Differentiation of Pasteurella multocida isolates from cases of atrophic rhinitis in pigs from Zimbabwe by RAPD and ribotyping

Atrophic rhinitis in pigs is rarely reported in Southern Africa. To determine the relationship between Pasteurella multocida clones from clinical cases of atrophic rhinitis, twenty-one strains were characterised by selected phenotypic and genotypic methods. Biochemical analysis classified 18 strains as P. multocida subspecies multocida, whilst the remainder were grouped into separate unassigned biotypes. Capsular groups A (16/21) and D (l/21) were found among the isolates by PCR. Four ribotype patterns were obtained following HpaII ribotyping, whilst random amplification of polymorphic DNA (RAPD) revealed three main clusters. However, subclusters were also noted for each RAPD cluster. Our results indicate that RAPD offers a better discrimination of strains than ribotyping and that none of the phenotypic characters were directly related to the genotypic clusters.     

一规模化猪场断奶仔猪腹泻大肠杆菌毒力因子的检测

从疑似断奶仔猪腹泻的仔猪中分离、鉴定出15株病原性大肠杆菌。经O血清型鉴定,11株为0131、4株未定型,所有O131血清型菌株呈β溶血。多重PCR检测毒素基因(STa、STb、LT、SLT-2e)和大肠杆菌粘附素单抗(F4、F5、F6、F41、F18)检测菌毛,O131菌株的毒素为STa、STb、SLT-2e,表达F18粘附素,未定型菌株的毒素为STa,共表达F6和F18粘附素。对15株大肠杆菌用16种抗生素进行药敏试验,结果表明:分离株对阿米卡星、痢特灵、新霉素敏感,而对多种抗生素产生了不同程度的耐药性。运用本场大肠杆菌分离株灭活苗免疫猪群,取得良好效果。     

Prevalence of serogroups and virulence factors of Escherichia coli strains isolated from pigs with postweaning diarrhoea in eastern China

This study was undertaken to determine the present distribution of serogroups, hemolytic activity and virulence factors among Escherichia coli strains isolated from pigs with postweaning diarrhoea from eight provinces in eastern China. Two hundred and fifteen E. coli isolates were serogrouped with O-antisera, investigated for hemolytic activity, assessed for F4, F5, F6, F18 and F41 fimbrial antigens by monoclonal antibodies and detected for genes of enterotoxins and shiga-toxin-two-variant (Stx2e) by a multiplex polymerase chain reaction (PCR). Among these E. coli isolates, 140 were determined to be placed in serogroups, 52 were unable to be serogrouped and the rest 23 auto-agglutinated. These isolates distributed in 45 serogroups and 64.3% (90/140) belonged to 12 O serogroups: O8, O9, O11, O20, O32, O91, O93, O101, O107, O115, O116 and O131. Hemolytic activity was detected in 11.6% (25/215) of all isolates. Several uncommon O serogroups were discovered in this study. Agglutination tests showed that 50.2% (108/215) of these isolates were positive for one or more of the five fimbrial antigens. Seventy-two E. coli strains expressed single fimbria and 36 strains expressed two or more fimbriae. Among these 215 E. coli isolates, strains expressing F18, F4, F6, F6 + F18 or F5 + F41 occurred more frequently. PCR analysis showed that 60.5% (130/215) of the isolates only harboured the gene of estI (STI) while 6.0% (13/215) strains possessed the genes of stx2e, estI and estII and 5.6% (12/215) of strains had the genes of estI/estII. Of all these isolates, 107 (49.8%) were negative for the fimbrial antigens examined. The fimbria-negative isolates usually possessed genetic determinant of estI (78, 72.9%).     

Comparison of ITS Profiling,REP‐ and ERIC‐PCR of Salmonella Enteritidis Isolates from Poland

Thirty‐one Salmonella Enteritidis strains isolated from chickens, broilers and hens were analysed by genotypic typing including REP‐PCR, ERIC‐PCR and ITS profiling (PCR‐ribotyping). Analysis of DNA banding patterns generated by REP‐PCR revealed the presence of 22 different genotypes, which were grouped by dendrogram analysis into three distinct lineages (maximum similarity approx. 50%). Each isolate of S. Enteritidis analysed by ERIC‐PCR generated an individual DNA pattern. Again, these isolates could be divided into three distinct genomic groups (maximum similarity approx. 60%) by their ERIC‐PCR fingerprints. REP‐ and ERIC‐PCR were found to be more discriminatory for typing of S. Enteritidis than ITS profiling. Amplification of the 16S‐23S rDNA spacer region gave nine different profiles of DNA, subdivided into two closely related groups by dendrogram analysis. In summary, data obtained by genotyping methods for S. Enteritidis isolates from regions located in the south‐west and the central parts of Poland revealed an enormous heterogeneity among analysed samples, and proved that REP‐ and ERIC‐PCR are highly discriminatory techniques, which can be used, in addition to conventional methods, in epidemiological studies of S. Enteritidis infections.     

