Isolation of a multidrug-resistant Escherichia coli pathotype Stx2:Cnf1:Cnf2:Eae as a potential cause of hemorrhagic diarrhea and secondary septicemia in a dog.

Escherichia coli is a member of the family Enterobacteriaceae and is a commensal in the intestine of many animals as well as humans. Most strains are of low virulence. A dog developed vomiting and hemorrhagic diarrhea after surgery and died despite treatment. Postmortem examination revealed hemorrhagic gastroenteritis and colitis. A multidrug-resistant E. coli, with virulence factors Shiga-toxin-producing gene, stx2, eae gene, and cytotoxic necrotic factors CNF-1 and CNF-2, was isolated from internal organs. E. coli can easily acquire new genes for virulence factors and antimicrobial resistance as demonstrated by this isolate with characteristics of both enterohemorrhagic E. coli and necrotoxigenic E. coli. In addition, the isolate was resistant to all beta-lactam antibiotics tested, as well as to enrofloxacin by a disk diffusion methodology. Broth-based minimum inhibitory concentration analysis confirmed resistance to amoxicillin (>32 µg/mL), enrofloxacin (>32 µg/mL), fosfomycin (>128 µg/mL), and neomycin (>32 µg/mL). The discovery of such strains is a cause for concern given that E. coli can be shared by companion animals and their human owners.

Antimicrobial resistance and mcr-1 gene in Escherichia coli isolated from poultry samples submitted to a bacteriology laboratory in South Africa.

BACKGROUND AND AIM: Antimicrobial resistance (AMR) and recently mobilized colistin resistance (mcr-1) associated colistin resistance among Escherichia coli isolates have been attributed to the overuse of antimicrobials in livestock production. E. coli remains an important pathogen, often associated with mortality and low carcass weight in poultry medicine; therefore, the need to use antimicrobials is common. The study aimed to determine the AMR profile and presence of mcr-1 and mcr-2 genes in avian pathogenic E. coli from poultry samples tested at a bacteriology laboratory for routine diagnosis. This is a first step in understanding the effectiveness of mitigation strategies. MATERIALS AND METHODS: Fifty E. coli strains were assessed for resistance against ten antimicrobial drugs using broth microdilution. All isolates with a colistin minimum inhibitory concentration (MIC) of 2 µg/mL were analyzed for the presence of mcr-1 and mcr-2 genes by employing the polymerase chain reaction. For each isolate, the following farm information was obtained: farm location, type of farm, and on-farm use of colistin. RESULTS: Sixty-eight percent of the strains were resistant to at least one antimicrobial; 44% were multiple drug-resistant (MDR). Most E. coli isolates were resistant to doxycycline (44%), trimethoprim-sulfamethoxazole (38%), ampicillin (32%), and enrofloxacin (32%). None of the E. coli strains was resistant to colistin sulfate (MIC90 of 2 µg/mL). Only one E. coli isolate held the mcr-1 gene; none carried the mcr-2 gene. CONCLUSION: Resistance among E. coli isolates in this study was fairly high. Resistance to commonly used antimicrobials was observed, such as doxycycline, trimethoprim-sulfamethoxazole, and enrofloxacin. Only a single E. coli strain carried the mcr-1 gene, suggesting that mcr-1 and mcr-2 genes are common among isolates in this study. The prevalence of AMR, however, suggests that farmers must implement standard biosecurity measures to reduce E. coli burden, and antimicrobial use to prolong the efficacy life span of some of these drugs.

Draft Genome Sequence of Taylorella equigenitalis Strain ERC_G2224 Isolated from the Semen of a Lipizzaner Stallion in South Africa.

Taylorella equigenitalis is the causative agent of contagious equine metritis (CEM), a sexually transmitted infection of horses. We report here the genome sequence of T. equigenitalis strain ERC_G2224, isolated in 2015 from a semen sample collected in 1996 from a Lipizzaner stallion in South Africa.

Comparison of two culture techniques used to detect environmental contamination with Salmonella enterica in a large-animal hospital.

