Anaerobic Gram-positive Cocci Research Articles

Bacteria isolated from the duodenum, ileum, and cecum of young chicks.

Facultatively anaerobic and strictly anaerobic bacteria colonizing the intestinal tracts of 14-day-old chicks fed a corn-based diet were enumerated, isolated, and identified. Colony counts from anaerobic roll tubes (rumen fluid medium) or aerobic plates (brain heart infusion agar) recovered from homogenates of the duodenum, upper and lower ileum, and cecum varied appreciably among samples from individual birds. Anaerobic and aerobic counts from the duodenum and ileum were similar. Anaerobic counts were highest from the cecum (0.7 X 10(11) to 1.6 X 10(11)/g of dry tissue) and exceeded aerobic plate counts by a factor of at least 10(2). Facultatively anaerobic groups (Streptococcus, Staphylococcus, Lactobacillus, and Escherichia coli) comprised the predominant flora of the duodenum and ileum, although large numbers of anaerobes (9 to 39% of the small intestine isolates), represented by species of Eubacterium, Propionibacterium, Clostridium, Gemmiger, and Fusobacterium, were also recovered. Strict anaerobes (anaerobic gram-positive cocci, Eubacterium, Clostridium Gemmiger, Fusobacterium, and Bacteriodes) made up nearly the entire microbial population of the cecum. Scanning electron microscopy of the intestinal epithelia of chicks revealed populations of microbes on the duodenal, ileal, and cecal mucosal surfaces.

In vitro activity of cefaclor against aerobic and anaerobic bacteria.

Cefaclor (CCL), a new cephalosporin, was tested in vitro against 602 (271 anaerobic and 331 aerobic) clinical isolates in comparison with cephalothin, cefazolin, cephradine, and cefamandole. Sixteen micrograms of CCL per ml inhibited 68% of all aerobes tested and 80% of the 211 enteropathogenic organisms (Escherichia coli, Salmonella, and Shigella) isolated from cases of infantile diarrhoea. CCL inhibited 88% of gram-positive anaerobic cocci and 72% of Bacteroides other than B. fragilis at a concentration of 16 mug/ml. B. fragilis and Clostridia were resistant to CCL. Increased inoculum of E. coli from 10(5) to 10(9) increased the minimal inhibitory concentration of CCL and cefamandole by fourfold against 7 of the 64 strains tested. All seven were beta-lactamase negative. No antimicrobial synergism was noted between CCL and penicillin. The in vitro efficacy of CCL, an oral cephalosporin, against enteropathogenic E. coli, if proven safe, may be tested in vivo against such infections.

Microbiological investigation of Bartholin's gland abscesses and cysts

Percutaneous aspirates from intact Bartholin's gland cysts (12) and abscesses (34) were examined for bacteria and genital mycoplasmas. Aspirates from 10 of the 12 patients with Bartholin's gland cysts were sterile. Aspirates from the other two cysts contained organisms that are part of the vaginal microbial flora. Of the 34 abscesses, 24 (70.6 per cent) contained bacteria. Eight abscesses contained gram-negative rods in pure culture and four contained gonococci in pure culture. Twelve abscesses contained one or more vaginal organisms including anaerobic gram-negative rods (eight isolates), anaerobic gram-positive cocci (eight), Staphylococcus epidermidis (four), and microaerophilic streptococci (three). Although most of the patients had genital mycoplasmas isolated from vaginal cultures, Mycoplasma hominis was isolated from only one and Ureaplasma urealyticum from none of the aspirates.

Comparative susceptibility of anaerobic bacteria to ticarcillin, cefoxitin, metronidazole, and related antimicrobial agents.

The in vitro antimicrobial activity of two newer agents, ticarcillin and cefoxitin, against 204 recent clinical isolates of anaerobic bacteria was determined by an agar dilution technique, and compared to their related compounds carbenicillin, cephalothin, and penicillin, as well as metronidazole, clindamycin, and chloramphenicol. Ticarcillin was similar to carbenicillin, and cefoxitin was more active than cephalothin. At readily achievable blood concentrations of each antimicrobial agent, ticarcillin was slightly less active than clindamycin against Bacteroides fragilis. Cefoxitin was superior to cephalothin and penicillin against B. fragilis. Penicillin remained highly active against all obligate anaerobes other than B. fragilis. Metronidazole, while highly effective against B. fragilis and Clostridium perfringens, was only intermediately effective against anaerobic gram-positive cocci and relatively inactive against nonsporulating anaerobic gram-positive bacilli. Further evaluation of the clinical efficacy of ticarcillin, carbenicillin, and cefoxitin against anaerobic infections is indicated.

