Haemophilus influenzae type b in a nursery school: the value of biotyping.

Meningitis due to Haemophilus influenzae serotype b biotype II occurred in a 2-year-old child who attended a nursery school along with 26 other 2-year-old children. Nasal swabs from these 26 contacts revealed a H influenzae type b colonization rate of 50% (13/26); simultaneously performed throat swabs detected a colonization rate of 4% (1/26). Biotyping of the H influenzae type b isolates revealed that only 46% (6/13) were the same biotype as the index case; the remaining seven isolates were biotype III. All children received treatment with 20 mg/kg/day of rifampin administered by the nursery school attendant as a single dose for four days before the results of the cultures were known. Eradication of H influenzae type b carriage was successful in three of the six biotype II carriers and five of the six biotype III carriers available for follow-up culture. It was concluded that: (1) the culture site utilized in determining H influenzae type b colonization rates may markedly influence the results obtained; (2) biotyping may be a valuable epidemiologic tool in investigating the contacts of patients with H influenzae type b disease, and (3) failures of rifampin to eradicate the carriage of H influenzae type b from the nasopharynx may occur. The prudent approach to the management of young contacts of patients with serious H influenzae type b disease is to recognize their high risk status and to maintain close surveillance of them. The role of chemoprophylaxis with rifampin remains to be established.

Ecology of 350 isolates of group F Streptococcus.

The ecology of 350 strains of group F streptococci isolated from clinical material over a six-year period is described. The respiratory tract, particularly the throat, yielded the largest number of isolates. Wound swabs, mainly appendectomy, ranked second as a source of this organism, followed closely by the genitourinary tract. A significant proportion of strains was recovered from gastrointestinal sites. Dental abscess yielded several strains, often in pure culture, and the external auditory canal was identified as minor locale of the group F streptococcus. A few isolates were also obtained from blood, cerebrospinal fluid, and miscellaneous tissues.

A comparison of conventional and Minitek systems for biotyping Haemophilus influenzae.

Two hundred pediatric isolates of Haemophilus influenzae from various sources were biotyped using the media described by Kilian in parallel with the Minitek system. There was an excellent correlation (97.7%) between the two systems. Ninety-five per cent of blood and cerebrospinal fluid (CSF) isolates were biotype I. Biotypes II and III were most frequent among isolates from sources other than blood and CSF. Production of beta-lactamase was limited to biotype II in the blood and CSF isolates, but was fairly evenly distributed among the biotypes from other sources. The Minitek system is an acceptable alternative to conventional media for biotyping H. influenzae.

Susceptibility of Gardnerella vaginalis to metronidazole, its bioactive metabolites, and tinidazole.

The susceptibilities of 510 clinical isolates of Gardnerella vaginalis to metronidazole, its principal oxidative metabolites, and tinidazole were determined by an agar dilution method. The hydroxy metabolite was the most active, with an MIC90 value (minimum concentration that inhibited 90% of the strains) of 1.12 mg/L (5.51 mumol/L). Tinidazole and metronidazole were somewhat less active, with MIC90s of 4.09 mg/L (23.9 mumol/L) and 4.44 mg/L (18.0 mumol/L), respectively. The acid metabolite was inactive, with an MIC90 value of 226.55 mg/L (1.22 mmol/L). These results suggest that the hydroxy metabolite of metronidazole may contribute significantly to the antimicrobial effect of the parent drug in G. vaginalis-associated infections.

Outbreak of Acinetobacter baumannii in an intensive care unit associated with tracheostomy.

A case-control study was conducted to determine risk factors for acquisition of an epidemic strain of Acinetobacter baumannii in an intensive care unit. The epidemic strain was identified by pulsed-field gel electrophoresis and was isolated from tracheal secretions in 13 (87%) of 15 patients. In a logistic regression analysis, presence of a tracheostomy was an independent risk for Acinetobacter sp acquisition (odds ratio, 421; 95% confidence interval, 13.8-12925; P =.001) and the strength of the association was inversely related to the duration of mechanical ventilation. The outbreak coincided with the introduction of a policy of early percutaneous tracheostomy in the intensive care unit and probably resulted from inadequate infection control practices during respiratory care. No environmental reservoir was found. Institution of contact precautions, enhanced handwashing, and staff education was associated with resolution of the outbreak.

Branhamella catarrhalis bacteraemia and immunosuppression--part of a larger problem?

Attention is drawn to the striking association between bacteraemia due to Branhamella catarrhalis and immunosuppression and evidence is cited suggesting a special relationship between this and other Neisseria of intermediate virulence and systemic disease in the immunologically compromised.

Clinico-diagnostic experience with tuberculous lymphadenitis in Saudi Arabia.

