Impact of sawdust and wood shavings in bedding on pig tuberculous lesions in lymph nodes, and IS1245 RFLP analysis of Mycobacterium avium subsp. hominissuis of serotypes 6 and 8 isolated from pigs and environment

Among 25,027 slaughter pigs raised in two farms, tuberculous lesions were detected in the lymph nodes of 898 (3.6%) of them. Tuberculous lesions were most commonly found in the mesenteric (601; 2.4%) and head (451; 1.8%) lymph nodes. Mycobacteria were isolated from 49 of 120 randomly selected mesenteric, head and bronchial lymph nodes with diagnosed tuberculosis originating from both farms. Forty six Mycobacterium avium subsp. hominissuis, one M. chelonae and two M. fortuitum isolates were found in the lymph nodes of pigs. No statistically significant difference was detected between farms A and B for isolation rates of mycobacteria from the lymph nodes of pigs and their species composition. To investigate the source of the pigs' infections, culture examinations of 117 samples from the external environment were performed. Mycobacteria were isolated from 25 samples from the external environment (21.4%). Mycobacterial isolates were also detected in eleven (91.7%) and two (16.7%) of 12 used sawdust and 12 of non-used (fresh) sawdust samples, respectively. None of 12 wood shavings was culture-positive. Twelve of 13 sawdust isolates were classified as M. a. hominissuis of serotypes 6 and 8 and genotype IS901- and IS1245+; the remaining isolate was classified as species M. fortuitum. Other conditionally pathogenic mycobacteria were only isolated from 12 of the remaining 81 samples from the external environment (excluding bedding). A total of eight isolates (two pig and six sawdust samples originating from farms A and B) were examined by IS1245 restriction fragment length polymorphism (IS1245 RFLP) analysis. These isolates produced five distinct IS1245 RFLP types with more than 20 bands. Based on identical IS1245 RFLP types of one pig isolate and two isolates of used sawdust from farm A, we have concluded that contaminated sawdust was the source of mycobacterial infection for pigs in our study.     

High genetic relatedness among Mycobacterium avium strains isolated from pigs and humans revealed by comparative IS1245 RFLP analysis

Members of the Mycobacterium avium complex cause pig mycobacteriosis and opportunistic human infections. Infections due to environmental mycobacteria are increasing in both industrial and developing countries. Mycobacterium-infected pig carcasses can pass for human consumption due to the poor specificity of meat control by visual detection at the slaughter houses. The genetic relatedness of porcine and human MAC isolates in Finland has been unknown. M. avium isolates isolated from pig organs (n=16) and clinical samples (n=13) were compared by IS1245 RFLP analysis to evaluate the similarity of the isolates obtained from human and porcine samples. Nearly identical multicopy M. avium subsp. hominissuis IS1245 RFLP fingerprints were obtained for isolates of porcine and human origin. IS1245 RFLP patterns of 38% of the porcine and human M. a. hominissuis isolates were >90% similar. The RFLP patterns of two porcine and two human isolates showed >95% similarity. The high similarity of the IS1245 RFLP patterns of the human and porcine M. a. hominissuis isolates indicates close genetic relatedness, suggesting that M. a. hominissuis is transmitted between pigs and humans, or that pigs and humans share common environmental sources of infection. Porcine and human isolates with RFLP patterns differing by only one or two bands were found, which shows that the same M. a. hominissuis strains may infect both humans and pigs.     

RAPD and VNTR analyses demonstrate genotypic heterogeneity of Mycoplasma hyopneumoniae isolates from pigs housed in a region with high pig density