BACTERIOLOGY OF ASPIRATION PNEUMONIA IN CHILDREN

The bacteriology of aspiration pneumonia in institutionalized children and adults was determined by transtracheal aspiration. Forty-three patients were studied, including 10 adults and 33 children ranging from 2 months to 18 years in age (average 8.5 years). Ignoring Staphylococcus epldermldis, the 43 aspirates yielded 85 aerobic and 86 anaerobic isolates, demonstrating the polybacterial etiology of the infection. Anaerobic bacteria were isolated from 30 children (91%) and from 9 of 10 adults. The predominant anaerobes were Bacteroides melaninogenicus (18 isolates), Fusobacterium sp. (10), and anaerobic and microaerophilic gram-positive cocci (21); there were 8 isolates of B. fragills. These organisms were proportionately distributed between children and adults except for relatively more B. melaninogenicus in children and more B. fragilis in adults. Pneumococci (10 isolates), group A streptococci (8) and Haemophilus influenzae (2) were recovered only from children and among 11 Eacherichis coli isolates, 10 were from children (mostly under 6 years of age). The Klebsiella-Enterobacter-Serratia group, Proteus, Pseudomonas and alpha-hemolytic streptococci were proportionately more common in adults than in children. All subjects recovered with appropriate therapy. Anaerobic bacteria clearly play a role in aspiration pneumonia in children as well as in adults. The differences in aerobic bacteriology cited require different therapeutic approaches.

Quantitative microflora of the vagina

This study enumerated the predominant vaginal flora in 25 healthy patients: 18 prenatal (six with and 12 without gonorrhea) and seven nonpregnant without gonorrhea. All 25 patients had aerobes and 19 of the 25 had anerobes isolated in titers of ≥105 colony-forming units (CFU per milliliter.) The most frequently isolated microorganism was the lactobacillus (aerobic and anaerobic species) followed by C. vaginale, viridans streptococci, anaerobic gram-positive cocci, and Bifidobacterium sp. Bacteroides fragilis was not isolated. There were no significant differences in the frequency of isolation of any specific microorganism or bacterial counts between pregnant and nonpregnant women or between pregnant women with and without gonorrhea (p > 0.05), except pregnant patients had significantly higher total facultative counts associated with significantly lower anaerobic lactobacilli counts and higher C. vaginale counts (p < 0.01) than in nonpregnant patients.

Aerobic and anaerobic flora of the cervix during pregnancy and the puerperium

Comparison of species of bacteria isolated from patients with endometritis with species isolated from normal pregnant and nonpregnant women suggests that bacteria causing infections are indigenous to the genital tract. However, complete studies of the flora of pregnant women, especially anaerobic flora, are lacking. Aerobic and anaerobic cultures of the endocervix were obtained from women in all trimesters of pregnancy and at three days and six weeks post partum. The incidence of occurrence of each species of bacteria and the average number of different species per culture were determined for each period. The most prevalent organisms in each period were aerobic gram-positive rods and cocci and anaerobic gram-positive cocci. The average number of species of aerobic bacteria per culture remained approximately the same in each culture period. The average number of anaerobic species per culture decreased as pregnancy progressed, peaked on the third postpartum day, and at six weeks post partum returned to a level similar to that of the first trimester.