Salmonellosis is a common healthcare-associated infection in large-animal hospitals, and surveillance for Salmonella is an integral part of comprehensive infection control programmes in populations at risk. The present study compares the effectiveness of two culture techniques for recovery of Salmonella from environmental samples obtained in a large-animal referral veterinary hospital during a Salmonella outbreak. Environmental samples were collected using household cleaning cloths that were incubated overnight in buffered peptone water (BPW). Aliquots of BPW were then processed using two different selective enrichment and culture techniques. In the first technique (TBG-RV-XLT4) samples were incubated at 43 °C in tetrathionate broth and then Rappaport-Vassiliadis broth before plating on XLT4 agar. The second technique (SEL-XLD) involved incubation at 37 °C in selenite broth before plating on XLD agar. Salmonella was recovered from 49.7% (73/147) of samples using the TBG-RV-XLT4 technique, but only 10.2% (15/147) of samples using the SEL-XLD method. Fourteen samples (9.5%) were culture-positive using both methods, and 73 (49.7%) were culture-negative using both techniques. There were discordant results for 60 samples, including 59 that were only culture-positive using the TBG-RV-XLT4 method, and one sample that was only culture-positive using the SEL-XLD method. Salmonella was much more likely to be recovered using the TBG-RV-XLT4 method, and there appeared to be five times more false-negative results using the SEL-XLD technique. Environmental contamination with Salmonella may be underestimated by certain culture techniques, which may impair efforts to control spread in veterinary hospitals.

Molecular characterisation of Mycoplasma species isolated from the genital tract of Dorper sheep in South Africa.

Biochemical and molecular analysis were conducted on 34 strains of Mycoplasma species isolated between 2003 and 2009 from the genital tract of clinically healthy Dorper sheep and sheep with ulcerative vulvitis and balanitis. Earlier publications identified the causative agent as Mycoplasma mycoides mycoides large colony (MmmLC) and Arcanobacterium pyogenes. The aims of the study were to characterise Mycoplasma species isolated from the genital tract of Dorper sheep with polymerase chain reaction assay, cloning and gene sequencing. Basic Local Alignment Search Tool (BLAST) results revealed six predominant Mycoplasma species: Mycoplasma arginini, Mycoplasma bovigenitalium, Arcanobacterium laidlawii, MmmLC, Mycoplasma sp. ovine/caprine serogroup II and M. canadense. Sequencing of the 34 isolates were analysed using phylogenetic methods, and 18 (50%) were identified as M. arginini with 99% - 100% similarity to M. arginini from England and Sweden. Six isolates showed 99% similarity to M. bovigenitalium strains from Turkey and Germany. Two isolates had 99% similarity to an M. sp. ovine/caprine sero group II from the United Kingdom. BLAST for two isolates revealed 99% similarity to Acholeplasma laidlawii from India, another two were 99% similar to MmmLC strain from Sweden, two showed 98% similarity to Mycoplasma sp. Usp 120 from Brazil, and two isolates have a 97% - 99% similarity to M. mm. Jcv1 strain from the United States of America. Finally, one isolate showed similarity of 99% to Mycoplasma canadense strain from Italy. The findings support the hypothesis that ulcerative vulvitis and balanitis of Dorper sheep in South Africa (SA) is a multifactorial disease with involvement of different Mycoplasma species.

Extended survival times of Mycoplasma gallisepticum and Mycoplasma synoviae on kanekalon synthetic hair fibres.

The survival times of Mycoplasma gallisepticum (Mg) and Mycoplasma synoviae (Ms) on washed and unwashed natural and synthetic kanekalon hair samples over a 5-d period were evaluated using the color changing unit method for comparison with results of previous studies conducted on natural hair. Regardless of whether synthetic or natural hair samples prewashed with a disinfectant shampoo were spiked with Mg or Ms, all viable organisms rapidly dropped below a count of 1 × 10(1)/mL of culture. Unwashed natural hair seeded with a titer of approximately 1 × 10(6)/mL of viable Mg or Ms decreased to 6 × 10(5)/mL and 6 × 10(3)/mL, respectively, by 4 h postseeding, but no viable Mg or Ms were detected on natural hair from 8 h onwards. By contrast, the titers of Mg and Ms on synthetic hair did not decline from the initial 1 × 10(6)/mL seed dose up to 96 h postseeding, and, in fact, viable Mg and Ms was still detectable at 9 d postinfection. Application of a real-time quantitative single-tube duplex PCR assay confirmed that no proliferation of Mg or Ms had occurred on the synthetic hair samples, the cells simply remained viable. The unexpected finding that Mg and Ms survive for extended periods on synthetic kanekalon hair fibers raises the question of whether attachment to a surface is a prerequisite for the survival and persistence of Mg and Ms in the extra-host environment. Future studies should be aimed at determining whether other synthetic hair types or indeed other types of plastics commonly found in the poultry house offer similar survival advantages to mycoplasmas.