Since differences in the virulence of Mycoplasma (M.) hyopneumoniae strains have been described, the isolation of field strains followed by genotypic and phenotypic characterisation has become a major goal in epidemiological studies. The aim of this study was to compare various M. hyopneumoniae isolates from different pig herds and numerous pigs within the same herd. Therefore, pigs of 109 herds located in North-Western Germany were sampled either on-farm or during necropsies. Overall, 52 isolates of M. hyopneumoniae were recovered from 45 pigs originating from 21 herds. The identity of cultures was confirmed by PCR targeting the 16S-23S intergenic spacer region. Typing of isolates was achieved by random amplified polymorphic DNA (RAPD) analysis and multi-locus analysis of variable number of tandem repeats (VNTR) and demonstrated a high degree of heterogeneity of M. hyopneumoniae isolates. Differences among isolates recovered from animals of the same herd or even from the same pig revealed a grouping into different genotypic clusters. This outcome was observed with both methods. It was concluded that more than one strain of M. hyopneumoniae might be present in a pig herd and even in a single pig, suggesting high genetic heterogeneity between isolates of the same epidemiological source. These factors should be considered when applying nucleic amplification techniques for characterising M. hyopneumoniae strains to specify the epidemiology of infection and to evaluate virulence factors triggering the corresponding disease.     

The presence of methicillin-resistant Staphylococcus aureus on large pig breeding farms in Croatia

Methicillin-resistant Staphylococcus aureus (MRSA) have emerged worldwide and have become resistant to a variety of antibiotics. MRSA colonisation in pigs was first reported from the Netherlands in 2005, where pigs were implicated as a source of human MRSA infections (Voss et al., 2005). This paper presents the first report on the presence of MRSA on large pig breeding farms in Croatia, together with the determination of the mecA gene, the results of spa typing and susceptibility to commonly used antimicrobials. Dust samples (7-11 per farm) were collected from eight large pig farms in Croatia. Of the total 68 swabs, the mecA gene was detected in 24 isolates growing on the MRSA agar. All isolates were resistant to oxacillin, tetracycline and streptomycin, and susceptible only to vancomycin, while 92% of the strains were susceptible to ciprofloxacin. Genotyping of the MRSA strains was performed by spa typing, and revealed t011 (n = 17), t034 (n = 5) and t1451 (n = 2). The results presented here predict that MRSA is present on a large number of pig farms in Croatia.     

Epidemiological studies of Brachyspira pilosicoli in two Australian piggeries

The epidemiology of infection with the intestinal spirochaete Brachyspira pilosicoli within pig herds is incompletely understood. To investigate this further, cross-sectional and cohort studies were undertaken on two piggeries. Faeces were subjected to selective culture, and DNA was extracted from growth on the primary media and amplified by polymerase chain reaction (PCR). On one farm, samples from other animal species and the environment were also examined. Isolates were subjected to multilocus enzyme electrophoresis (MLEE) and pulsed field gel electrophoresis (PFGE). The prevalence on farm A (>2000 sows) was 2.4% (95% confidence interval (CI): 0.3, 4.4%). Infection was largely confined to grower/finisher pigs. The six isolates of B. pilosicoli recovered belonged to a single MLEE electrophoretic type (ET) and a single PFGE type. On piggery B, an 80-sow unit located on a research farm, the prevalence amongst growers and finishers was 12.2% (95% CI: 4.7, 19.6%). There was also evidence that weaners were being infected. Ten isolates obtained were genetically heterogeneous, being divided into six ETs and seven PFGE types. One of four isolates in one ET had an identical PFGE type to those on piggery A, and may have been introduced to piggery B in stock from piggery A. On farm B, B. pilosicoli was also detected by PCR in chickens, effluent pond water and wild ducks on the pond. An isolate from the pond belonged to the same ET as one from a pig, whereas the duck isolates were distinct. This study demonstrates the complex epidemiology of B. pilosicoli infections in piggeries.     

Genetic typing of Malassezia pachydermatis from different domestic animals

In the present study, random amplification of polymorphic DNA, which detects DNA polymorphism in fungal genomic DNA, was applied for genetic typing of Malassezia pachydermatis isolates. Fifty-five isolates from different domestic animals and body sites and the neotype strain CBS 1879 were characterized. Primers M13 and OPT-20 were used to analyse their genetic relatedness and similarity. This technique allowed us to distinguish four different genetic types. The predominant genetic type was observed in isolates recovered from different anatomical locations in all animals. It was the only genetic type found in cats, horse, goat and pig. The other three genetic types were observed only in isolates from external ear canals of dogs. Types II and IV were only recovered from external otitic ears and type III from healthy ears. An animal was colonised by more than one type of M. pachydermatis and different genetic types were detected in the same body site. Some genetic types were only isolated from diseased skin.     

