Isolation and identification of anaerobic bacteria from ovine foot rot in Spain

A microbiological study was made of 125 Merino sheep showing clinical signs of foot rot. A total of 435 strictly anaerobic strains were isolated, belonging to the following genera: Bacteroides, Peptostreptococcus, Tissierella, Fusobacterium, Megasphaera, Eubacterium, Acidaminococcus, Clostridium, Peptococcus and Propionibacterium. Of the 35 species obtained, the following were found in more than 10 per cent of animals sampled: Bacteroides nodosus, B putredinis, B buccae, B ruminicola subspecies brevis, Tissierella praeacuta, Peptostreptococcus anaerobius and Megasphaera elsdenii. Six culture media were used for isolation. Agar brucella and agar brucella enriched with G-N anaerobe supplement proved to be the most efficient for isolating anaerobic bacteria.     

Occurrence of anaerobic bacteria in diseases of the dog and cat.

A survey for anaerobic bacteria was conducted in 314 clinical specimens from dogs and cats. A total of 187 anaerobic isolates in pure and mixed culture were isolated from 111 of the specimens that contained anaerobic bacteria. Common isolated included Actinomyces (9.1%), Clostridium perfringens (19.3%), other Clostridium spp (11.2%), Peptostreptococcus anaerobius (7.5%), Bacteroides melaninogenicus (13.4%), other Bacteroides spp (17.6%), and Fusobacterium necrophorum (5.3%). Anaerobic bacteria were involved in serious lesions that often were life threatening to the animals. Antibiotic susceptibility data indicated that the lincomycin family, the penicillin family, chloramphenicol, and cephaloridine are preferred drugs for treatment of anaerobic infections. Data from the survey were used in formulation of a table to aid practitioners in clinical diagnosis of disease caused by anaerobes. Clostridium perfringens was isolated in large numbers from five of six dogs with a clinical diagnosis of canine hemorrhagic gastroenteritis and from one cat with hemorrhagic diarrhea. Experimental infections were induced in rats, using caine feces as inoculum. Induced lesions contained aerobic and anaerobic bacteria similar to those bacteria isolated in the clinical survey, indicating that feces may serve as a major source of these bacteria in clinical infections of the dog.     

Oral associated bacterial infection in horses: studies on the normal anaerobic flora from the pharyngeal tonsillar surface and its association with lower respiratory tract and paraoral infections

Two hundred and seventy bacterial isolates were obtained from the pharyngeal tonsillar surface of 12 normal horses and 98 obligatory anaerobic bacteria were characterised. Of these, 57 isolates belonging to 7 genera (Peptostreptococcus (1); Eubacterium (9); Clostridium (6); Veillonella (6); Megasphera (1); Bacteroides (28); Fusobacterium (6)) were identified, and 16 of these were identified to species level (P. anaerobius (1); E. fossor (9); C. villosum (1); B. fragilis (1); B. tectum (2); B. heparinolyticus (2)). Three hundred and twenty isolates were obtained from 23 samples from horses with lower respiratory tract (LRT) or paraoral (PO) bacterial infections. Of the 143 bacteria selected for detailed characterisation, obligate anaerobes accounted for 100 isolates, facultative anaerobes for 42 isolates and obligate aerobes for one isolate. Phenotypic characterisation separated 99 of the isolates into 14 genera. Among the obligately anaerobic species, Gram-positive cocci including P. anaerobius comprised 25% of isolates, E. fossor 11% and other Gram-positive rods (excluding Clostridium sp.) 18% of isolates. The Gram-negative rods comprised B. fragilis 5%, B. heparinolyticus 5%, asaccharolytic pigmented Bacteroides 3% and other Bacteroides 13%, while a so-far unnamed species of Fusobacterium (7%), and Gram-negative corroding rods (3%) were isolated. Among the facultatively anaerobic isolates, S. equi subsp. zooepidemicus accounted for 31% of isolates, followed by Pasteurella spp. 19%, Escherichia coli 17%, Actinomyces spp. 9%, Streptococcus spp. 9%. Incidental facultative isolates were Enterococcus spp. 2%, Enterobacter cloaceae 2%, Actinobacillus spp. 2% and Gram-negative corroding rods 5%. On the basis of the similarities (as determined by DNA hybridization data and/or phenotypic characteristics) of some of the bacterial species (e.g. E. fossor and B. heparinolyticus) isolated from both the normal pharyngeal tonsillar surfaces and LRT and PO diseases of horses, it is considered that the most likely source of bacteria involved in these disease processes is flora from the oral cavity.     

