Isolation of Actinomyces hyovaginalis from sheep and comparison with isolates obtained from pigs

Actinomyces hyovaginalis, an organism initially described from pigs, was recovered from nine sheep and a moufflon. Further strains of A. hyovaginalis were recovered from five samples from pigs over the same period. 16S rRNA sequencing and extensive phenotyping demonstrated high similarity between the ovine and porcine isolates; however differences with respect to erythritol, adonitol and l-arabitol fermentation were detected. Ovine isolates were made from various sample sites including abscesses and highlight the importance of the accurate identification of the various coryneform isolates which affect sheep. A. hyovaginalis can be added to the growing list of coryneforms which can cause disease in sheep including Corynebacterium pseudotuberculosis, Trueperella pyogenes and Arcanobacterium pluranimalium.     

Biochemical and serological properties of Actinobacillus pleuropneumoniae biotype 2 strains isolated from swine

The biochemical and serological properties of 21 strains of Actinobacillus pleuropneumoniae biotype 2 isolated from haemorrhagic necrotic pleuropneumonia of swine were examined. For serologic typing, the indirect haemagglutination (IHA) and the double gel-diffusion tests were used. On the basis of their soluble surface antigens, our A. pleuropneumoniae biotype 2 isolates could be assigned to two proposed serotypes. Serotype 1 comprised 11 strains and serotype 2 comprised 10 strains. All strains contained two surface antigen components. In the strains belonging to serotype 1, one of the antigens was identical with the serotype-specific antigen of Pasteurella haemolytica T4. Both antigens of serotype 2 strains proved to be type-specific. Four strains received from Switzerland, including the holotype strain of A. pleuropneumoniae biotype 2, and three strains isolated from swine in the G.D.R. belonged to serotype 2. Both the double gel diffusion and the IHA tests detected a 2-way cross-reaction between biotype 1, serotype 2 and biotype 2, serotype 2 strains of A. pleuropneumoniae, which could be eliminated using cross-absorbed sera.     

紫花苜蓿根瘤菌分子分型和生物型划分研究

根据表型和共生效应,对种内根瘤菌划分生物型,为苜蓿与根瘤菌高效共生育种提供理论依据。以分离自甘肃省3个栽培区域5个苜蓿品种植株不同部位的根瘤菌株为材料,进行16SrRNA测序、多位点序列分型(Multilocus Sequence Typing,MLST)、表型数值分类和共生效应测定。结果表明,78株初筛菌经16SrRNA和MLST分析有20株属于Rhizobium radiobacter;表型特征数值分类将其聚为7个群。接种5个苜蓿品种,选择对共生效率贡献率最大的地上干重进行多重比较。当接种处理地上干重显著高于未接种处理CK时标记共生效应为A,与CK差异不显著时标记为B,显著低于CK时标记为C。以苜蓿品种为甘农3号、甘农9号、陇中、清水和WL168HQ的顺序,将各菌株共生效应结合,形成6种共生模式。结合表型和共生模式,20株R.radiobacter被划分为14种生物型,WL168HQ、甘农3号和陇中苜蓿品种内生物型多样性丰富,甘农9号和清水苜蓿品种内生物型单一。综上所述,根据表型特征和共生模型可以进行种内根瘤菌株的生物型划分,苜蓿品种内根瘤菌生物型多样性丰富。     

Analysis of occurrence of virulence genes among Yersinia enterocolitica isolates belonging to different biotypes and serotypes