Molecular heterogeneity in clinical isolates of Malassezia pachydermatis from dogs

Molecular investigation of 16 strains, conventionally identified to be Malassezia pachydermatis, isolated from dogs in Japan was carried out by random amplification of polymorphic DNA (RAPD) and chitin synthase 2 (CHS2) gene sequence analyses. The RAPD band patterns of 13 clinical isolates were identical to that of standard strain of M. pachydermatis (CBS-1879). The other three clinical isolates were different from the standard strain of M. pachydermatis in RAPD patterns, and two of the three isolates were identical. About 620 bp genomic DNA fragments of the CHS2 gene were amplified from the same 16 clinical isolates of M. pachydermatis by polymerase chain reaction (PCR) and sequenced. The phylogenetic analysis of the nucleotide sequences of CHS2 gene fragments of the 16 clinical isolates revealed that the 13 strains were genetically very close to the standard strain of M. pachydermatis and the other two isolates were genetically close to the standard strain of M. furfur rather than M. pachydermatis. The remaining one isolate was phylogenetically distinct from all the seven Malassezia species reported so far.     

Comparative macrorestriction and RFLP analysis of Mycobacterium avium subsp. avium and Mycobacterium avium subsp. hominissuis isolates from man, pig, and cattle

In Germany, tuberculous lesions in slaughtered pigs due to infection with members of the Mycobacterium avium complex are increasingly reported. Contaminated food originating from pig or other livestock is discussed as potential source of human infection. M. avium isolates from man (n=45), pig (n=29), and cattle (n=13) were characterised by restriction fragment length polymorphism (RFLP) with respect to insertion sequences IS1245 and IS901 as well as by XbaI-based pulsed-field gel electrophoresis (PFGE) and the results were compared by computer cluster correlation analysis, to determine potential sources of infection in man. By PCR, 55% of animal isolates was identified as M. avium subsp. avium, and 45% as M. a. hominissuis. All human isolates belonged to M. a. hominissuis. IS1245-RFLP and PFGE resulted in two distinct main groupings reflecting the two subspecies, and dividing the isolates into several subgroups. Animal isolates of M. a. hominissuis were widely distributed within the subgroups of human isolates. M. a. avium isolates, further discriminated by IS901-RFLP, formed host-associated subgroups for animals. Comparison of RFLP patterns with those of PFGE resulted in different subgroups as well as different pairs of isolates with high similarities. Only two isolates exhibited identical patterns by both methods. In general, results of both methods support the possibility that M. a. hominissuis isolates from livestock represent a source of infection for man, probably by common environmental reservoirs. There was no evidence of human infections caused by M. a. avium in Germany.     

Carriage of Malassezia spp. yeasts in Cornish Rex, Devon Rex and Domestic short-haired cats: a cross-sectional survey

Carriage of Malassezia spp. yeasts in healthy Cornish Rex cats (CRC) was compared with that in Devon Rex (DRC) and Domestic short-haired (DSH) cats. Samples obtained from the left external ear canal, anus and claw fold of digit III of the left fore foot by swabbing, and the axilla and groin using contact plates, were incubated for yeasts on modified Dixon's agar at 32 degrees C for 7 days. Malassezia species were isolated from 90% of the DRC, but from only 39% of the CRC and 50% of the DSH cats. M. pachydermatis accounted for 121 of 141 Malassezia spp. isolates. Five CRC were colonized by M. pachydermatis alone, one CRC yielded only M. nana, and one cat yielded only M. slooffiae, whereas five CRC were colonized by both M. pachydermatis and M. nana and another yielded M. pachydermatis, M. slooffiae and M. nana. M. nana was primarily isolated from the ear canal, whereas M. slooffiae was most often isolated from the claw. Both the frequencies of isolation and the population sizes of M. pachydermatis at all sites sampled in the CRC were comparable to those of 10 healthy DSH cats. Populations of M. pachydermatis in the left axilla and left and right groin in the CRC were significantly lower when compared with counts in a group of 21 healthy DRC, a breed with very similar coat characteristics but prone to seborrheic dermatitis caused by M. pachydermatis.     