Isolation and identification of intestinal bacteria from Japanese tree frog (Hlya japonica) with the special reference to anaerobic bacteria.

The bacteria in the large intestines of eight Japanese tree frogs (Hlya japonica) were enumerated by using an anaerobic culture system. The microorganisms at approximately 3.1 x 10(9) bacteria per g (wet weight) of intestinal contents were present in the intestine of all the frogs tested. No difference of the total bacteria in the frog intestine was observed between two different incubation-temperatures (room temperature and 37 degrees C). Eleven genera and 16 species were isolated from the frog intestine. In most frogs, Bacteroides (B.) caccae and B. vulgatus were detected as the predominant organisms. Escherichia coli was also present in greater numbers in the intestine. Other bacteria isolated at high dilutions were strict anaerobes, including Fusobacterium and Clostridium. Enterococcus faecalis was frequently isolated from the frog intestine. However, four genera of Bifidobacterium, Eubacterium, Peptostreptococcus, and Lactobacillus were not isolated from the frog intestine.     

The obligate and facultatively anaerobic bacterial flora of the normal feline gingival margin

Samples from the gingival margins of 14 cats considered normal on clinical examination were cultured for facultative and obligate anaerobic bacteria. All mouths were free from any gingival marginal inflammation and tartar build-up; all cats were between 6 and 12 months of age. A mixed growth was obtained from all samples. The mean number of bacterial species per sample was 10.7 with a range of 7-16 isolates. Of the 150 isolates processed, 109 (72.66%) were obligate anaerobes. Of the facultatively anaerobic species, Actinomyces (including A. viscosus, A. hordeovulneris and A. denticolens) comprised 12%, Pasteurella multocida 9.33% of isolates and Propionibacterium species 6% of all isolates. Gram-negative bacilli belonging to the genera Bacteroides and Fusobacterium were isolated from 12 of the 14 samples, and comprised 77% of the obligate anaerobes isolated. Clostridium villosum comprised 10.1% of obligately anaerobic isolates, Wolinella species made up 6.42%, while 4.58% were Peptostreptococcus anaerobius. The most commonly isolated obligately anaerobic species was C. villosum and the most commonly isolated facultatively anaerobic species was P. multocida. These findings show a bacterial flora of the normal feline mouth which is very similar in composition to that of cat fight abscesses and feline pyothorax.     

Changes in prevalence and susceptibility of obligate anaerobes in clinical veterinary practice

Of 3,133 clinical specimens obtained from domestic animals, 26% contained species of bacteria that were obligate anaerobes. Members of the genera Bacteroides, Fusobacterium, and Peptostreptococcus accounted for 77% of the isolates. On the average, 2 species of obligate anaerobes were found in each specimen, usually admixed with facultatively anaerobic bacteria. Of those specimens containing an obligate anaerobe, 20% contained one isolate that was resistant to penicillin, ampicillin, and cephalothin. These resistant isolates belonged to the genus Bacteroides, the most common being Bacteroides fragilis. Approximately one third of these penicillin-resistant isolates was resistant to tetracycline as well. All isolates were susceptible to chloramphenicol, tetracycline (excluding penicillin-resistant Bacteroides), metronidazole, and clindamycin.     

Suitability of the broth-disk elution test for evaluating susceptibility of obligate anaerobes to trimethoprim-sulfonamides

Species of anaerobic bacteria isolated from clinical veterinary specimens were tested for susceptibility to trimethoprim-sulfonamides by the broth-disk elution technique. Three different media were used for each organism: prereduced anaerobically sterilized (PRAS) brain-heart infusion broth (BHI), thioglycollate broth, and a semidefined PRAS medium. Susceptibility results from these media were compared with those determined by interpreting the minimal inhibitory concentration obtained using an agar dilution technique. Results from broth-disk testing in semidefined medium agreed in 68.7% of the cases, in 53.7% for thioglycollate broth, and in 36.9% for BHI. The greatest deviation between techniques occurred with isolates belonging to the genus Bacteroides, followed by those of the genus Clostridium and those of the genus Fusobacterium. This deviation was directly proportional to increasing concentrations of thymidine in the BHI and thioglycollate broths but not with the semidefined medium. We conclude that the broth-disk elution method for measuring susceptibility of obligate anaerobes to trimethoprim-sulfonamides is unsuitable.     