The 150 Y enterocolitica strains isolated from humans and from pigs belonged to biotypes 4 (68.7%), 1A (18.7%) and 2 (4%), or were biochemically untypeable (8.6%). Biotype 4 was comprised of Y. enterocolitica strains representing serotype O:3, within biotype 1A the strains either belonged to serotypes O:5 and O:6 or were untypeable, and biotype 2 was represented by the strains of serotype O:9. The strains which were biochemically untypeable belonged to serotypes O:5, O:6 and O:3. Among the strains tested there also were those of an unidentified biotype and serotype. Nearly all the strains of biotype 1A represented genotype ystB+myfA+, and few belonged to genotype ystB+. The presence of the ystB gene in the strains of biotype 1A and only occasional occurrence of the gene in the other biotypes makes ystB a distinguishing marker of biotype 1A. The strains of genotype ystA+ail+myfA+yadA+ predominated in biotype 4 (serotype O:3). The strains of biotype 2 (serotype O:9) represented genotype ystA+ail+myfA+, and the plasmid yadA gene was detected in some of them. Within the group of biochemically untypeable strains ystB- and myfA-specific PCR products were mainly obtained. The genotypes determined for the tested biotypes and serotypes of Y. enterocolitica, based upon the selected genes of virulence, can be applied as distinguishing markers and indicators of the potential virulence of Y. enterocolitica strains, excluding bioserotyping.     

New findings on the biotyping of Staphylococcus aureus isolated during milk processing]

A detailed analysis of biotypes of Staphylococcus aureus, as related to their origin and enterotoxigenicity, was performed, using 432 strains isolated from bulk milk, milking machines, quarter milk samples collected from mastitic cows, and cowherds and milkers. All strains coagulated rabbit blood plasma and produced thermonuclease (Tab. I). Human strains differed from bovine ones mostly in the production of alpha-haemolysin (94%) and fibrinolysin (66%). Biotypes C1 (35%) and C2 (38%) dominated clearly among the strains isolated from quarter milk samples. The findings of 13% of biotype A and 8% of biotype D suggest that other sources of udder infections than mastitic cows were involved. Almost 19% of human strains and two strains isolated from quarter milk samples were identified as the recently defined type G. The production of enterotoxins (Tab. III) of was associated mostly with strains of human origin (69%) and with biotypes G (35%) and A (31%). Three enterotoxigenic strains belonged to the biotype B and one strain was not classifiable.     

Genomic fingerprinting of pigeon Streptococcus gallolyticus strains of different virulence by randomly amplified polymorphic DNA (RAPD) analysis

Randomly amplified polymorphic DNA (RAPD) analysis was performed on 95 pigeon S. gallolyticus strains of different virulence and belonging to different biotypes and different culture supernatant phenotypes as determined by SDS-PAGE. Four distinct RAPD patterns, designated A, B, C and D, were distinguished using primer OPM6 (5'CTGGGCAACT). All 76 strains generating RAPD pattern A or B were designated highly virulent on the basis of their SDS-PAGE pattern. Five of seven strains generating RAPD pattern C and 11 of 12 strains generating RAPD pattern D belonged to the moderately virulent and low virulent culture supernatant phenotype groups, respectively. Only one RAPD group C strain belonged to a highly virulent culture supernatant phenotype group. There was a correlation between biotype and RAPD patterns. These findings indicate that there is a high correlation between RAPD pattern and virulence for pigeons. Therefore, RAPD typing seems a rapid, reliable method to distinguish pigeon S. gallolyticus strains of high, moderate and low virulence.     

Modern scheme for the diagnosis of staphylococci

A simplified scheme for the subdivision of coagulase-positive staphylococci and another simplified scheme for the diagnostics of coagulase-negative species were worked out. On the basis of the production of staphylokinase, coagulation of human and bovine plasma, acetoin production from glucose, and growth on agar with crystal violet, it is possible to identify S. aureus with its biovars A, B, C1, C2, D, as well as S. intermedius. The coagulase-negative species can be diagnosed according to their sensitivity to novobiocin, nitrate reduction, fermentation of maltose, sucrose, salicin, xylose, trehalose, mannitol and mannose, and haemolytic activity. The proposed diagnostic schemes were verified with success on the collection strains and on the 1305 staphylococci strains isolated largely from the bovine mammary gland, from dogs, man and domestic fowl. In S. aureus strains a close correlation was demonstrated between their biotype characteristics and the host species. A similar correlation was determined for S. intermedius. As to the coagulase-negative species, S. epidermidis, S. hominis and S. haemolyticus were diagnosed most frequently. Both schemes represent a reliable, prompt and technically simple method of the diagnostics of the Staphylococcus microorganisms.     