Isolation and characterization of a new porcine mycoplasma

In a study on the distribution of Mycoplasma sui- (hyo-) pneumoniae (M. suip.) among Danish swine it was found that most isolates possessing the characteristic colonial morphology of M. suip. would be inhibited significantly in the growth inhibition (g.i.) and metabolic inhibition (m.i.) tests by antiserum for a type strain* of this species. However, a few isolates were found to be completely unaffected by this antiserum. Five such strains have been recovered, viz. 4 from cases of catarrhal pneumonia in bacon pigs, 1 from the nasal cavity of a 40-kg pig. The pigs in question originated from 5 different herds. The recovery of 1 of the strains has been reported (Friis 1971b).     

Production of exfoliative toxin by isolates of Staphylococcus hyicus from different countries

A total of 218 isolates of Staphylococcus hyicus from pigs in eight countries (Belgium, Croatia, Germany, Japan, Korea, Slovenia, the uk and the usa) and 44 isolates from other animals in Belgium, India, Japan and the usa were examined for the genes encoding the exfoliative toxins ExhA, ExhB, ExhC and ExhD by multiplex pcr. The expression of the toxins was confirmed by immunoblot analysis, using monoclonal or polyclonal antibodies specific for each of the toxins. The porcine isolates were from pigs with exudative epidermitis, pigs with other lesions and from healthy pigs, and one or more of the toxins could be found among the isolates from the pigs in all the countries. Toxigenic strains of S hyicus were isolated from both healthy and diseased pigs, but the chance of isolating toxigenic strains from pigs with exudative epidermitis was greater than from pigs with other lesions or healthy pigs. Of the 44 isolates from other animal species, only one isolate, from a hare from Belgium, produced ExhB, and one isolate, from a cow with mastitis from Japan, produced ExhA.     

Antibiotic resistance among indicator bacteria isolated from healthy pigs in New Zealand

AIM: To determine the resistance to antibiotics among the indictor bacteria, Escherichia coli and Enterococcus spp, isolated from the faeces of healthy pigs on three conventional pig farms and one organic farm in the North Island of New Zealand. METHODS: Faecal samples, collected at intervals between March and October 2001, were plated onto MacConkey agar and Slanetz-Bartley agar and examined after 1-3 days incubation for colonies resembling E. coli and Enterococcus spp, respectively. Typical colonies were subcultured for further identification and storage. The isolates were tested for antibiotic resistance, using disc diffusion, to ampicillin, gentamicin, streptomycin, and tetracycline. Escherichia coli isolates were also tested for resistance to ciprofloxacin, cotrimoxazole and neomycin. Enterococcus spp isolates were also tested for resistance to vancomycin, erythromycin and virginiamycin. RESULTS: A total of 296 E. coli and 273 Enterococcus spp isolates were obtained from the three conventional farms, and 79 E. coli and 80 Enterococcus spp isolates were obtained from the organic farm. All the E. coli isolates from both the conventional and organic pig farms were susceptible to ciprofloxacin, and all the Enterococcus spp isolates were susceptible to ampicillin, gentamicin and vancomycin. Isolates of E. coli from conventional pig farms were resistant to gentamicin (0.7%), neomycin (0.7%), ampicillin (2.7%), cotrimoxazole (11%), streptomycin (25%) and tetracycline (60%). Enterococcus spp isolates from the same farms were resistant to erythromycin (68%), tetracycline (66%), streptomycin (54%) and virginiamycin (49%). By contrast, for the organic pig farm 相似文献   

Phenotypic characteristics and virulence genotypes of Trueperella (Arcanobacterium) pyogenes strains isolated from European bison (Bison bonasus)

In a breeding and fattening pig farm an increasing number of cases of abortion and generalized mycobacteriosis at slaughter occurred. Pathological findings compatible with mycobacteriosis, acid-fast organisms in tissues, and isolation of mycobacteria from tissue samples including fetuses, lungs and reproductive organs from sows, genital swabs, mesenteric lymph nodes, and from a sperm sample revealed the cause of the disease. Bacterial cultures were identified as Mycobacterium avium subsp. hominissuis using IS901-/IS1245-specific PCR. Genotyping of selected isolates from animals as well as from their environment by MIRU-VNTR analysis showed that the herd was infected with one single outbreak strain. The same genotype was also isolated from pigs of two other farms which showed comparable symptoms and were in direct contact with the index farm as well as from their environment. Immunological host responses detected by tuberculin skin test and ELISA gave positive results at herd level only. Despite the detection of other potential pathogens mycobacteria were regarded as the causative agent of the reproductive disorders. To our knowledge this is the first report of an epidemic mycobacterial infection in a pig holding associated with reproductive disorders, which could be attributed to one single virulent strain, and the first report of detection of M. avium subsp. hominissuis in pig sperm.     

