Antibiotic resistance among Gram-negative non-fermentative bacteria at a teaching hospital in Saudi Arabia.

The incidence and antimicrobial resistance of Gram-negative non-fermentative bacteria isolated over 1 year at King Abdulaziz University Hospital, Jeddah, Saudi Arabia were investigated. A total of 499 of these microorganisms were collected and account for 16% of all Gram-negative bacteria isolated. The most common species were Pseudomonas aeruginosa 291 (56%), Acinetobacter baumannii 170 (34%), and Stenotrophomonas maltophilia 35 (7%). 168 (34%) of these microorganisms were isolated from Intensive Care Unit (ICU), 147 (30%) from General Medicine, and 24 (25%) from Surgery wards. ICU was the main site of isolation of P. aeruginosa and S. maltophilia, while A. baumannii was more frequently isolated from medicine and surgery units. The vast majority of the isolates were resistant to many antibiotics tested. The antimicrobial resistance patterns of P. aeruginosa showed lowest resistance to imipenem (13%), amikacin (17%), and ciprofloxacin (18%). Imipenem was also the most active antimicrobial agent against A. baumannii (15%) resistance. S. maltophilia exhibited multi-drug resistance, and was susceptible only to sulfonamide (6%).

Postoperative wound infection at a university hospital in Jeddah, Saudi Arabia.

A prospective study was made of 1418 surgical wounds at the 250-bed King Abdulaziz University Hospital in Jeddah, Saudi Arabia. Daily examinations of wounds, cultures of all suspicious wounds and 28 days outpatient clinic follow-up were performed. The overall infection rate was 9%. The infection rate after clean surgery was 9.5%. High rates of infections were noted after colon resection (19%), caesarean section (19%), abdominal hysterectomy (10%) and cholecystectomy (10%). The infection rates after appendectomy, mastectomy and herniorrhaphy were approximately 7%. A lower rate of infection was seen after thyroidectomy (2%). The incidence of infection was significantly related to pre-operative stay in hospital and to duration of operation.

Comparative in-vitro activity of fourteen antibiotics against clinical isolates of enterococci.

The in-vitro antibacterial activities of fourteen antimicrobial agents, including ampicillin, amikacin, Augmentin, ceftazidime, cefotaxime, ceftriaxone, ciprofloxacin, erythromycin, gentamicin, penicillin G, piperacillin, rifampicin, streptomycin and vancomycin, were compared against 195 enterococcal strains isolated from clinical specimens received at the King Abdulaziz University Hospital in Saudi Arabia. The antibacterial susceptibility was determined by the minimal inhibitory concentration (MIC) using an agar dilution method. Ampicillin, Augmentin and vancomycin exhibited the greatest activity, inhibiting 90% of the tested strains (MIC90) at 2 micrograms/ml, followed by penicillin G and piperacillin with MIC90 of 4 micrograms/ml. Erythromycin, third generation cephalosporins, aminoglycosides and rifampicin, on the other hand, had poor activity against enterococci with MIC90s well above the obtainable serum concentrations. The clinical implications of resistance to aminoglycosides and the alternative antimicrobial therapy in serious enterococcal infections are discussed in the text.

Comparative in vitro activity of amoxycillin/clavulanate (augmentin), ceftazidime and ceftriaxone against hospital strains of gram-negative and -positive bacteria.

The in vitro antibacterial activities of amoxycillin/clavulanate (Augmentin), ceftazidime and ceftriaxone were compared against 330 gram-negative and gram-positive strains isolated from clinical specimens received at the King Abdulaziz University Hospital (KAUH) in Saudi Arabia. The antibacterial susceptibility was determinated by Stokes method and by the minimal inhibitory concentration (MIC) using an agar dilution method. Ceftazidime and ceftriaxone were the most active antibiotics, inhibiting 90% of the tested strains by obtainable serum concentrations. Augmentin, on the other hand, had much lower activity against most of the strains tested. Ceftazidime's activity was superior to that of ceftriaxone especially against Klebsiella spp., Enterobacter spp., Citrobacter diversus, indole positive Proteus, Providencia stuartii, Acinetobacter calcoaceticus and Pseudomonas aeruginosa. Ceftriaxone had better activity against Serratia orderefera, Morganella morganii and Staphylococcus aureus. Beta-lactamase stable cephalosporins are therefore a potential replacement for aminoglycosides in the antimicrobial therapy of serious Gram-negative infections and alternative agents in the treatment of some Gram-positive infections.

Effect of ofloxacin on the pharmacokinetics of a single intravenous theophylline dose.

The effect of ofloxacin taken for 8 days (200 mg twice daily) on the pharmacokinetics of a single intravenous dose of theophylline (4.3 mg/kg over 15 min) was studied in a crossover procedure among seven healthy male volunteers. Theophylline concentrations were measured serially for 10 h by the immunofluorescence polarization technique. No significant effect of ofloxacin was found on theophylline clearance, half-life, or volume of distribution. It is therefore concluded that ofloxacin and theophylline can be safely administered together.

Nomarski differential interference contrast studies of murine lymphocytes.

Nomarski differential interference contrast microscopy (DIC) of lymphocyte surface morphology was combined with immunofluorescence studies on T and B cell markers on the thymus, lymph nodes, spleen, peripheral blood lymphocytes and thoracic duct lymph of female CBA mice. DIC identified smooth cells and several categories of villous cells; more extreme forms were present in lymph. Most B cells seemed to belong to the smooth group and most peripheral T cells to the villous group. Thymus cells were almost entirely smooth, but treatment with cortisone increased the proportion of villous cells to 50%. The surface morphology of lymphocytes was highly labile preventing direct identification or separation of T and B cells. In vivo removal of T cells by adult thymectomy, lethal irradiation and bone marrow reconstitution caused the villous cells to decrease. During recovery from irradiation, T lymphocytes tended to parallel villous cells, B lymphocytes smooth cells, but were differences between the spleen and lymph nodes. Mice deprived of T1 cells by adult thymectomy showed a modest decrease of smooth cells in the spleen and blood; mice depleted of T2 cells by anti-lymphocyte serum, or which were naturally deficient in T2 cells, were markedly lacking in villous cells. Thoracic duct lymph, which is rich in T2 cells, had a high proportion of extremely villous lymphocytes. Exposure to lymph induced extreme villous features in lymph node cells, and it was found that the thoracic duct lymph was markedly hypertonic to serum, although varying in osmolarity throughout the day. It is suggested that the villous shape of T2 cells is a circulatory adaptation, necessitated by the peculiar character of the lymphatic system in mice.