Evaluation of the sodium polyanethol sulfonate disk test for the identification of Peptostreptococcus anaerobius

The previously reported sodium polyanethol sulfonate disk test for the identification of Peptostreptococcus anaerobius (Graves et al., 1974) was evaluated, with modifications. Three bands of brucella agar, three inoculum sizes, and two inoculum sources were compared. Nine stock cultures of P. anaerobius (eight normal flora isolates and ATCC 27337) and 16 fresh clinical isolates were used. All cultures of P. anaerobius showed inhibition zones of 12 to 30 mm in diameter, regardless of test conditions. Out of 103 clinical isolates of other species of anaerobic gram-positive cocci tested, only two had an inhibition zone size in this range (one P. micros of 11 studied had a zone of 12 mm and one P. prevotii of 14 studied had a zone of 16). The test had an overall accuracy of 98% in the identification of P. anaerobius from clinical specimens. Since P. anaerobius accounts for one-fifth to one-third of all anaerobic gram-positive cocci encountered in clinical specimens, this simple and rapid technique can be very useful for presumptive identification.

Ureolytic bacteria in sheep rumen.

Estimates were made of the numbers of viable bacteria in the rumens of sheep receiving different rations. Representative colonies were isolated and tested for urease production. Some urease-positive isolates were characterized and identified. The ureolytic activities of the urease-producing isolates were determined and compared with the activity of rumen fluid. The rations fed to the sheep did not exert a significant influence on the relative numbers of the urease-producting organisms in the rumen. No obligately anaerobic ureolytic bacteria were found. All urease-positive isolates were facultatively anaerobic, Gram-positive, catalase-positive cocci. Out of ten isolates, nine were identified as Staphylococcus saprophyticus and one as Micrococcus varians. The total urease activity of the different isolates based on the lowest numbers in which they were present in the rumen, compared favourably with the urease activity of rumen fluid. The facultatively anaerobic Gram-positive cocci were probably responsible for a large proportion of the urease activity of the rumen fluid. Conditions prevailing in the rumen were found to be conducive to urease production by the isolates tested.

Bacterial interference by Streptococcus salivarius.

A strain of streptococcus salivarius, recognized in a throat culture because of its inhibition of the growth of a species of Corynebacterium, was studied in vitro to determine its antagonistic effects agains various other bacteria. It was found to be inhibitory to anaerobic Gram-positive cocci, streptococci belonging to Lancefields groups A, C, F, and G, and Corynebacterium diphtheriae, C. hofmanii, and C. xerosis.

Isolation and identification of rumen bacteria capable of anaerobic phloroglucinol degradation.

Eight strains of rumen bacteria capable of degrading phloroglucinol (1,3,5-trihydroxybenzene) under anaerobic conditions were isolated from enrichment cultures of the bovine rumen microflora established in a prereduced medium containing 0.02 M phloroglucinol. Five of the strains were facultatively anaerobic Gram-positive streptococci which were identified as Streptococcus bovis. Three strains of obligately anaerobic Gram-positive cocci were assigned to the genus Coprococcus. Anaerobic cultures of the Streptococcus bovis strains in a 40% rumen fluid medium initially containing 0.02 M phloroglucinol degraded 50-80% of the substrate within 2 days, whereas cultures of the Coprococcus strains degraded more than 80% of the substrate under the same conditions. The Streptococcus bovis strains were incapable of degrading phloroglucinol in brain heart infusion or in the medium of de Man, Rogosa, and Sharpe (MRS broth) incubated aerobically.

Lincomycin and clindamycin: their role in chemotherapy of anaerobic and microaerophilic infections.

Lincomycin is active against the following anaerobic organisms: anaerobic gram-negative bacilli such as Bacteroides species and Fusobacterium species; anaerobic gram-positive nonspore-forming bacilli such as Propionibacterium, Eubacterium, and Actinomyces species; anaerobic and microaerophilic gram-positive cocci such as Peptococcus species, Peptostreptococcus species and microaerophilic streptococci; and Clostridium species. Clindamycin, 7(S)-chloro, 7-deoxylincomycin is four to eight times as active as lincomycin in vitro, against the above mentioned anaerobes. Clindamycin is available in oral dosage forms and is just now being made available as clindamycin phosphate, a new injectable form of clindamycin.

Bacteriology and treatment of primary lung abscess.