Pathogenicity of Campylobacter jejuni and Campylobacter coli strains in the pregnant guinea pig model

Pathogenicity of 17 Campylobacter isolates for pregnant guinea pigs was investigated. Of 14 isolates, 12 (86%) produced rates of abortion ranging from 13% to 87%. Two isolates did not produce abortion. Reference strains of C fetus subsp venerealis produced abortion in 60% to 87% and C fetus subsp fetus produced abortion in 60% of the guinea pigs. Inoculated organisms were recovered from uterus, blood, liver, kidney, spleen, and gallbladder of the guinea pigs at rates as high as 83% for 2 ovine isolates and as low as 13% for 2 bovine and 1 human isolates. Most isolations were from the uterus. Two avian isolates were not recovered. Within the C jejuni and C coli group, the ovine and the human isolates appear to be more pathogenic. Swine, bovine, and avian isolates were less pathogenic. Seemingly, the pregnant guinea pig was a suitable and practical model for evaluating the pathogenicity of Campylobacter organisms, regardless of their host of origin.     

Genetic typing of recent classical swine fever virus isolates from Croatia

During a period of 5 years (1997-2001) several outbreaks of classical swine fever (CSF) were recorded in Croatia. For genetic typing, fragments of 150 nucleotides within the 5'-non-translated region (5'-NTR) and 190 nucleotides within the E2 glycoprotein coding gene of nine field isolates that were derived from domestic pigs and wild boars were used. For better epizootiological understanding, isolates from other European countries were included in the study. The results show that the isolates belong to subgroups 2.1 and 2.3 of CSF virus. Isolates from subgroup 2.1 were collected from domestic pigs during sporadic outbreaks in June 1997 and are genetically closely related. A genomic similarity between these isolates and CSF virus isolates from pigs in other European countries from the same year could also be confirmed. In contrast, the isolate from October 1997 was found to be a member of subgroup 2.3, and is closely related to European CSF virus isolates from outbreaks in the last decade in Western and Central European countries. These results show that two different sources of CSF virus caused outbreaks in Croatia during the same year. Furthermore, a close relationship was found between an isolate from a domestic pig in 1999 and isolates of subgroup 2.3 that originated from Croatian wild boars.     

Polymerase chain reaction-based restriction fragment length polymorphism pattern of porcine reproductive and respiratory syndrome virus directly from lung tissues without virus isolation in Korea.

Polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) analysis was developed for directly typing porcine reproductive and respiratory syndrome virus (PRRSV) from lung specimens without virus isolation. Twenty nine lung specimens collected from postweaning pigs were isolated for PRRSV. When the PCR products from the 29 lung specimens were digested by the restriction enzymes MluI, HincII, SacII and HaeIII, the RFLP patterns from the 29 lung specimens matched with those from the corresponding PRRSV isolates from each pig. The results suggest that the PCR-based RFLP analysis method may be useful to distinguish PRRSV isolates directly from lung specimens without virus isolation.     

