Haemophili from eyes.

The identity of haemophili isolated in our laboratories from eye swabs was investigated. Ten out of 114 strains belonged to capsulated types of H. influenzae. Seventy-six strains were submitted to tests for the identification of H. aegyptius (the Koch-Weeks bacillus), but none was proved to belong to this species. An unexpectedly high proportion of the haemophilus strains, including most of those with capsules, came from patients with lachrymal duct obstruction.

Wise Anaerobic Work Station: an evaluation.

The Wise Anaerobic Work Station permitted the growth of type cultures of a range of fastidious obligate anaerobes. In the isolation of anaerobic bacteria from clinical specimens the performance equalled that of a standard anaerobic jar incubated for 48 hours, and gave results superior to those obtained when incubation of jar cultures was interrupted at 24 hours. The Wise Anaerobic Work Station was easy to use and provided comfortable working conditions; running largely on industrial nitrogen, it was more economic than anaerobic cabinets or jars using conventional gas mixtures.

The API ZYM system in the identification of Gram-negative anaerobes.

The API ZYM reactions of type species of Gram-negative anaerobes representative of those encountered in human infections and of 56 clinical isolates of such organisms, identified by conventional techniques, were investigated. The API ZYM test clearly distinguished between the different genera and species examined and appears to provide a simple, reliable method for the identification of this group of organisms.

The effect of carbon dioxide on the sensitivity of Bacteroides fragilis to certain antibiotics in vitro.

The effect of 10% carbon dioxide on the sensitivity to four antibiotics of 10 strains of Bacteroides fragilis was studied. The minimum inhibitory concentrations of erythromycin and lincomycin hydrochloride for these strains were four to 32 times higher, when grown in hydrogen plus 10% carbon dioxide, than the values obtained when the strains were grown in pure hydrogen. A similar effect was obtained by growing the strains in hydrogen on an acid medium. Except for Haemophilus influenzae and Clostridium tertium the sensitivity to erythromycin and lincomycin hydrochloride of other species of bacteria examined was not affected by the atmosphere in which the tests were carried out. 7-Chlorolincomycin and rifamycin B diethylamide, to which the strains of B. fragilis were uniformly sensitive, were not significantly affected by additional carbon dioxide. The possible mechanisms underlying this phenomenon and its clinical implications are discussed, and a case report describing the successful use of erythromycin in the treatment of a cerebral abscess due to B. fragilis is presented. In a recent study in this laboratory of the sensitivity to antibiotics of B. fragilis the majority of strains were found to be inhibited by 0.15 mug/ml of erythromycin and by 0.55 mug/ml of lincomycin hydrochloride (Ingham, Selkon, Codd, and Hale, 1968). After this work had been completed hydrogen plus 10% carbon dioxide was substituted for pure hydrogen in the anaerobic technique. Strains of B. fragilis isolated on routine culture now appeared to be relatively resistant to erythromycin and lincomycin hydrochloride when their sensitivity was examined by the disc diffusion method. A more detailed investigation of this phenomenon was carried out, the results of which are reported here. The opportunity was also taken to examine the susceptibility of B. fragilis to two new antibiotics, namely, 7-chlorolincomycin and rifamycin B diethylamide.

A study in vitro of the sensitivity to antibiotics of Bacteroides fragilis.

During a two-year period of observation Bacteroides species were isolated from specimens of pus and vaginal swabs from 115 patients in this hospital. Thirty-five representative strains proved on examination to be Bacteroides fragilis. Minimal inhibitory and minimal bactericidal concentrations of six antibiotics for these strains were determined. All strains were resistant to streptomycin, neomycin, and polymyxin, slightly sensitive to penicillin and ampicillin, and fully sensitive to tetracycline, chloramphenicol, erythromycin, and lincomycin. The minimum bactericidal concentrations of chloramphenicol, erythromycin, and lincomycin were two to four times the minimal inhibitory concentrations. Tetracycline failed to exert any consistent bactericidal effect.The treatment of patients with infections caused by B. fragilis is discussed in the light of the findings in vitro.

A study of carbon dioxide-dependent strains of Streptococcus milleri.

Forty-four strains of non-haemolytic streptococci, from a variety of sites, that required CO2 for aerobic growth were identified as Streptococcus milleri. Of these strains, 40 (90%) possessed the Lancefield group-F antigen, the remainder being non-groupable with antisera to the group antigens A, C, F and G.

Characteristics of motile curved rods in vaginal secretions.

Motile curved rods seen in vaginal secretions have been isolated on Columbia agar supplemented with 5% human blood and vitamin K. Growth occurred anaerobically and in 5% oxygen but not in more aerobic conditions. There were two distinct groups of these organisms, distinguishable by morphology, biochemical activity and susceptibility to metronidazole. All isolates were sensitive to a wide range of antimicrobial agents, with the exception of nalidixic acid and polymyxin, but one group was resistant to metronidazole. There was little difference between the results of tests of susceptibility to aminoglycosides or to metronidazole performed in anaerobic and microaerophilic conditions. Motile curved rods were isolated from 18 of 80 patients with a clinical diagnosis of non-specific vaginitis, but from only two of 39 without the disease.

Phagocytosis and killing of bacteria in aerobic and anaerobic conditions.

Phagocytosis and intracellular killing of several facultative anaerobes were observed in aerobic and anaerobic conditions. The presence of anaerobes affected these processes. Bacteroides asaccharolyticus and B. fragilis were killed by phagocytes only at bacterial concentrations less than 1 x 10(7) cfu/ml; at higher concentrations of the anaerobes, killing of B. fragilis and concomitant facultative anaerobes was inhibited. This effect appeared to be due to an interaction, in appropriate reducing conditions, between anaerobe and serum, which allowed engulfment of organisms by phagocytes but markedly impaired intracellular killing.