Comparative bacteriological studies on summer mastitis in grazing cattle and pyogenes mastitis in stabled cattle in Denmark.

A total of 143 secretions from clinical cases of summer mastitis (SM) in grazing cattle and from 89 cases of pyogenes mastitis (PM) in stabled cattle were examined bacteriologically. The typical bacteriological finding was a mixed flora in which the predominant organisms were Actinomyces pyogenes (SM-70%, PM-85%), Peptostreptococcus indolicus (54%, 54%), a microaerophilic coccus (Stuart-Schwan coccus) (26%, 25%), Fusobacterium necrophorum biovar B (22%, 12%), Bacteroides melaninogenicus (20%, 9%) and Streptococcus dysgalactiae (21%, 5%). All except six cases occurred in non-lactating animals or within three weeks after parturition. The majority of animals (about 90%) had only one quarter affected and no differences in quarter distribution were observed between the two groups.     

The identification and antimicrobial susceptibility of anaerobic bacteria from pneumonic cattle lungs.

One hundred and forty-four lungs obtained postmortem from cattle with pneumonia were cultured for anaerobic bacteria. Forty-five lungs yielded 73 anaerobic isolates belonging to 20 species. The number of isolations of anaerobes from acute fibrinous or suppurative bronchopneumonias (32.5%) was slightly lower than from similar chronic bronchopneumonias (36.5%). Anaerobes were not recovered from 15 lungs showing macroscopic changes not of bacterial origin, nor from 13 healthy lungs. The predominant genera isolated were Bacteroides, Peptococcus, Fusobacterium and Clostridium. The most common species were P. indolicus (15 isolates), B. asaccharolyticus (nine), F. necrophorum (six), C. perfringens (four) and B. fragilis (four). There was a significant correlation between the presence of Corynebacterium pyogenes (p less than 0.001) or Escherichia coli (p less than 0.01) and the presence of anaerobes in the lungs. The isolated anaerobic bacteria were generally susceptible to ampicillin, penicillin G, cefoxitin, cephalothin, clindamycin, chloramphenicol, erythromycin, tetracycline and metronidazole. The B. fragilis and C. perfringens isolates showed multiple antibiotic resistance, and five P. indolicus isolates were resistant to tetracycline.     

Bacteria in enteric lesions of cattle

Thirty-nine species of bacteria were isolated from or demonstrated in the abomasal and small and large intestinal mucosa of 23 adult cattle and 41 calves and identified. The bacteria isolated were related to the gross and microscopical lesions. Campylobacters, Clostridium perfringens type A, C sordellii, Actinobacillus lignieresii, Fusobacterium necrophorum, Mycobacterium paratuberculosis, Aeromonas hydrophila and Escherichia coli were all associated with specific lesions. The relationship of other bacteria such as Bacillus licheniformis, Branhamella catarrhalis and Bacteroides vulgatus to lesions in which they were found was discussed. It was concluded that some of the bacteria could be responsible for the lesions in which they were found. However, proof of this supposition could only be obtained by experimental infections of non-immune cattle with pure cultures.     

Aetiology of caprine footrot in Extremadura region, Spain

The present study reports on the location of major foci of footrot in goats in the Extremadura region of Spain by the determination of locally occurring strictly anaerobic microorganisms involved in the pathogenesis and development of this disease. The most commonly isolated microorganisms belonged to the genera Dichelobacter, Fusobacterium, Porphyromonas and Prevotella; these were found in conjunction with other species of minor importance. The species most frequently isolated were Fusobacterium necrophorum (40%), Dichelobacter nodosus (31.7%), Porphyromonas asaccharolytica (21.1%) and Prevotella melaninogenica (12.9%). Virulence factors identified in the isolated microorganisms included haemolysins, elastases and lecithinases, which enabled the organisms involved to initiate and/or aggravate the disease. Serotyping was performed for Dichelobacter nodosus isolates, since this species is responsible for triggering the process of infection. A and C were the most frequently isolated serovarieties (representing 40.7% and 25.9% of the cases, respectively).     