Virulence markers and genetic relationships of Shiga toxin-producing Escherichia coli strains from serogroup O111 isolated from cattle

Shiga toxin-producing Escherichia coli (STEC) strains isolated from healthy cattle (O111:NM, seven strains; O111:H8, three strains) in Brazil were studied and compared to previously characterized human strains in regard to their phenotypic and genotypic characteristics to evaluate their pathogenic potential. Most bovine STEC O111 strains were isolated from dairy calves, and strains with genotypes stx1 alone and stx1/stx2 (variant stx2) occurred in different regions. Irrespective of the stx genotype, all strains were positive for eae theta, alpha variants of tir, espA and espB, and for ler, qseA, iha, astA and efa1 genes. Only one strain was negative for EHEC-hlyA and all strains were negative for iha, saa and espP genes and for EAF and bfpA, genetic markers of EPEC. Except for the presence of stx2, bovine strains showed the same profile of putative virulence genes found among the human strains. Similar biochemical behavior was identified among the strains analysed. Two bovine STEC strains produced the localized adherence (LA) phenotype in 6-h tests with Caco-2 (human enterocyte) cells. Intimate attachment (judged by the FAS test) was found in 9 out of 10 bovine strains as it was observed for the human STEC strains. RAPD-PCR analysis showed two distinct RAPD groups among the STEC O111 strains examined. Despite the relative low frequency of STEC O111 strains recovered from cattle no differences in their pathogenic potential were observed compared to some strains isolated from human diarrhea, suggesting that healthy cattle may be a potential source of infection for humans in Brazil.     

Genetic diversity among Escherichia coli O149:K91 strains isolated from pigs with diarrhoea determined by randomly amplified polymorphic DNA analysis.

The genetic relatedness among 72 Escherichia coli strains of serotype O149:K91 isolated from pigs with diarrhoea was investigated by randomly amplified polymorphic DNA (RAPD) analysis. Fimbrial and toxic virulence markers of the isolates were also tested. Amplification with primer 1254 resulted in three different RAPD types whereas primer 1290 generated one RAPD profile only. Based on the RAPD and fimbrial/toxin types the strains were classified into five distinct groups.     

Prevalence of Escherichia coli O157:H7 prophage-like sequences among German Salmonella enterica serotype Typhimurium phage types and their use in detection of phage type DT104 by the polymerase chain reaction

A 1.6kb DNA fragment identified by random amplifiable polymorphic DNA differentiation (RAPD) from a Salmonella enterica serotype Typhimurium phage type DT104 isolate was used to investigate the prevalence of the region in 160 DT104 isolates, 83 other epidemiological important S. Typhimurium phage types and 20 strains selected from 17 other Salmonella serotypes. PCR screening tests using two different primer-sets derived from the RAPD fragment's nucleotide sequence showed that 76% of the 160 DT104 isolates investigated, including subtypes DT104A, DT104B, DT104B low, DT104H and DT104L, reacted positively. High sensitivity was shown for DT104 strains expressing at least the penta-resistance pattern ACSSuT (97% of 104 strains tested). DT104 susceptible strains showed only a sensitivity of 35% (17 strains tested). In contrast, 83% of the 83 strains from the other S. Typhimurium phage types reacted negatively. Strains from five out of the 17 other serotypes showed a positive signal with one primer-set. The other primer-set exhibited only a positive reaction with one S. Dublin isolate. The analysis of a 2415bp extended sequence revealed homologies to genes encoded by Escherichia coli O157:H7 prophages, suggesting that the described region contains genes of a prophage specific for DT104 and related phage types.     

