Outbreak of group A streptococcal infection in a day-care center.

During an outbreak of streptococcal infections in a day-care center it is often difficult to determine the source and extent of the outbreak and the optimal means of management. An intervention strategy based on repeated throat cultures and initial antibiotic treatment of culture-positive individuals was used during an outbreak of respiratory tract infections with Group A streptococci at a day-care center. The spread of streptococci carriers was studied. Two weeks after the diagnosis of the index case, 61% of the 30 children were colonized with Group A streptococci. From 20 to 30% of the children remained streptococcal carriers, but they did not give rise to secondary cases. Initially the environment was heavily contaminated with Group A streptococci. Damp material might constitute a potential source of streptococcal spread. All Group A streptococcal strains belonged to the same serotype, T12M12. Prompt recognition and intervention are important to prevent spread of streptococcal infection to many day-care attenders.

Formula diet is a preventive factor in experimentally induced ideal ulcers in rats. A bacteriological study.

We earlier described an experimental model to create recurring chronic ileal inflammation with ulceration in the rat. A 2 cm segment of the distal ileum is excised but left attached to its intact mesentery; the ileum is reanastomosed. The ileal segment will seal off its open ends and a cyst-like structure of varying size will be formed, containing mucus, cell debris and bacteria. Approximately two thirds of the animals develop chronic inflammation with ulceration proximal to the ileal anastomosis. The ileal cyst and the surgical procedure on the distal ileum were shown to be prerequisites of the rat model for the development of lesions. We recently described that, in contrast to rats fed a standard diet, rats fed a hydrolyzed formula diet never developed inflammation or ulceration when subjected to the experimental procedure. In the present study we confirmed these observations and showed that the normal ileal flora (NIF) and the ileal cyst flora (ICF) were significantly influenced by the diets. The bacterial counts of both the aerobic and anaerobic NIF were 2 10log lower, i.e. > or = 99%, in rat fed the formula diet as compared to in those fed standard rat pellets. The NIF of the former group was represented by more aerobic species than the NIF of rats on the standard diet. Compared to the NIF there was a parallel increase in the bacterial counts of the ICF by approximately 2 10log CFU values in both groups of rats. The mean number of anaerobic species, mainly Gram-negative rods of the ICF, increased by approximately 70% in the rats on the standard diet that developed ileal ulceration, whereas identified aerobic species of the ICF decreased by 61% in rats on the formula diet and by 46% in those on the standard diet that did not develop ileal ulceration. The number of anaerobes in those groups of rats remained unchanged. The significant bacteriological differences between the rats that developed ileal ulcers and those which did not indicate that bacteria may be involved, directly or indirectly, in the development of chronic ileal ulceration.

Culture diagnosis of meningococcal carriers: yield from different sites and influence of storage in transport medium.

Different specimens and techniques have been used in the diagnosis of carriers of Neisseria meningitidis, reflecting the uncertainty about the optimal diagnostic procedure. In the present investigation the culture yield of meningococci from throat specimens was compared to that from nasopharyngeal speimens in 178 persons: 44 carriers were diagnosed. All of them were detected by culture of throat specimens while 34% of them would have remained undiagnosed if only nasopharyngeal specimens had been examined. Storage of throat specimens in a transport medium for 24 hours before culture gave a negative culture for meningococci in 41% of the carriers. This loss was surprisingly high, the reasons for which are discussed.

Relation between concentrations of metronidazole and Bacteroides spp in faeces of patients with Crohn's disease and healthy individuals.

Nine patients wih Crohn's disease and six healthy individuals were given 400 mg metronidazole twice daily and the concentration was measured in plasma and faeces 6 to 8 h after intake. Quantitative and qualitative bacteriological examinations were performed before and during treatment. The concentrations of metronidazole in plasma varied between 5 and 30 mg/l as measured by liquid chromatography (LC) and between 3 and 20 mg/l as measured by a bioassay (BA) method. There was no significant differences between the results of the two methods in patients but compared with BA the LC values were regularly lower in the healthy subjects. Metronidazole was detected in the faeces of most patients. These findings coincided with a significant reduction of Bacteroides spp in their faeces which was not apparent in healthy individuals in whom metronidazole was not detected in the faeces. Higher faecal metronidazole concentrations were found in patients with active disease and a total colon involvement as compared with the patients with a more quiescent disease and involvement of ileum and ascending colon only.