Osteomyelitis in dogs and cats caused by anaerobic bacteria

Localised osteomyelitis was diagnosed in 2 dogs and 2 cats. The disease was caused by fight wounds in 3 cases. Radiographic examination demonstrated a circumscribed zone of cortical bone lysis, sequestra and periosteal new bone. Each case was treated surgically by sequestrectomy and debridement. Infection was due mainly to anaerobic bacteria. The pathogenic bacteria isolated from the lesions of dogs were Actinomyces viscosus, Fusobacterium nucleatum and Bacteroides spp, and from the lesions in cats were Clostridium villosum , Peptostreptococcus anaerobius, Wolinella recta and Bacteroides gingivalis. As all the bacteria were sensitive to penicillin, each case was treated with penicillin and by irrigation of the wound. This resulted in resolution of the disease, within 4 weeks, in all cases.     

鸡肠道菌基因组DNA的RAPD分类的研究

本文以7种鸡肠道菌为研究对象，分别提取基因组DNA，利用随机扩增多态性DNA（RAPD）技术对其基因组进行DNA分析，筛选出一系列随机引物，能在7种肠道细菌中有较好的多态性，可用作分子标记鉴别这7种肠道菌。     

Aetiological agents of necrobacillosis in captive wallabies

In a series of 27 wallabies (Macropus rufogriseus) with necrobacillosis, 14 animals were affected in the face, nine in the leg and six in the internal organs, two being affected in more than one site. Fusobacterium necrophorum was the predominating organism, occurring in 69 per cent of lesions, usually in heavy and occasionally in pure culture. Bacteroides species (six in all), often in considerable numbers, were found in 48 per cent of lesions, and F nucleatum in 14 per cent. Aerobes or facultative anaerobes, usually in small numbers, were present in 59 per cent of lesions. The organisms isolated often varied considerably from one part of the lesion to another.     

Isolation and characterisation of bacteria from pyothorax (empyaemia) in cats

Samples from 19 cases of feline empyaemia were examined. All cases had no prior treatment and specimens were collected by thoracocentesis after preparation of the skin as for aseptic surgery. Of the 87 bacterial strains isolated, 70 (80.5%) were anaerobes and 17 (19.5%) were facultative anaerobes. Fourteen cases contained mixtures of anaerobes and facultative anaerobes, and five contained anaerobes only. Bacteroides was the most commonly isolated genus (42.5% of all isolates). Clostridium villosum (16.1%) was the most frequently isolated bacterial species followed by Peptostreptococcus anaerobius and Pasteurella multocida (each 12.6%). The most commonly isolated anaerobic species was Clostridium villosum sp.nov. (20% of anaerobic isolates and 16.1% of all isolates) and Pasteurella multocida was the most commonly isolated facultatively anaerobic species (64.7% of facultative isolates and 12.6% of all isolates).     

Central Nervous System Infection Associated With Anaerobic Bacteria in Two Dogs and Two Cats

Central nervous system (CNS) infection caused by anaerobic bacteria (including Bacteroides, Fusobacterium, Peptostreptococcus, and Eubacterium) was diagnosed in two dogs and two cats. In one dog there was extensive meningomyeloencephalitis, presumably the result of hematogenous spread of bacteria from lung abscesses and bacterial endocarditis. Subdural empyema of unknown origin was found in a second dog and two cats. Clinical signs in all four animals included mental depression and focal neurologic deficits, without fever.     