Identification of Escherichia coli O157:H7-strains from pigs with postweaning diarrhoea and amplification of their virulence marker genes by PCR

Escherichia coli isolated from pigs with postweaning diarrhoea were examined by PCR for the presence of the O157 rfb gene responsible for the biosynthesis of E coli O157 lipopolysaccharide. Among the 372 isolates tested, 38 (10.2 per cent) were of the O157 serogroup, but none of these possessed the H7 determinant. Further analysis of the E coli O157 isolates revealed that seven of them had the genes responsible for the production of Shiga toxin 1 and eaeA intimin, four other strains had genes responsible for the production of Shiga toxin 2, and four other strains were positive for the enterohaemolysin gene.     

The use of polymerase chain reaction for determination of virulence factors of Escherichia coli strains isolated from pigs in Poland.

E. coli strains isolated from pigs with postweaning diarrhea or edema disease were tested by phenotypic and genotypic methods for the presence of virulence antigens and genes, respectively. The slide agglutination and ELISA analyses were used for determination of F4, F5, F6, F17, and F41 fimbriae whereas the prevalence of fimbrial fedA and toxin eltI, estI, estII, stx1, stx2 and stx2e genes were recorded by the means of PCR. Only F4 antigen (ac variant) was found in strains of the serogroup O149:K91 isolated from pigs with diarrhea. PCR analyses showed that the fedA gene encoding F18 fimbriae was present in 61.9% of strains isolated from pigs with diarrhea and in 84.2% of strains isolated from pigs with edema disease. The eltI genes encoding heat-labile toxin I (LTI) were present only in 9 out of 21 strains recovered from pigs with diarrhea. Shiga toxin 2 variant (stx2e) genes were found in six isolates from edema disease and also in one strain from diarrhea. The PCR test used in the study was a sensitive and valuable method for determination of virulence factors of E. coli strains.     

Molecular characterisation of Shiga toxin-producing Escherichia coli O157 strains isolated in Poland

Ten Escherichia coli O157 strains isolated from cattle and children in Poland were investigated by the use of molecular biological methods. All strains possessed the intimin and enterohaemolysin genes and harboured the genetic determinants for Stx2 toxin (five isolates), Stx1 toxin (two strains) or both (three isolates). The genetic relatedness of the strains was examined by restriction fragment length polymorphism (RFLP) of chromosomal DNA digested with Xbal and Notl. Nine closely related RFLP patterns were observed. Comparison of bovine and human E coli O157 isolates based on the analysis of Xbal and Notl digested profiles showed that all strains belonged to one genetic cluster. These results indicate that cattle must be considered as a possible source of human E coli O157 infection in Poland.     

Genetic variability of avian Escherichia coli strains evaluated by enterobacterial repetitive intergenic consensus and repetitive extragenic palindromic polymerase chain reaction

In this study, we tested the capability of enterobacterial repetitive intergenic consensus (ERIC) and repetitive extragenic palindromic (REP) polymerase chain reaction (PCR) to detect genetic diversity among Escherichia coli strains isolated from chickens bearing clinical signs of colibacillosis and compared the genotypes so obtained with the O:H serotypes and virulence of those strains. The DNAs from 50 avian E. coli strains and from E. coli ATCC 25922 were used to amplify ERIC and REP sequences. DNA from avian strains produced from 8 to 17 bands by ERIC-PCR and from 6 to 20 bands by REP-PCR; E. coli ATCC produced 11 bands by both methods. ERIC and REP-PCR showed good discriminating power, and the dendograms based on the different patterns revealed extensive genetic diversity among the avian strains. Those strains were allocated into four major clonal clusters, each one with 60% of similarity by ERIC and REP-PCR, and those clusters corresponded to strains with different degrees of pathogenicity. However, 56% of the pathogenic strains (28/50) belonged to two out of three major clonal clusters, and 86% of the nonpathogenic strains tended to group in one cluster and one subgroup. The 32 serotypes detected were distributed in all clusters, and within a serogroup, different DNA fingerprints were observed; however, strains with same serotypes tended to form clusters with similarity coefficients greater than 80%. These results suggest that no specific serotype and genotype is responsible for colibacillosis and that REP and ERIC-PCR are reproducible techniques that can improve the studies needed to clarify the pathways to the pathogenesis of colibacillosis.     

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.     

