Non-sporing anaerobes in certain surgical group of patients.

The magnitude of non-sparing anaerobic (NSA) infections has been defined in the postoperative wounds on colorectum in children (57.1%), general surgery (0%), abdominoperineal and uterocervical operations (11-45%) in gynaecologic and obstetrical cases and perforative peritonitis (25.8-32.3%). Children below the 6 months age group bear less risk of acquiring NSA infection. Under certain situations, metronidazole combats NSA infections in a better way than other antibacterials. The bacteriology of NSA infections has been probed at the species level in the gynaecologic and obstetrical patients. The species of normal cervix (44.6%) are represented in wounds involving abdominal wall (11%), perineum (22.8%) and uterocervix (45.6%) to suggest endogenous infection. Out of the 22 species of NSA isolated, Peptostreptococcus anaerobius, Acidaminococcus fermentans and Peptococcus prevotii are the commonest. Others were Peptococcus niger, Gaffkya anaerobia, Lactobacillus bulgaricus, Actinomyces bovis, Bacteroides oralis, Fusobacterium gonidiaformans and the different species of peptococcus, peptostreptococcus, eubacterium, propionibacterium and fusobacterium. The weight of evidence indicated a pathogenic role of Peptostreptococcus anaerobius and Ruminococcus flavefaciens, in view of their heavy growth. The umbrella of antibacterials reduced Gram-positive anaerobic cocci from 40% to 16%. The facultative anaerobes Staph aureus, Staph epidermidis, Kl pneumoniae and proteus appeared as the exogenous agents of nosocomial infections.

Rapid diagnosis of anaerobic gram-positive cocci by salt tolerance.

The maximum salt tolerance was 2.5% in cases of Peptostreptococcus anaerobius and Peptococcus prevotii, 3% in Ruminococcus albus, 4% in Acidaminococcus fermentans, Peptococcus niger and Megasphaera elsdenii and 5% in Peptococcus magnus. The biochemical tests being largely inactive and time consuming the findings of salt tolerance if combined with those of morphological data provide clue to the rapid identification of Gram-positive anaerobic cocci.

Microflora in postirradiated cancer cervix.

Cases of cancer cervix receiving radiation therapy revealed more anaerobes (50%) in comparison to normal controls (44.6%). The aerobic organisms were suppressed in the former cases (63.6%) in contrast to the latter group (90.7%). Of the anaerobes, the Gram-negative bacilli were more notable (18.1%) in cancer cervix than the normal controls (4.6%). The anaerobes like Peptococcus prevotii (18.1%) and Bacteroides oralis (9%) and the aerobes, Staph aureus (13.6%) and klebsiella (13.6%) were prevalent in cancer cervix. The higher incidence of aerobic and anaerobic organisms in stage III elderly (> 45 years) patients of cancer cervix may necessitate antibacterial therapy.

Non-sporing anaerobes in hospital sepsis.

In comparison to normal controls, the non-sporing anaerobes were often isolated from orodental sepsis (42% to 44.4%), chronic suppurative otitis media (40%), septic abortion (40.3%), uterocervical wound (45.4%), vaginitis (50%) and cancer cervix (50%). This was true (40%) in perforating ulcers of foot in leprosy. These organisms were less frequently noted in abdominal (11%) and episiotomy (22.8%) wounds and leucorrhoea (33.3%). The role of non-sporing anaerobes was also suggested by the high percentage ratio of number of isolates to number of cases and by its primary isolation in moderate to heavy number. Barring the cases of cancer cervix, the aerobic bacteria were the most common (78.8% to 100%) in all other conditions.

Antibacterial susceptibility of anaerobes by agar dilution method.

Of the 9 antibacterials, vancomycin alone at its break-point (optimum blood level) revealed highest (93.3%) efficacy on Gram-positive cocci. The remarkable activity of carbenicillin, chloramphenicol and vancomycin on Gram-positive cocci (95.4 to 96.9%), carbenicillin and chloramphenicol on Gram-positive bacilli (94.8% to 98.2%) and chloramphenicol on Gram-negative bacilli (95.4%) was noted by increasing their concentrations 1.5 to 2.5 times above their break-points. These (and even higher) concentration, however, showed relatively lower efficacy of metronidazole, rifampicin, penicillin, clindamycin and erythromycin on Gram-positive cocci (76 to 84.1%), rifampicin, tetracycline, erythromycin, clindamycin and vancomycin on Gram-positive bacilli (81 to 87.9%) and clindamycin, metronidazole, rifampicin and carbenicillin in Gram-negative bacilli (72.7 to 84%). By and large, rifampicin, chloramphenicol and carbenicillin are also quite effective (72.1 to 75.1%) at lower concentration.

Ischaemic mouse thigh model for evaluation of pathogenicity of non-clostridial anaerobes.

A mouse thigh model has been devised in which the growing culture of non-clostridial anaerobe in the ischaemic tissue produces inflammatory swelling and death. The swelling of the right thigh served as an index of pathogenicity of the test strain in comparison to the negatively reacting left thigh which received injection of the control strain of Bifidobacterium infantis. Actinomyces naeslundii exceptionally caused death in all animals within 24 h. Mortality and thigh swelling were pronounced (greater than 75%) in case of Fusobacterium gonidiaformans and Propionibacterium acnes but less (less than 50%) in Acidaminococcus fermentans. High (less than 75%) rate of thigh swelling was also encountered in case of Bacteroides oralis, Bacteroides corrodens, Fusobacterium necrophorum, Fusobacterium prausnitzii, Fusobacterium plauti, Peptococcus prevotii, Streptococcus intermedius, Eubacterium lentum and Propionibacterium freudenreichii ss. shermanii.