Carbon dioxide laser irradiation of bacterial targets in vitro.

Agar targets seeded with Escherichia coli and Staphylococcus aureus in roll tubes simulating the vaginal vault were irradiated with a CO2 laser at various power densities and durations. Viable bacteria were detected in the plume emissions in all instances. Staphylococcus aureus was found to be more resistant to the thermal effects of lasing than E. coli. This suggests that CO2 irradiation of cervical lesions could disseminate viable particles which may be a hazard for patients and operators.

Simple peroperative antimicrobial chemoprophylaxis in elective neurosurgical operations.

From August 1981 to February 1982 postoperative infections due to different strains of penicillin-resistant Staphylococcus aureus occurred in 20 of 467 patients (4.3%) undergoing elective cranial and spinal operations. These infections were not attributable to defects in procedures or the theatre environment, therefore chemoprophylaxis was instituted. In the following 8 months, when patients were given penicillin G and sulphadiazine for 5 days commencing immediately postoperatively, S. aureus infections occurred in five of 579 patients (0.9%). In a subsequent randomized uncontrolled study, infections occurred in six of 265 patients receiving penicillin (2.3%), three of 270 receiving penicillin and sulphadiazine (1.1%) and one of 45 receiving erythromycin (2.2%) immediately postoperatively for 5 days. In a further study in which 587 patients received penicillin for 5 days commencing immediately preoperatively, infections due to S. aureus occurred in six (1.1%). Infections due to gram-negative organisms were seen in five (0.4%) of 1167 patients in the two uncontrolled studies.

Five days versus one day of penicillin as prophylaxis in elective neurosurgical operations.

Of 423 patients undergoing elective cranial and spinal operations, infections due to Staphylococcus aureus occurred in 3 of 217 (1.4%) receiving penicillin for 1 day, in none of 206 receiving penicillin for 5 days. There was no significant difference in rates of infection between the two groups receiving penicillin. It is concluded that penicillin for 1 day is as effective as penicillin for 5 days, in the prevention of wound infections due to S. aureus.

Fifteen-year review of the mortality of brain abscess.

Ninety consecutive cases of brain abscess admitted to this center between 1964 and 1978 have been reviewed. The overall mortality has fallen in three consecutive 5-year periods from 42 to 21 to 9.7%. A number of factors seem to be responsible for this. Early surgical intervention was associated with the reduction in mortality between the first and second 5-year periods. Recognition of the significance and extent of cerebral edema, confirmed since computed tomographic (CT) scans have been available, led to a greater use of steroids during the last 5-year period, but the number of patients thus treated was too small to permit an assessment of any effect on mortality. There is no evidence to suggest a change in the natural history of the disease, and surgical management has not altered significantly. Experience with CT scanning in this center in the diagnosis of brain abscess is limited. It is therefore not possible no assess whether any improvement in mortality may have arisen from the early and accurate diagnosis obtainable with this technique. Improvement in culture technique has been of major importance, leading to a better understanding of the bacteriology of brain abscesses. This has allowed a more rational antibiotic program to be instituted, in particular the use of agents active against obligate anaerobes.

A hospital outbreak of antibiotic-resistant Streptococcus pneumoniae.

We report six patients colonised with a multiply resistant strain of Streptococcus pneumoniae.

Focal infections of the central nervous system due to Propionibacterium acnes.

Propionibacterium acnes as the single cause of intracranial infections has rarely been described. We present four patients in whom the infection arose as a result of a breach of skin tegument, and postulate that P. acnes is an under-recognised pathogen.

Abnormal phagocytic function in children under one year of age.

The action of white blood cells (WBC) against Proteus mirabilis was assayed in 22 children following meningitis or septicaemia and compared with that in control groups of: (1) adult volunteers, (2) children undergoing minor surgical procedures for non-infective conditions, and (3) children being investigated for suspected renal disease. WBC bacterial killing tests were normal in all 55 adult volunteers. Abnormal results were obtained in 11 of 22 (50%) children with meningitis or septicaemia, 10 of 21 (47.6%) children undergoing surgery and six of 13 (46%) children with suspected renal disease, thereby indicating that there were no significant differences in phagocytic function among these three groups. Of children aged 1 year or less, 75% had abnormal phagocytic function. The significance of this finding is discussed.

Bacteriology of chronic otitis media with effusion.

Samples of middle ear effusions from 102 children with serous and mucoid otitis media were cultured for mycoplasmas and bacteria. No sample yielded mycoplasmas but bacteria were cultured from 48 (47 per cent). Organisms commonly regarded as pathogens were present in 25 samples (Haemophilus influenzae 17, Streptococcus pneumoniae four, other streptococci four). The only sample from which anaerobic bacteria were isolated was from a patient with cholesteatoma.

Motile curved bacilli. Isolation and investigation.

Motile curved bacilli seen in vaginal secretions have been isolated on Columbia agar supplemented with 5% human blood and vitamin K. Growth occurred both anaerobically and in 5% oxygen, but not under more aerobic conditions. There were two distinct groups of these organisms, distinguishable by morphology, biochemical activity, antigenic pattern and susceptibility to metronidazole. All isolates were sensitive to a wide range of antimicrobial agents, with the exception of nalidixic acid and polymyxin. One group was resistant to metronidazole.