Probable transmission between animals of a plasmid encoding aminoglycoside 3-N-acetyltransferase IV and dihydrofolate reductase I

Ten aminoglycoside-resistant Escherichia coli isolated from the faeces of healthy or diarrhoeic animals reared in the same herd were studied. These strains were resistant to high levels of apramycin and low levels of gentamicin. They were also resistant to streptomycin, tetracycline, trimethoprim and some to ampicillin, chloramphenicol, kanamycin or nalidixic acid. Two strains, isolated from a calf and a lamb, respectively, belonged to the same biotype. All the transconjugants resistant to gentamicin-apramycin were also resistant to streptomycin, tetracycline and trimethoprim. In all cases, these resistances were encoded by plasmids of 100 kb. Analysis of these plasmids by agarose gel electrophoresis after digestion by EcoRI or BamHI revealed their similarity. Hybridization with a 500-bp HpaI insert of plasmid pFE872 was observed with DNA from field strains and their transconjugants, demonstrating the presence on the 100-kb plasmids of the gene coding for a dihydrofolate reductase I. A single plasmid, designated pIP1831, could be observed in identical or different strains isolated from calves or lambs, suggesting the transmission of strains and plasmids between animals of different species.     

Phage typing coagulase-positive staphylococci from rooks and gulls

Phage typing was performed on 86 strains of Staphylococcus aureus and 25 strains of Staphylococcus intermedius from rooks and gulls with human, bovine, chicken and canine phages. Eighty per cent of the S aureus strains and 64 per cent of the S intermedius strains were typable. The S aureus biotype D strains of rook origin were specifically lysed at routine test dilution (RTD) by chicken phages from groups I or I + IV, by human phages belonging to groups I and M, and partly by canine phage 58. The other rook and gull S aureus strains did not show characteristic phage patterns. The S intermedius strains isolated from both species of birds could be typed only with canine phages and this correlated with their classification into biotypes. All the biotype 1 strains tested but only two of 12 biotype 2 strains were lysed with canine phages at RTD.     

Analysis of the presence of ail, ystA and ystB genes in Yersinia enterocolitica strains isolated from aborting sows and aborted fetuses

Forty-five Yersinia enterocolitica strains isolated from aborted fetuses and placentas and from vaginal and rectal swabs of aborting sows were subjected to serotyping, biochemical typing and polymerase chain reaction multiplex analyses to detect the presence of the ail, yst A and ystB genes. The isolates were recovered from the internal organs (tonsil, lung, liver, spleen, kidney, mesentheric lymph nodes, small intestine and rectal intestine) of 18 (18.6%) of 97 aborted fetuses examined, two (8%) of 25 aborted placentas and 27 (15.8%) of 172 examined aborting sows. Serotyping of Y. enterocolitica revealed that only six (13.3%) of the examined isolates belonged to serotype O:3, with a considerable number of isolates (31.1%) having serotype O:5, while biochemical studies showed that as many as 40 of the 45 strains belonged to biotype 1A. As expected, the Y. enterocolitica strains of bioserotype 4/O:3 contained ail and ystA genes, while strains of biotype 1A contained only the ystB gene.     

Molecular discrimination of Campylobacter coli serogroup 20 biotype I (Lior) strains.