Effects of beta-thujaplicin on anti-Malassezia pachydermatis remedy for canine otitis externa

The antifungal activity of beta-thujaplicin was evaluated against 51 Malassezia pachydermatis strains isolated from canine ear canals with or without otitis externa. For comparison, sensitivity tests were performed on M. pachydermatis isolates for nystatin, ketoconazole, and terbinafine HCl, all clinically available antifungal agents. The minimal inhibition concentrations over 50% of the tested isolates (MIC50) were 3.13 microg/ml for beta-thujaplicin and nystatin, 0.016 microg/ml for ketoconazole, and 1.56 microg/ml for terbinafine HCl. The antifungal effect for M. pachydermatis of beta-thujaplicin compared favorably with commercial antifungal agents. None of the 51 M. pachydermatis isolates showed resistance against any of the tested antibiotics investigated in this study. Ten representative isolates of M. pachydermatis were subcultured for 30 generations at concentrations close to the MIC levels of beta-thujaplicin, nystatin, ketoconazole, and terbinafine HCl, and examined to determine whether they had acquired resistance to each drug. As a result, M. pachydermatis was found to achieve resistance more easily for ketoconazole and terbinafine HCl than for beta-thujaplicin or nystatin. The MIC50 of beta-thujaplicin did not change during the course of subculture, and it is thought that the potential development of a resistant strain is low, even with continuous infusion for otitis externa therapy. beta-Thujaplicin is an inexpensive and safe treatment with anti-inflammatory and deodorant effects that can be recommended as an effective remedy for canine otitis externa.     

副猪嗜血杆菌血清型和外膜蛋白P5基因型多样性的研究

副猪嗜血杆菌(Haemophilus parasuis,Hps)的血清型及基因型具有复杂多样性。本研究用间接血凝试验对某一猪场分离的Hps进行血清分型鉴定,并对部分菌株的外膜蛋白P5基因进行克隆测序和进化发育分析。试验结果显示,在21头病死猪不同部位共分离了42株Hps,其中 Hps血清5型17株(40.7%)、血清14型12株(28.5%)、血清4型1株(2.3%)和未定型12株(28.5%)。本试验中有5头猪同时感染2种不同血清型的Hps。21株Hps临床分离株分属5个不同基因序列型(STA～STE),其中STA有12株(12/21)为优势基因型;相同血清型的Hps分离株具有不同的STs型,来自同一头猪的Hps血清型和STs型也不相同。以上结果表明,同一猪群感染的Hps血清型和基因型存在明显的多样性,同一头猪感染Hps的血清型和基因型也存在多样性。本研究为进一步揭示猪群感染Hps的复杂性,研究该病的感染与流行机制提供了有价值的参考。     

Paratuberculosis and avian tuberculosis infections in one red deer farm studied by IS900 and IS901 RFLP analysis

As the attempt to eradicate paratuberculosis in one red deer (Cervus elaphus) farm failed, all 167 red deer of different age groups were slaughtered and examined by culture for mycobacteria, and the farm was closed down. Spleen and hepatic lymph nodes, mediastinal lymph node, ileocecal lymph node, and ileum were collected from each animal and examined (a total of 835 organs). Neither tuberculosis lesions nor pathognomic signs of paratuberculosis were detected. Among all microscopically negative for mycobacteria organs, Mycobacterium avium subsp. paratuberculosis alone was isolated from 165 organs, M. a. avium alone from 41 organs, and both pathogens from four organs. M. a. paratuberculosis alone was detected in 71 red deer, M. a. avium alone in 13 red deer and both pathogens in 18 red deer. Using standardised RFLP methods, three IS900 RFLP types B-C1, B-C16, and B-C32 were identified among 40 M. a. paratuberculosis isolates and four IS901 RFLP types N-B1, N-B3, N-B4, and P-B3 among 17 M. a. avium isolates.     

A study of the prevalence of methicillin-resistant Staphylococcus aureus in pigs and in personnel involved in the pig industry in Ireland

To evaluate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in the pig population in Ireland, nasal swabbing was employed in three abattoirs to screen 440 pigs from 41 geographically distributed farms. One hundred individuals involved in the pig industry were also nasally screened. No MRSA isolates were recovered from the pigs and only two of the humans tested were identified as MRSA carriers. Importantly, MRSA was not obtained from pig producers, veterinarians or abattoir employees, but was isolated from individuals working in the wider pig industry. Multi-locus sequence typing revealed that these isolates belonged to sequence types (ST) ST22 and ST1307; the latter is a previously unreported single locus variant of ST5. Five dust samples from each of the three slaughterhouses were culture-negative for MRSA. These results indicate that porcine colonisation by MRSA, and in particular the animal-related strain MRSA-ST398, was not common in Ireland during the period of study.