Antibiotic prophylaxis in operations on trochanteric femoral fractures.

Short-term prophylaxis against infection using cephalothin and cephalexin was studied in 140 patients operated on for trochanteric fractures of the femur. The group given the drug during preparation for anesthesia, intraoperatively, and for two days postoperatively had an infection rate of 1.8 per cent (one patient), whereas the group without prophylaxis had a rate of 16.9 per cent (twelve patients). The two groups were similar with regard to factors that may have influenced the infection rate, for example, age, time required for surgery, and blood loss. Staphylococcus aureus was the most common infecting organism, but several patients had mixed infections with intestinal bacteria.

Laboratory identification of pathogenic Neisseria with special regard to atypical strains: an evaluation of sugar degradation, immunofluorescence and co-agglutination tests.

Sugar degradation tests (SDT) were compared with immunofluorescence (IFL) and co-agglutination (COA) tests for the diagnosis of Neisseria gonorrhoeae (GC) and Neisseria meningitidis (MC). Somewhat more than 5% of the GC strains and 8% of the MC strains were misinterpreted by SDT. On most occasions the disagreement between SDT and serological tests was due to the inability of the MC strains (less so for GC strains) to degrade sugars correctly. Because of this, three out of 15 strains (20%) from pharyngeal specimens were primarily considered to be GC by SDT but were identified as MC by COA tests. Deficiencies in sugar degradations were also found in a group of clinical problem strains. Many of them were unable or had a decreased ability to degrade glucose or maltose but were diagnosed distinctly as MC by the COA test. There were no false positives with the IFL or COA tests, but 2% of the GC strains and 26% of the MC carrier strains (non-groupable) were not identified by COA. Both IFL and COA tests are good adjuncts to SDT for the diagnosis of GC and clinically significant MC, since the results are reliable and the tests rapid and simple to perform.

Use of a rapid fermentation test for indentification of anaerobic bacteria.

Rapid fermentation tests of carbohydrates were performed on 84 strains of anaerobic bacteria, and the result is compared with a commercially available micromultitest, API. An overall correlation of 87% was achieved between the two systems. The rapid fermentation test is easy to perform, since it is done aerobically, and easy to read. This study shows that RFT is useful in routine diagnosis of anaerobic bacteria, if it is used in combination with other relevant biochemical tests, morphologic examination, and gas chromatography.

Bacteriological and clinical studies of sulbenicillin.

A new semi-synthetic penicillin, sulbenicillin, was evaluated with regard to clinical effect on infections caused by Pseudomonas aeruginosa and other bacteria, serum concentrations obtained after intravenous administration and antibacterial spectrum, in comparison with the closely related antibiotic carbenicillin. The antibacterial spectra of sulbenicillin and carbenicillin were similar but the MIC values were lower for sulbenicillin against most of the bacterial strains tested. The serum concentrations obtained after administration of 5 g sulbenicillin were significantly higher than those obtained after 5 g carbenicillin although no significant differences in serum half-lives were observed. The clinical effect of sulbenicillin--alone or alternating with carbenicillin--on pseudomonas infections with varying localisation was found to be good in 11 and fair in 3 of 16 treated patients. Two treatment failures were cases of chronic wound infection. In addition to the pseudomonas infections, 9 of the patients also had concurrent infections with other bacteria, e.g. pencillinase-producing staphylococci and Klebsiella, and in all these cases bacterial growth was eliminated during therapy. No serious side effects were observed during sulbenicillin treatment but some of the patients developed massive growth of fungi in the urine, which disappeared after the treatment was stopped.

Meningitis and bacteremia due to Neisseria meningitidis: clinical and laboratory findings in 69 cases from Orebro county, 1965 to 1977.

The records for 69 patients with meningococcal disease during 13 years in Orebro County were reviewed. The mean incidence during this period was 2.0/100 000 persons/year. The age group less than 1 year had the highest incidence, 15/100 000 infants/year. The mortality was 7.2% and sequelae were found in 13% of the patients. Four factors were significantly more frequent in the 7 patients with psycho-neurological sequelae: (1) Age greater than 40 years; (2) A condition prior to meningococcal disease that might have been associated with a lowered resistance; (3) Muscular hypertonia and/or marked irritability on admission; (4) Fever greater than 8 days after initiation of adequate treatment. Prodromal symptoms from the upper respiratory tract were noted in 50% of the cases. Signs and symptoms before and on admission, laboratory data and complicating events were analysed for each of 4 groups: meningitis without meningococcemia (12 patients); meningitis with meningococcemia (46): fulminant meningococcemia without meningitis (6); and benign meningococcemia (5).

