of streptococcus oralis.

OBJECTIVE: The in-vitro activity of trovafloxacin a new quinolone was compared with that of ciprofloxacin, erythromycin, various b-lactam and other appropriate antibiotics such as vancomycin, teicoplanin and clindamycin against 60 isolates of S. oralis. METHODS: Minimal inhibitory concentration was performed using the agar dilution technique and micro-titer method. In addition minimal bactericidal concentration and time-kill studies were carried out to estimate the bactericidal activity of trovafloxacin against S. oralis isolates. RESULTS: Trovafloxacin showed a four-fold increase in activity over ciprofloxacin, with a narrow minimal inhibitory concentration range, MIC50 and mode values of 0.25 mg/l. Although the minimal inhibitory concentrations of trovafloxacin for S.oralis were relatively high compared to all the antibiotics tested. The in-vitro bactericidal activity of Trovafloxacin was greater than all other antibiotics against S. oralis. Five out of 10 isolates showed there was a 100% kill within 6 hours of contact; in all other cases, the kill time was between 6 and 24 hours. CONCLUSION: Overall, trovafloxacin showed superior minimal inhibitory concentration, bactericidal concentration and kill time when compared with different antibiotics.

Anti-Infective Agents↗
PubMed1998

Incidence of Dientamoeba fragilis in faecal samples submitted for routine microbiological analysis.

Over a six-month period, 857 faecal samples were submitted to the Department of Microbiology and Immunology at Sultan Qaboos University Hospital in Oman, for routine microbiological examination. All samples were stained using the Gomori trichrome method. Trophozoites of Dientamoeba fragilis were detected in 41 (5.1%) patients, making it the most common enteropathogen found in the study. Of the patients with pure D. fragilis infection, 83% had abdominal pain, the duration of which varied from one month to two years. The use of permanently stained smears allowed detection of D. fragilis for the first time in the Sultanate of Oman.

Adolescent↗
PubMed1997

The in-vitro activity of trovafloxacin, a new fluoroquinolone, against Gram-positive bacteria.

The in-vitro activity of trovafloxacin, a new quinolone, was compared with that of ciprofloxacin, erythromycin, various beta-lactam antibiotics and, where appropriate, clindamycin and vancomycin against a range of Gram-positive bacteria including staphylococci (n = 201), Streptococcus pneumoniae (n = 83), beta-haemolytic streptococci (n = 46), viridans group streptococci (n = 100), Streptococcus milleri (n = 18) and enterococci (n = 161) by an agar dilution technique. In addition, time-kill studies were performed to estimate the bactericidal activity of trovafloxacin against S. milleri and viridans group streptococci. Trovafloxacin was the most active agent tested against staphylococci. It also showed good activity, at least four-fold and usually eight- to 16-fold that of ciprofloxacin, against all the streptococci. Trovafloxacin showed good activity against vancomycin-sensitive Enterococcus faecalis and Enterococcus faecium, but was less active against the 11 isolates of vancomycin-resistant enterococci. Trovafloxacin showed comparable or superior bactericidal activity to amoxycillin against the S. milleri and viridans group streptococci tested.

Anti-Bacterial Agents↗
PubMed1996

Effect of mucin and glucose on proteolytic and glycosidic activities of Streptococcus oralis.

The production of glycosidase and protease activities, which may play a role in the degradation of human glycoproteins, by Streptococcus oralis strains isolated from endocarditis, septicaemia or the oral cavity was investigated with a range of fluorogenic substrates. The pH optima of the proteases ranged from 6.0 to 9.3 and the pH optima for the glycosidases were lower (4.5-6.0), although the pH range over which both groups of enzymes acted was broad. Growth in a minimal medium supplemented with glucose resulted in repression of glycosidase activities and elevated proteolytic activity. Bacteria from cultures supplemented with porcine gastric mucin (PGM), a model glycoprotein, exhibited higher levels of glycosidase activity, while proteolytic activity was suppressed and glycoprotein-derived monosaccharides were transported at significantly higher rates than those observed for cells grown in media with glucose. PGM-derived cells also exhibited high levels of N-acetylneuraminate pyruvate-lyase, the first intracellular enzyme in the pathway of sialic acid catabolism. Taken together, these data indicate that S. oralis strains produce a range of proteolytic and glycosidic enzymes that may play a role in the degradation of host-derived glycoproteins.

Amino Acid Sequence↗
PubMed1992

Chloramphenicol-resistant typhoid fever: an emerging problem in Oman.

Until recently multiply drug-resistant Salmonella typhi was uncommon in the Sultanate of Oman. In 1990 the first isolate of chloramphenicol-resistant S. typhi from an Indian expatriate was reported. In 1991, 58 cases of typhoid fever were diagnosed, of whom 19 (33%) were resistant to chloramphenicol. All patients with chloramphenicol-resistant S. typhi are either Indians or Omani with a history of recent travel to India. Chloramphenicol may not be the appropriate blind therapy for such patients. Ciprofloxacin may be the alternative.

Chloramphenicol Resistance↗