Serotypes and virulence genes of extraintestinal pathogenic Escherichia coli isolates from diseased pigs in China

Extraintestinal pathogenic Escherichia coli (ExPEC) isolates were detected in 315/3127 (10.1%) diseased pigs from 19 provinces of China; the frequency of isolation increased from 3.1% in 2004 to 14.6% in 2007. All isolates were characterised for O serogroups, haemolysis, phenotypic and genotypic antimicrobial resistance, virulence genes and pathogenicity. The most prevalent serogroups were O161, O8, O11, O138, O101 and O26; 83/315 (26.3%) isolates were haemolytic. Forty percent of isolates in phylogenetic groups B2 and D were highly virulent porcine ExPEC strains. Thirty-three putative extraintestinal virulence factor genes that are normally associated with human and/or avian ExPEC strains were widely present in porcine isolates. These results indicate that ExPEC are prevalent in pigs in China and represent a potential public health threat.     

Characterization of Escherichia coli isolated from adult horses with and without enteritis

In the present study E. coli strains isolated from the faeces of ten horses with diarrhoea and 14 horses without diarrhoea were characterized. All horses were culture negative for Salmonella species. Nine colonies of E. coli from each faecal sample were picked at random and a DNA fingerprint was made by means of a polymerase chain reaction (PCR) using Enterobacterial Repetitive Intergenic Consensus (ERIC) primers. The number of E. coli genotypes did not differ significantly between horses with and without diarrhoea. In addition, all E. coli strains with different DNA fingerprints were tested by PCR for genes encoding the virulence factors K88, F41, F17, CS31a, Sta1, LT1, VT2, CNF, BFP, and intimin. Genes coding for K88, F41, BFP, STa1, VT2, and CS31A were not detected. Genes for CNF were found in strains from one horse with diarrhoea and one horse with normal faeces. Genes for LT1 (n=1) and intimin (n=1) were found only in strains from horses with normal faeces. Genes for F17 fimbriae were found in strains from three horses with diarrhoea (30%) and in none of the strains from healthy horses. In two of these horses, E. coli strains with different DNA polymorphism patterns were F17 positive; however, none of these strains possessed LT1, Sta1, or CNF genes. Haemolytic E. coli strains were only isolated from two horses with diarrhoea and from none of the healthy horses. Nineteen percent of all E. coli strains did not ferment lactose. Eight per cent of these lactose-negative strains were from horses with diarrhoea, whereas 32% were from horses without diarrhoea. In conclusion, virulence factors were present in E. coli isolates from horses with and without diarrhoea, except for F17, which was only found in E. coli isolated from horses with diarrhoea. F17-positive E. coli might have importance as cause of diarrhoea in horses, but further studies are needed.     

Attaching and effacing Escherichia coli isolated from dogs in Brazil: characteristics and serotypic relationship to human enteropathogenic E. coli (EPEC)

Escherichia coli isolates recovered from 182 fecal specimens from dogs up to five months old from the cities of S?o Paulo and Campinas, SP, Brazil, were examined by polymerase chain reaction (PCR) for several virulence factors and properties. The eae gene was found in 23 isolates of E. coli from 22 dogs, 19 of 146 (13%) from dogs with diarrhea and 3 of 36 (8.3%) from dogs with no diarrhea. Two different eae+ isolates were recovered from one dog with diarrhea. Isolates from two dogs with diarrhea harbored the bfpA gene, and none of the isolates possessed genes for enterotoxins, the EAF plasmid or Shiga toxins. PCR showed that, among the 23 isolates, eight were positive for beta intimin, six for gamma, two for, one for alpha, one for kappa, and five showed no amplification with any of the nine pairs of specific intimin primers used. PCR also showed that the LEE (locus of enterocyte effacement) was inserted in selC in four isolates, likely in pheU in seven isolates, and in undetermined sites in twelve isolates. Fifteen isolates adhered to HEp-2 cells and were fluorescence actin staining (FAS) positive. The predominant adherence pattern was the localized adherence-like (LAL) pattern. The eae-positive isolates belonged to a wide diversity of serotypes, including O111:H25, O119:H2 and O142:H6, which are serotypes that are common among human EPEC. These results confirmed the presence of EPEC in dogs (DEPEC) with and without diarrhea. The virulence factors found in these strains were similar to those in human EPEC, leading to the possibility that EPEC may move back and forth among human and canine populations.     