The effect of metronidazole and sulfasalazine on the fecal flora in patients with Crohn's disease.

Twenty patients with Crohn's disease were treated with metronidazole (Flagyl) or sulfasalazine (Salazopyrin). Before and during treatment quantitative and qualitative studies of the aerobic and anaerobic fecal bacterial flora were performed. After 1 week of metronidazole and 1 month of sulfasalazine treatment the median value of the Bacteroides concentration decreased drastically. After 4 months the Bacteroides concentration was still low in patients receiving metronidazole but normalized in patients receiving sulfasalazine treatment. The number of patients in whom the concentration of different bacteria in stool specimens showed changes during treatment of more than one 10log of colony-forming units (cfu) per gram wet weight (i.e. more than 90%) was calculated. A comparison between pretreatment samples and those taken at the end of treatment showed a statistically significant decrease of Bacteroides species (P less than 0.02) and a significant increase of fecal streptococci (P less than 0.02) in patients treated with metronidazole but not in patients treated with sulfasalazine. The relevance of these findings and the role of the bowel microflora for the pathogenesis of Crohn's disease is discussed.

Susceptibility of bacteroides species to metronidazole during treatment of patients with Crohn's disease and healthy individuals.

Patients with Crohn's disease are usually treated with metronidazole for long periods with the risk of selecting resistant bowel bacteria. This could have serious clinical and epidemiological implications, especially with regard to Bacteroides fragilis which is the most common cause of severe anaerobic infections. An investigation was therefore undertaken with the use of an agar dilution method to examine the susceptibility to metronidazole of B. fragilis and other common Bacteroides species isolated from faeces before, during and after treatment of patients with Crohn's disease amd healthy individuals. Before treatment, or during medication with sulphasalazine, 88% of the strain tested showed minimum inhibitory concentrations (MIC values) of less than or equal to 1 mg/l and none had MIC values greater than 4 mg/l. The MIC values were significantly increased during metronidazole treatment (p less than 0.02), with a maximum value of 8 mg/l. No significant changes were noted for the MIC values of strains isolated before and 1 week to 1 month after treatment (p greater than 0.1). It is concluded that it is important to examine the MIC values of bacteroides isolates from patients with long term treatment with metronidazole, especially with regard to treatment failure.

Recurrence rate of streptococcal pharyngitis related to hygienic measures.

OBJECTIVE: To test the hypothesis that treatment failures of streptococcal pharyngotonsillitis may be caused by reinfection by the patients' own streptococci remaining on a toothbrush or in the bedclothes. DESIGN: To elucidate the role of streptococcal contamination of the environment, hygienic measures regarding change of toothbrush and bed linen and washing of toys were given to half of the patients/families. Throat specimens were taken from all the patients before treatment with phenoxymethylpenicillin for 5 days, and the patients were followed-up for 1 month. At a home visit after 6-10 days, throat specimens were taken from the patients and all permanent residents of the home. Environmental samples were taken from pillowcases, floors, toothbrushes, dummies, and toys. SETTING: Six health care centres. SUBJECTS: 114 patients of all ages suffering from group A streptococcal pharyngotonsillitis, and 289 family members. MEASUREMENTS AND MAIN RESULTS: 54 patients/families received hygiene instructions. The total number of recurrences was 40 (35%). There was no difference in treatment failure rate between patients/families that had taken or not taken hygienic measures. CONCLUSIONS: Hygienic measures have no decisive influence on the risk of recurrence of streptococcal pharyngotonsillitis.

The use of protein A-containing staphylococci sensitized with anti-meningococcal antibodies for grouping Neisseria meningitidis and demonstration of meningococcal antigen in cerebrospinal fluid.

The co-agglutination technique, utilizing antibody coated protein A-containing staphylococci, was successfully adapted to grouping N. meningitidis strains. It was found to give more clear-cut results than the standard slide test, especially in the case of strains isolated from throat specimens. The co-agglutination technique has also other advantages over the standard slide test in the grouping of meningococci: minor influence by auto-agglutination, higher specificity, easy performance and low consumption of specific antisera. Preliminary results also showed that the co-agglutination technique could be applied for the rapid detection of meningococcal antigen in cerebrospinal fluid.