Plasmid, protein and restriction endonuclease analysis (REA) profiles and multilocus enzyme electrophoresis were used to effect a molecular discrimination of twenty-seven Campylobacter coli serogroup 20, biotype 1 (Lior) strains. These strains were not outbreak-associated but were isolated from a number of different countries and different animal and environmental sources. Each of the techniques was able to discriminate, to various degrees, between the serogroup 20, biotype 1 strains. The choice of a particular technique depends to a large extent on the level of discrimination desired, the previous experiences of the investigator and on the laboratory facilities at hand. REA profiles demonstrated the greatest degree of discrimination between these strains. Plasmid and protein profiles could discriminate reasonably well. Multilocus enzyme electrophoresis (allozyme typing) and protein profiles may prove effective in subgrouping serogroup 20, biotype 1 strains.     

Serotypes and electrophoretic protein profiles of Pasteurella haemolytica isolated from pneumonic ovine lungs.

Serotypes and SDS-PAGE protein profiles of P. haemolytica isolated from pneumonic ovine lungs were investigated. Of 268 P. haemolytica isolates, 232 (86.6%) were serotypable. A total of 12 serotypes were recognized in 20 different geographic origins of central Turkey. The most common serotype was A2, followed by A7, A1 and T4. Serotypes A13, A14, A16 and T15 could not be detected. In SDS-PAGE, marked differences between major bands of biotype A and T strains were found. In numerical analysis of protein profiles, biotype A and T strains were separated at 58% similarity level. Biotype A isolates produced a cluster at 80% similarity level, and biotype T isolates at 92% similarity level. No single cut off level was able to discriminate between each serotype studied and isolates could not be clustered on the basis of their geographic origins.     

Bacterial Identity and Characteristics in Healthy and Unhealthy Respiratory Tracts of Sheep and Calves

Barbour, E.K., Nabbut, N.H., Hamadeh, S.K. and Al-Nakhli, H.M., 1997. Bacterial identity and characteristics in healthy and unhealthy respiratory tracts of sheep and calves. Veterinary Research Communications, 21 (6), 421-430The aim of this study was to compare different bacteriological aspects of the respiratory systems of healthy (H) versus unhealthy (UH) animals with respiratory signs. The prevalence of different bacterial species was determined in the upper and lower respiratory tract of H and UH Najdi sheep, Somali sheep and Holstein calves. The characteristics of Pasteurella spp. isolates, and the biotype of Pasteurella haemolytica were identified in H and UH animals. Eighteen out of 28 (64.3%) of the identified bacterial species in the upper respiratory tract were more prevalent in the nasal cavities of UH Najdi and Somali sheep and Holstein calves with respiratory signs than in apparently healthy animals; four of the most prevalent bacteria in the upper respiratory system of UH sheep were Moraxella spp., Pseudomonas pseudomallei, Erysipelothrix spp., and Pasteurella multocida, while three of the most prevalent bacteria in UH calves were Pasturella haemolytica, Actinomyces spp., and Pseudomonas aeruginosa. The prevalence of six different bacterial species was greater in the lungs of UH animals, namely Actinomyces pyogenes, Erysipelothrix spp., P. haemolytica, Pasteurella ureae, Staphylococcus aureus, and Staphylococcus epidermidis, which could be risk factors in the complexity of the prevalent respiratory diseases of the animals surveyed.Of the biochemical, cytological and colonial characteristics studied in the identified P. haemolytica and P. multocida, two characters were significantly different (p < 0.05) in organisms isolated from UH as compared to those from H animals. These were the higher loss of haemolytic power by the strains of P. haemolytica and the decreased fermentation of trehalose by all the strains of P. multocida recovered from healthy animals.The only biotype of P. haemolytica isolated from H animals was biotype A, while both biotypes A (88.0% of the isolates) and T (12.0% of the isolates) were recovered from UH animals.     