A prospective study of bacteriology and therapeutic outcome in 26 cases of primary lung abscess is reported. Bacteriologic results were based on percutaneous transtracheal aspirates obtained before antimicrobial therapy. Anaerobic bacteria were recovered from 24 patients. The principal isolates were Fusobacterium nucleatum, Bacteroides melaninogenicus, and anaerobic gram-positive cocci. Bacteroides fragilis, of interest for its unique antibiotic susceptibility pattern, was recovered from 4 patients. Aerobic or facultative bacteria were present in 10 patients but were the exclusive isolates in only 2. Antimicrobial therapy was selected on the basis of the bacteriologic findings. This was judged successful in all cases, although 2 patients died from concurrent conditions before their pulmonary infection was cured.

BACTERIOLOGY OF EMPYEMA

The bacteriology of empyema fluid was studied in three hospitals equipped with anaerobic research laboratories. Acceptable cases were restricted to adult patients who had not received antimicrobial therapy nor undergone previous thoracic surgery. Anaerobic bacteria were recovered in 63 of 83 (76%) cases studied, and these were the exclusive isolates in 29 (35%). The predominant microorganisms, in order of prevalence, were anaerobic or microaerophilic gram-positive cocci, Staphylococcus aureus, Fusobacterium nucleatum, Bacteroides melaninogenicus, B. fragilis, clostridia, Escherichia coli and Pseudomonas aeruginosa. These results demonstrate the need for careful transport and processing of pleural-fluid specimens to ensure recovery of oxygen-sensitive forms.

Isolation of peptococci and peptostreptococci in developing human dental plaque by maintaining continuous anaerobiosis.

Plaque samples of 2, 5, 7 and 12 days were obtained under complete anaerobiosis with a special technique from the labial surfaces of the upper incisor teeth of six subjects. the samples were primarily assayed for their content of grampositive bacteria; actinomyces, eubacteria, lactobacilli, corynrbacteria, nocardia, propionibacteria, peptococci, peptostreptococci, and streptococci. At day 2 streptococci, corynebacteria and nocardia predominated, but after 5 days also anaerobic gram-positive cocci and rods were found. 15 strains of these cultivable gram-positive anaerobic cocci were investigated further with regard to morphology, biochemical reactions and fermentation products. Seven of these organisms resembled Peptostrepto-coccus intermedius and four of these strains were probably Peptostreptococcus anaerobius. One appeared to belong to Peptococcus magnus and the remaining strains could be considered as Peptococcus variabilis.

Pectin-fermenting bacteria isolated from the bovine rumen.

Thirty-two strains of pectin-fermenting rumen bacteria were isolated from bovine rumen contents in a rumen fluid medium which contained pectin as the only added energy source. Based on differences in morphology and the Gram stain, 10 of these strains were selected for characterization. Two strains were identified as Lachnospira multiparus, four strains were identified as Butyrivbrio fibrisolvens, and three strains were identified as Bacteroides ruminicola. Characteristics of the remaining strain did not correspond with any previously described species. It was a gram-positive anaerobic coccus, 1.0 to 1.2 mum in diameter, and occurred primarily as single cells or diplococci. The strain fermented pectin rapidly but showed little or no growth on any other energy sources tested. The only detectable end products were acetic acid and gas, a portion of which was identified as hydrogen. Although the physiological characteristics of this organism differ markedly from other described species, it has been placed in the genus Peptostreptococcus on the basis of morphology, Gram stain, relations to oxygen, and the occurrence of cell division in only one plane. End products of fermentation are somewhat similar to those of the cellulolytic ruminococci. Eight previously characterized strains of cellulolytic bacteria isolated in nonselective media were unable to ferment pectin, whereas ten strains of hemicellulolytic rumen bacteria, eight of which were isolated with a xylan medium, showed considerable variation in this characteristic.

Investigations on the microbiology of cellulose utilization in domestic rabbits.

SUMMARY: Cellulolytic iodophilic cocci have been isolated in significant numbers from rabbit caecal contents. Seven strains of the anaerobic Gram-positive cocci have been isolated on seven separate occasions from rabbits obtained from different sources and maintained on various diets. No other cellulolytic bacteria have been observed in cultures inoculated with high dilutions of caecal contents, suggesting that the isolated cocci are the most important agents of cellulose digestion in the caecum. Of the carbohydrates tested the caecal cocei utilize only cellulose and cellobiose. The products of cellulose fermentation include acetic acid, succinic acid, a trace of formic acid, ethanol, CO2 and H2.