Molecular epidemiology of clinical isolates of Pseudomonas aeruginosa isolated from horses in Ireland

Clinical isolates (n = 63) of Pseudomonas aeruginosa obtained from various sites in 63 horses were compared using ERIC2 RAPD PCR to determine their genetic relatedness. Resulting banding patterns (n = 24 genotypes) showed a high degree of genetic heterogeneity amongst all isolates examined, indicating a relative non-clonal relationship between isolates from these patients, employing this genotyping technique. This study characterised 63 clinical isolates into 24 distinct genotypes, with the largest cluster (genotype E) accounting for 10/63 (15.9%) of the isolates. ERIC2 RAPD PCR proved to be a highly discriminatory molecular typing tool of P. aeruginosa in isolates recovered from horses. With the adoption of several controls to aid reproducibility, this technique may be useful as an alternative to PFGE, particularly in epidemiological investigations of outbreaks where speed may be a significant parameter. This is the first report of clonal heterogeneity amongst P. aeruginosa from horses and demonstrated that ERIC RAPD PCR is a rapid method for the examination of this species in horses, which may be useful in outbreak analysis.     

Rapid detection of virulence-associated genes in avian pathogenic Escherichia coli by multiplex polymerase chain reaction

Based on recently published prevalence data of virulence-associated factors in avian pathogenic Escherichia coli (APEC) and their roles in the pathogenesis of colibacillosis, we developed a multiplex polymerase chain reaction (PCR) as a molecular tool supplementing current diagnostic schemes that mainly rely on serological examination of strains isolated from diseased birds. Multiple isolates of E. coli from clinical cases of colibacillosis known to possess different combinations of eight genes were used as sources of template DNA to develop the multiplex PCR protocol, targeting genes for P-fimbriae (papC), aerobactin (iucD), iron-repressible protein (irp2), temperature-sensitive hemagglutinin (tsh), vacuolating autotransporter toxin (vat), enteroaggregative toxin (astA), increased serum survival protein (iss), and colicin V plasmid operon genes (cva/cvi). In order to verify the usefulness of this diagnostic tool, E. coli strains isolated from fecal samples of clinically healthy chickens were also included in this study, as were uropathogenic (UPEC), necrotoxigenic, and diarrhegenic E. coli strains. The application of the multiplex PCR protocol to 14 E. coli strains isolated from septicemic poultry showed that these strains harbored four to eight of the genes mentioned above. In contrast, those isolates that have been shown to be nonpathogenic for 5-wk-old chickens possessed either none or, at most, three of these genes. We found only one enterohemorrhagic (EHEC), one enteropathogenic (EPEC), and two enterotoxic (ETEC) E. coli strains positive for irp2, and another two ETEC strains positive for astA. As expected, UPEC isolates yielded different combinations of the genes iss, papC, iucD, irp2, and a sequence similar to vat. However, neither the colicin V operon genes cva/cvi nor tsh were amplified in UPEC isolates. The multiplex PCR results were compared with those obtained by DNA-DNA-hybridization analyses to validate the specificity of oligonucleotide primers, and the protocol was concluded to be a useful, sensitive, and rapid assay system to detect avian pathogenic E. coli and differentiate them from nonpathogenic strains and those belonging to other pathotypes.     

Prevalence of ESBLs and PMQR genes in fecal Escherichia coli isolated from the non-human primates in six zoos in China

The aim of this study is to characterize the prevalence of extended-spectrum β-lactamases (ESBLs) and plasmid-mediated quinolone resistance (PMQR) genes in Escherichia coli from captive non-human primates. A total of 206 E. coli isolates were collected from primates in six zoos in China in 2009 and their susceptibility to 10 antimicrobials were tested by broth microdilution. The susceptibility patterns of E. coli strains varied greatly among different zoos reflecting different backgrounds of antimicrobial usage. Both the ESBL-encoding genes and the PMQR genes were detected by PCR. Of the 206 strains, 65 (32%) were confirmed as phenotypic ESBL producers with bla(CTX-M) (27%, bla(CTX-M-15), n=31, bla(CTX-M-3), n=23 and bla(CTX-M-14), n=2) mainly mediating the ESBL phenotype. qnrS1 (18%, n=36) and oqxAB (15%, n=31) were the predominant PMQR genes and the prevalence of PMQR genes was much higher among phenotypic ESBL producers than that among phenotypic non-ESBL producers from any zoo. Notably, the PMQR genes qnrS1 and oqxAB and β-lactamase genes bla(TEM-1) and bla(CTX-M-3) were found together in 23 E. coli isolates in two zoos in Shanghai. PFGE analysis of these 23 isolates demonstrated nearly identical PFGE profiles (similarity matrix >97%) indicating this specific E. coli genotype was prevalent in these two zoos. To the best of our knowledge, this is the first report of these four genes coexisting in an E. coli genotype and the first report of antimicrobial resistance profiles in E. coli isolated from primates in China.     