OBJECTIVES: To describe the diagnosis and outcomes of tuberculous lymphadenitis in a low HIV-seroprevalence population at a hospital in Riyadh, Saudi Arabia. METHODS: Retrospective case series of tuberculous lymphadenitis from 1983 to 1998 were examined. RESULTS: There were 99 cases with a median age of 38 years and a female preponderance (female/male ratio of 1.3 : 1). Eighty per cent had cervical involvement and 36% had systemic symptoms. Eighty-nine per cent had their lymphadenopathy for more than 1 month. The diagnostic yield of tuberculin skin testing was 83%, of chest X-ray was 27%, of fine-needle aspiration was 46%, and of excisional lymph node biopsy was 97%. Only one-third of patients received a tuberculin test. There was no significant difference in outcome between 6 and 9 months of chemotherapy, and paradoxical enlargement of nodes occurred in only 6%. CONCLUSIONS: Tuberculous lymphadenitis in our study population was predominantly cervical in location. The diagnostic yield of FNA was lower than that reported in the literature, and might be improved by more frequent tuberculin skin testing, multiple aspirations of lymph nodes, or use of excisional biopsy as the initial diagnostic procedure. Most patients responded well to chemotherapy, with few complications.

Successful treatment of Candida endophthalmitis with a synergistic combination of amphotericin B and rifampin.

Candida endophthalmitis, caused by transient candidemia, developed in a 14-year-old white girl receiving intravenous hyperalimentation. Antifungal synergism was established in vitro for the combination of amphotericin B and rifampin against the C. albicans isolate. A combined ten-day course of intravenous amphotericin B and oral rifampin was followed by the elimination of the infection and the preservation of good visual acuity.

Metronidazole, its bioactive metabolites and acne.

Metronidazole's activity has been established in both acneiform rosacea and acne vulgaris. Recent research indicating that the breakdown products of several antibiotics, including metronidazole, may have considerably greater activity than the parent compound, prompted a re-examination of the susceptibility of Propionibacterium acnes, the organism involved in the fundamental pathogenesis of acne vulgaris. Although the organism was marginally more sensitive to the hydroxy derivative, MIC levels were still outside the readily attainable therapeutic range. The beneficial effects of metronidazole in acne vulgaris are attributable to its anti-inflammatory activities rather than its antibacterial ones.

Integrated management of bacteraemic shock in neutropenia.

The neutropenic mouse model of endotoxin-associated, enterobacterial sepsis was used to evaluate the individual and cumulative effects of anti-infective, anti-endotoxic, anti-inflammatory and anti-endorphic strategies. Survival was maximized following the administration of ticarcillin, polymyxin, methylprednisolone and naloxone.

Anaerobic infection in the neutropenic host: anti-endotoxin effect of polymyxin.

The neutropenic mouse model of endotoxin-associated anaerobic sepsis was used to evaluate the anti-endotoxic effect of polymyxin. Administered as two spaced doses after lethal challenge with Bacteroides fragilis polymyxin produced a statistically significant protective effect.

Endophlebitis of the leg caused by brucella infection.

Brucellosis is hyperendemic in Saudi Arabia where, despite rapid urbanisation, a large segment of the population has a nomadic background and clings to cultural traditions such as the drinking of raw milk. We report here an unusual complication of brucellosis in a microbiology technologist. A 41-year-old male presented with an 8-day history of right ankle pain which, over a 3-day period, extended up to his calf where swelling and tightness developed. The leg symptomatology occurred on a background of fever, seats and rigors. X-ray of the limb was normal but a venogram revealed thrombosis of the deep veins of the right calf. Although his blood culture was negative, he developed high brucella antibody titres. Treatment with anticoagulants combined with a course of doxycycline and rifampin produced a full recovery.

The use of direct susceptibility tests from BACTEC 9240 to Microscan Walkaway.

Using a straight-from-the-bottle into-the-instrument technique, a series of direct susceptibility tests were performed with the BACTEC 9240 and Microscan Walkaway systems. Although rapid, unacceptably high error rates were obtained when compared with a standardized method. This procedure is not sufficiently accurate for clinical use.

First case of combined blastomycosis and tuberculosis in a patient from Saudi Arabia.

Acute blastomycosis has not been reported on the Arabian Peninsula. We report an unusual case of dual pulmonary blastomycosis and tuberculosis. In addition, this is the first case of blastomycosis reported from Saudi Arabia, a disease not endemic in this region.

The cost-saving potential of prevaccination antibody tests when implementing a mass immunization program.

A seroprevalence study of hepatitis A virus (HAV), hepatitis B virus (HBV), and varicella-zoster virus (VZV) was carried out among Saudi Arabian National Guard soldiers with the objective of determining the cost-saving potential of prevaccination antibody tests when implementing an immunization program for the soldiers. A systematic sampling of 450 blood samples from 1,350 soldiers who donated blood at our hospital was carried out. Antibody tests were performed using the enzyme-linked immunosorbent assay method. The seropositivity rates for antibodies to HAV, HBV, and VZV were 97.5, 17.8, and 88.5%, respectively. Comparing the cost of prevaccine screening with that of universal vaccination, it was estimated that savings of 76 and 32% could be effected for HAV and VZV. Conversely, screening for HBV before immunization could increase the cost of vaccinating against the disease by 49%. A seroprevalence study could be a useful cost-saving approach to a mass immunization program against endemic, natural immunity-conferring diseases.

Fortuitous detection of campylobacter bacteremia.

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