Bacterial infection of the lower respiratory tract in 34 horses

OBJECTIVE: To investigate associations between the bacteriology and aspects of history, clinical presentation, outcome and pathology of lower respiratory tract disease of 34 horses. PROCEDURE: Detailed aerobic and anaerobic bacteriological investigations were performed on clinical specimens from horses with pneumonia, lung abscessation and necrotic pneumonia with or without pleurisy in an attempt to identify those bacteria that might contribute to the initiation and progression of infection. RESULTS: Bacteria were cultured from 33 of the 34 horses. In ten cases, only aerobic/facultatively anaerobic isolates were cultured while aerobic/facultatively anaerobic bacteria and obligately anaerobic bacteria were isolated in the other 23 cases. Moderate to large numbers of anaerobic bacteria were isolated only when the estimated duration of illness was at least five days. Bacteria were not cultured from 12 of the pleural fluid samples but were always cultured from pulmonary samples (either transtracheal aspirates from live horses or pulmonary lesions at necropsy). Streptococcus equi subsp zooepidemicus was isolated in the three cases where only one bacterial species was cultured. In the other 30 cases, multiple species were isolated. These included most often and in greatest numbers, Streptococcus equi subsp zooepidemicus, Pasteurellaceae, Escherichia coli, anaerobic cocci, Eubacterium fossor, Bacteroides tectum, Prevotella heparinolytica, Fusobacterium spp, and pigmented members of the genera Prevotella and Porphyromonas. Aerobic/facultatively anaerobic organisms were isolated from 97% of horses, while obligately anaerobic organisms were cultured from 68% of horses. CONCLUSION: There was no association between the isolation of any specific bacterium and the outcome of disease. However, obligately anaerobic bacteria (such as anaerobic cocci, Bacteroides tectum, P heparinolytica and Fusobacterium spp) and the facultatively anaerobic species Escherichia coli, were recovered more commonly from horses that died or were euthanased than from those that survived. There was an association between failure of horses to recover from pleuropneumonia and delay in diagnosis and initiation of treatment.     

Summer mastitis in heifers: a bacteriological examination of secretions from clinical cases of summer mastitis in Denmark

A total of 166 samples of secretions collected from Danish heifers suffering from clinically diagnosed summer mastitis were examined bacteriologically. One hundred and sixty three samples yielded positive findings whereas no growth was obtained from 3 specimens. The majority of samples revealed a mixed flora in which the predominant components were Actinomyces pyogenes, Peptostreptococcus indolicus, a microaerophilic coccus (Stuart-Schwan coccus), Fusobacterium necrophorum, Bacteriodes melaninogenicus and Streptococcus dysgalactiae. Pure cultures were recovered in only 7% of cases. P. indolicus was isolated from 875 of the cases, a microaerophilic coccus from 84%, A. pyogenes from 72%, Fusobacterium necrophorum from 52%, Str. dysgalactiae from 37%, B. melaninogenicus from 33% and various unidentified obligate anaerobic Gram-negative rods from 31%. The results confirm the complex bacterial aetiology of summer mastitis.     

Comparative in vitro susceptibility of Bacteroides and Fusobacterium isolated from footrot in sheep to 28 antimicrobial agents

The agar dilution method was used to determine the bacteriostatic activity of 28 antimicrobial agents against 141 strains to the genus Bacteroides and 29 strains from the genus Fusobacterium. All organisms were isolated from clinical cases of ovine footrot. The strains were isolated from 125 Merino sheep, over a period of 2 years, from January 1987 to December 1988. The three ureidopenicillins studied (azlocillin, mezlocillin and piperacillin) proved to be the most effective antimicrobial agents. Chloramphenicol, metronidazole and tinidazole effectively inhibited the growth of Bacteroides spp., while phosphomycin was active against Fusobacterium spp.     

Bacteroides species from the oral cavity and oral-associated diseases of cats

One hundred and sixty-seven strains of Bacteroides were isolated from 71 subcutaneous fight-wound abscesses of cats, 21 cases of feline pyothorax, normal gingival margins from 10 cats and 6 cases of feline gingivitis. Bacteroides species constituted (as a proportion of all anaerobic isolates examined) 44.5% from subcutaneous abscesses, 33.7% from pyothoraxes, 37.5% from normal gingiva and 27.7% from diseased gingiva. Bacteroides tectum comprised 43.7% or 73 of 167 strains, followed by the black- or brown-pigmented asaccharolytic feline species of B. gingivalis, B. salivosus and Group B, comprising 32.3% or 54 of 167 strains. B. heparinolyticus (some 10% or 17 of 167 strains) was the next most common species described. The remainder consisted of two strains of B. fragilis and 21 unspeciated strains. Bacteroides tectum was frequently isolated from subcutaneous abscesses (43.7%) and pyothoraxes (46.6%), and it constituted some 33% of anaerobic isolated from normal gingiva. Bacteroides heparinolyticus was more commonly encountered in purulent lesions (abscesses and pyothoraxes) than in the oral cavity.