Physiological properties and classification of strains of Treponema sp. isolated from pigs in poland

Fifty-one treponemas were isolated from pigs. Twenty-three isolates with typical morphology and growth characteristic were beta hemolytic, enteropathogenic, produced indole and with exception of three strains did not ferment fructose. These strains were classified as typical T. hyodysenteriae and were usually isolated from pigs with symptoms of mucohemorrhagic diarrhoea. The seventeen other isolates were weakly beta hemolytic after 48 h incubation, enteropathogenic, 12 out of 17 produced indole, 10 out 17 fermented fructose. These strains were usually isolated from pigs with symptoms of gray-green diarrhoea and classified as T. hyodysenteriae 2 biotype or intermediate type. They may be compared with Treponema sp. isolated by Taylor et al. Eleven non enteropathogenic strains showed typical characteristic for T. innocens. Gas chromatography analysis of the fatty acids production from glucose, showed that all isolated treponemas produced acetate and butyrate. Typical T. hyodysenteriae produced additionally propionate. Strains of T. hyodysenteriae biotype 2 produced propionate or isobutyrate as well.     

Biochemical properties and differentiation of coagulase-positive staphylococci from rooks and gulls

Coagulase-positive staphylococci were found in the throats of 46 rooks (69 per cent) and 47 gulls (21 per cent) out of totals of 67 and 229 birds, respectively. Of 111 strains isolated from throat swabs 86 (77.5 per cent) were classified as Staphylococcus aureus and 25 strains (22.5 per cent) as Staphylococcus intermedius. Of the S aureus strains 82 per cent from rooks and 50 per cent from gulls were biotyped. Most of them were identified as biotypes D and B, only a few as biotype A, and none as biotype C. Moreover, among the 24 S intermedius strains (96 per cent) biotypes 1 and 2 could be differentiated according to the type of growth on crystal violet agar and their ability to produce acetoin and acid from maltose, mannitol and trehalose.     

Serological characterization of Actinobacillus pleuropneumoniae biotype 2 strains isolated from pigs in two Danish herds

Eight Actinobacillus pleuropneumoniae biotype 2 strains were isolated in pure culture from lungs of pigs originating from two Danish herds with growing and finishing pigs. The antigenic properties were studied by indirect haemagglutination (IHA) and immunodiffusion (ID) tests using soluble surface antigens and by enzyme-linked immunosorbent assays (ELISA) using capsular enriched fractions and LPS. In all tests the strains proved antigenically homogeneous and serologically distinct from the known biotype 1 and 2 serotypes. Thus, the strains represent a new serotype which is provisionally proposed as biotype 2 serotype 14.     

Actinobacillus suis-like organisms and evidence of hemolytic strains of Actinobacillus lignieresii in horses

Thirty-seven local isolates of Actinobacillus suis-like organisms from diseased and clinically normal horses and 1 llama were compared with reference strains of A suis, A lignieresii, A equuli, A capsulatus, A hominis, A (Pasteurella) ureae, and equine A suis-like organisms (ASLO) previously described in literature. Comparison was by cultural characteristics, carbohydrate fermentation, enzyme profiles, and whole-cell protein polyacrylamide gel electrophoresis. Carbohydrate fermentation, determined by API-CH gallery, divided 36 equine ASLO isolates into 6 API-CH biotypes. The llama isolate was an additional distinct biotype. The biochemical comparisons between A suis and ASLO did not reveal remarkable and consistent differences. Enzyme analysis revealed 5 API-ZYM biotypes, one of which included the same strains as one of the API-CH biotypes and consisted in both instances of 4 esculin-negative ASLO cultures and the reference strain of A lignieresii. We conclude that the 4 strains were hemolytic variants of A lignieresii. Protein electrophoresis disclosed 15 banding patterns, 10 of which represented equine ASLO strains. The reference strains of A suis shared the pattern predominant among equine ASLO. Four of the remaining reference strains of Actinobacillus species each had a unique profile, whereas the type strain of A capsulatus and the llama isolate had similar profiles. The groupings of cultures resulting from the different testing methods had little relation to each other and to the anatomic source of the strains except the strains comprising API-CH biotype II, which originated in the equine respiratory tract, and the A lignieressi cluster.