Serotypes,phage types and virulence genes of shiga-producing Escherichia coli isolated from sheep in Spain

PROBLEM ADDRESSED: Shiga toxin-producing Escherichia coli (STEC), have emerged as food poisoning pathogens which can cause severe diseases in humans. OBJECTIVE: The aim of this study was to determinate the serotypes and virulence genes of STEC strains isolated from sheep in Spain, with the purpose of determining whether sheep represent a potential source of STEC pathogenic for humans. METHODS AND APPROACH: Faecal swabs obtained from 697 healthy lambs on 35 flocks in Spain during the years 2000 and 2001 were examined for STEC using phenotypic (Vero cells) and genotypic (PCR) methods. RESULTS: STEC O157:H7 strains were isolated from seven (1%) animals in six flocks, whereas non-O157 STEC strains were isolated from 246 (35%) lambs in 33 flocks. A total of 253 ovine STEC strains were identified in this study. PCR showed that 110 (43%) strains carried stx(1) genes, 10 (4%) possessed stx(2) genes and 133 (53%) both stx(1) and stx(2). Enterohaemolysin (ehxA) and intimin (eae) virulence genes were detected in 120 (47%) and in 9 (4%) of the STEC strains. STEC strains belonged to 22 O serogroups and 44 O:H serotypes. However, 70% were of one of these six serogroups (O6, O91, O117, O128, O146, O166) and 71% belonged to only nine serotypes (O6:H10, O76:H19, O91:H-, O117:H-, O128:H-, O128:H2, O146:H21, O157:H7, O166:H28). A total of 10 new O:H serotypes not previously reported in STEC strains were found in this study. Seven strains of serotype O157:H7 possessed intimin type gamma1, and two strains of serotype O156:H- had the new intimin zeta. STEC O157:H7 strains were phage types 54 (four strains), 34 (two strains) and 14 (one strain). CONCLUSIONS: This study confirms that healthy sheep are a major reservoir of STEC pathogenic for humans. However, because the eae gene is present only in a very small proportion of ovine non-O157 STEC, most ovine strains may be less pathogenic.     

Molecular characterization of Corynebacterium pseudotuberculosis isolates using ERIC-PCR

Caseous lymphadenitis is an infectious sheep and goats disease caused by Corynebacterium pseudotuberculosis and characterized by abscesses in superficial and visceral lymph nodes. C. pseudotuberculosis strains isolated from these hosts have been shown to be very difficult to type by the existing methods. The aim of this study is evaluating the potential of the Enterobacterial Repetitive Intergenic Consensus (ERIC-PCR) as a tool for molecular typing of C. pseudotuberculosis strains isolated in sheep. One hundred and twenty seven isolates of C. pseudotuberculosis were isolated from lesions suspected to have had caseous lymphadenitis collected from sheep at the slaughterhouse. Animals were from 24 flocks in 13 municipalities of the Minas Gerais State, Brazil. Species identification of the isolates was performed by routine biochemical tests and mPCR. Fingerprint was performed by RAPD using ERIC-1R, ERIC-2 and ERIC-1R+ERIC-2 primers. Seventeen different genotypes were generated by ERIC 1-PCR, 21 genotypes by ERIC 2-PCR and 21 genotypes by ERIC 1+2-PCR. Hunter-Gaston Discrimination Index (HGDI) found for ERIC 1, ERIC 2, ERIC 1+2 PCR were 0.69, 0.87, and 0.84, respectively. For most herds evaluated observed at most three different genotypes among isolates from animals of these property, in all ERIC-PCR assays. However a few flocks observed between four and nine genotypes per flock. The W Kendall value found for correlation among the three techniques of ERIC-PCR was 0.91 (P<5.0 x 10(-6)). The results show that ERIC-PCR has good discriminatory power and advantages over other DNA-based typing methods, making it a useful tool to discriminate C. pseudotuberculosis isolates.