Sample origin.

<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085656#pone-0085656-g001" target="_blank">Figure 1</a> shows the Germany-wide origin of the 5,229 wound swabs from dogs, cats and horses. Areas are shaped in color with regard to the sample frequency. Black dots represent the sample origin with regard to the postal code. The dot size displays the submission frequency of each veterinary practice/clinic.</p

Overview of lineage-diversity among MRSA from dogs, cats and horses.

<p>Overview of lineage-diversity among MRSA from dogs, cats and horses.</p

<i>Spa</i> type frequency and predicted clonal complexes based on <i>spa</i> typing and MLST for representative MRSA from wound infections of canine, feline and equine origin in Germany.

<p><i>Spa</i> type frequency and predicted clonal complexes based on <i>spa</i> typing and MLST for representative MRSA from wound infections of canine, feline and equine origin in Germany.</p

<i>S. aureus</i> proportion in wound samples from companion animals.

<p><i>S. aureus</i> proportion in wound samples from companion animals.</p

Phenotypic resistance for 241 MRSA grouped according to their clonal complexes.

<p>Number (n) and percentage (%) of resistant strains according to VITEK®2 system (bioMérieux, Germany).</p><p>Abbreviations: GEN: gentamicin, KAN: kanamycin, ENR: enrofloxacin, MAR: marbofloxacin, ERY: erythromycin, CLI: clindamycin, TET: tetracycline, NIT: nitrofurantoin, CHL: chloramphenicol and SXT: trimethoprim- sulfamethoxazole.</p

Results from Gram-negative indicator pathogen screening of equine patients at hospital admission.

<p>Results from Gram-negative indicator pathogen screening of equine patients at hospital admission.</p

Genomic comparison of the DNA sequences between <i>orf</i>X (rRNA-methyltransferase-like gene) and the <i>orf</i>Y-like gene of the <i>S</i>. <i>stepanovicii</i> strains IMT28705 (<i>mec</i>C-positive) with CCM7717 (<i>mec</i>C-negative).

<p>Direct repeats (DR) are indicated by red arrowheads, conserved DNA regions are shown by dark green color; more dissimilar sequences are indicated with light green. A remarkable divergence in the genomic structure downstream of the bacterial chromosomal attachment site (<i>att</i>B) is obvious, indicating a genomic “hot spot” for integration and excision of foreign DNA in <i>S</i>. <i>stepanovicii</i>. In addition, a blastn search (12/2014) revealed an absolutely low degree of nucleotide sequence similarities for this region of CCM7717 (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0147150#pone.0147150.s001" target="_blank">S1 Table</a>).</p

PFGE-analysis of ESBL-producing <i>E</i>. <i>coli</i> isolated from specimens obtained from horses at hospital admission.

<p>Dendrogram (percent similarity) showing DNA restriction pattern after digestion with XbaI for 41 <i>E</i>. <i>coli</i> isolated from horses directly at hospital admission. PFGE analysis by use of bionumerics® (unweighted-pair group method using average linkages), dice coefficient, 1.5% tolerance and 0.5% optimization indicated limited clonal relatedness. Antimicrobial susceptibility testing results VITEK®2 system (BioMérieux, Germany) for all ESBL-producing isolates revealed that multi-drug resistance is common. Plain numbers = susceptible-, bold = resistant-, underlined = intermediate phenotype. Abbreviations: Horse ID, individual number for each enrolled equine patient; OW, horse of the open wound group; C, horse of the colic group; IMT ID, strain collection number at IMT; ST, sequence type; AMP, ampicillin; AMC, amoxicillin-clavulanic acid; PIP, piperacillin; CFL, cephalexin; CPD, cefpodoxim; CEF, cephalexin; AN, amikacin; GM, gentamicin; ENR, enrofloxacin; MAR, marbofloxacin; TET, tetracycline; FM, nitrofurantoin; C, chloramphenicol; SXT, trimethoprim-sulfamethoxazole.</p

Maximum likelihood tree based on the maximum common genome (MCG).

<p>Maximum likelihood tree showing the relatedness of the strains based on their genome sequences together with their corresponding Sequence Type Complex (STC). The occurrences and distribution of <i>bla</i>_CTX-M-1, <i>bla</i>_CTX-M-24 and <i>bla</i>_SHV-12 in ESBL-producing <i>E</i>. <i>coli</i> obtained from horses at hospital admission is marked with black squares. While a general broad genomic heterogenicity is obvious, two genetic backgrounds are dominating (STC10 and STC1250).</p

Extended-spectrum beta-lactamase (ESBL)-producing <i>Escherichia coli</i> and <i>Acinetobacter baumannii</i> among horses entering a veterinary teaching hospital: The contemporary "Trojan Horse"

<div><p>Pathogens frequently associated with multi-drug resistant (MDR) phenotypes, including extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) and <i>Acinetobacter baumannii</i> isolated from horses admitted to horse clinics, pose a risk for animal patients and personnel in horse clinics. To estimate current rates of colonization, a total of 341 equine patients were screened for carriage of zoonotic indicator pathogens at hospital admission. Horses showing clinical signs associated with colic (n = 233) or open wounds (n = 108) were selected for microbiological examination of nostril swabs, faecal samples and wound swabs taken from the open wound group. The results showed alarming carriage rates of Gram-negative MDR pathogens in equine patients: 10.7% (34 of 318) of validated faecal specimens were positive for ESBL-E (94%: ESBL-producing <i>Escherichia coli</i>), with recorded rates of 10.5% for the colic and 11% for the open wound group. 92.7% of the ESBL-producing <i>E</i>. <i>coli</i> were phenotypically resistant to three or more classes of antimicrobials. <i>A</i>. <i>baumannii</i> was rarely detected (0.9%), and all faecal samples investigated were negative for <i>Salmonella</i>, both directly and after two enrichment steps. Screening results for the equine nostril swabs showed detection rates for ESBL-E of 3.4% among colic patients and 0.9% in the open wound group, with an average rate of 2.6% (9/340) for both indications. For all 41 ESBL-producing <i>E</i>. <i>coli</i> isolated, a broad heterogeneity was revealed using pulsed-field gel electrophoresis (PFGE) patterns and whole genome sequencing (WGS) -analysis. However, a predominance of sequence type complex (STC)10 and STC1250 was observed, including several novel STs. The most common genes associated with ESBL-production were identified as <i>bla</i>_CTX-M-1 (31/41; 75.6%) and <i>bla</i>_SHV-12 (24.4%).</p><p>The results of this study reveal a disturbingly large fraction of multi-drug resistant and ESBL-producing <i>E</i>. <i>coli</i> among equine patients, posing a clear threat to established hygiene management systems and work-place safety of veterinary staff in horse clinics.</p></div