Sarah Schmitt

European multicenter study on antimicrobial resistance in bacteria isolated from companion animal urinary tract infections

BackgroundThere is a growing concern regarding the increase of antimicrobial resistant bacteria in companion animals. Yet, there are no studies comparing the resistance levels of these organisms in European countries. The aim of this study was to investigate geographical and temporal trends of antimicrobial resistant bacteria causing urinary tract infection (UTI) in companion animals in Europe. The antimicrobial susceptibility of 22 256 bacteria isolated from dogs and cats with UTI was determined. Samples were collected between 2008 and 2013 from 16 laboratories of 14 European countries. The prevalence of antimicrobial resistance of the most common bacteria was determined for each country individually in the years 2012–2013 and temporal trends of bacteria resistance were established by logistic regression.ResultsThe aetiology of uropathogenic bacteria differed between dogs and cats. For all bacterial species, Southern countries generally presented higher levels of antimicrobial resistance compared to Northern countries. Multidrug-resistant Escherichia coli were found to be more prevalent in Southern countries. During the study period, the level of fluoroquinolone-resistant E. coli isolated in Belgium, Denmark, France and the Netherlands decreased significantly. A temporal increase in resistance to amoxicillin-clavulanate and gentamicin was observed among E. coli isolates from the Netherlands and Switzerland, respectively. Other country-specific temporal increases were observed for fluoroquinolone-resistant Proteus spp. isolated from companion animals from Belgium.ConclusionsThis work brings new insights into the current status of antimicrobial resistance in bacteria isolated from companion animals with UTI in Europe and reinforces the need for strategies aiming to reduce resistance.

Towards harmonised procedures in wildlife epidemiological investigations: A serosurvey of infection with Mycobacterium bovis and closely related agents in wild boar (Sus scrofa) in Switzerland

Bovine tuberculosis (bTB) is a (re-)emerging disease in European countries, including Switzerland. This study assesses the seroprevalence of infection with Mycobacterium bovis and closely related agents in wild boar (Sus scrofa) in Switzerland, because wild boar are potential maintenance hosts of these pathogens. The study employs harmonised laboratory methods to facilitate comparison with the situation in other countries. Eighteen out of 743 blood samples tested seropositive (2.4%, CI: 1.5-3.9%) by ELISA, and the results for 61 animals previously assessed using culture and PCR indicated that this serological test was not 100% specific for M.xa0bovis, cross-reacting with M.xa0microti. Nevertheless, serology appears to be an appropriate test methodology in the harmonisation of wild boar testing throughout Europe. In accordance with previous findings, the low seroprevalence found in wild boar suggests wildlife is an unlikely source of the M.xa0bovis infections recently detected in cattle in Switzerland. This finding contrasts with the epidemiological situation pertaining in southern Spain.

Antimicrobial susceptibility of Brachyspira hyodysenteriae in Switzerland.

INTRODUCTIONnBrachyspira (B.) hyodysenteriae is the causative agent of swine dysentery (SD), a severe mucohaemorrhagic diarrheal disease in pigs worldwide. So far, the antimicrobial susceptibility patterns of B. hyodysenteriae in Switzerland have not been investigated. Therefore, a panel of 30 porcine B. hyodysenteriae isolates were tested against 6 antimicrobial agents by using the VetMIC Brachy panel, a broth microdilution test. Tiamulin and valnemulin showed high antimicrobial activity inhibiting all isolates at low concentrations. The susceptibility testing of doxycycline revealed values from ≤0.25 μg/ ml (47%) to 2 μg/ml (10%). The MIC values of lincomycin ranged between ≤0.5 μg/ml (30%) and 32 μg/ml (43%). For tylosin, 57% of the isolates could not be inhibited at the highest concentration of ≥128 μg/ml. The MIC values for tylvalosin were between ≤0.25 μg/ml (10%) and 8 μg/ml (20%). These findings reveal Switzerlands favourable situation compared to other European countries. Above all, tiamulin and valnemulin are still effective antimicrobial agents and can be further used for the treatment of SD.

A novel multiplex qPCR targeting 23S rDNA for diagnosis of swine dysentery and porcine intestinal spirochaetosis

BackgroundA multiplex qPCR targeting a 128xa0bp region on the 23S rDNA gene was developed for detection of Brachyspira (B.) hyodysenteriae and B. pilosicoli, the agents of swine dysentery (SD) and porcine intestinal spirochaetosis (PIS), together with a triplet of apathogenic Brachyspira spp. (B. innocens, B. intermedia, B. murdochii) in porcine feces. The multiplex qPCR was evaluated against a duplex PCR (La et al., J Clin Microbiol 41:3372–5, 2003).ResultsUsing DNA extracted from fecal culture, the multiplex qPCR showed excellent agreement with the duplex PCR (κu2009=u20090.943 and 0.933). In addition, thanks to the three probes whereof one detecting the apathogenic Brachyspria spp., a more diversified overview of the brachyspiral flora in porcine fecal samples can be delivered as a part of the routine diagnostic. The multiplex qPCR with a limit of detection of 5–10 genomic equivalents (GE) per reaction (6u2009×u2009102 GE per gram) allows reliable detection of Brachyspira species directly from fecal swab DNA. In line with this, analysis of 202 fecal swabs in comparison with culture-based qPCR showed a high agreement for the causative agents of SD (B.hyodysenteriae: κu2009=u20090.853, sensitivity 87% specificity 98%).ConclusionThe novel multiplex qPCR is robust and has a high analytical sensitivity and is therefore suitable for high-throughput screening of porcine fecal swabs for the causative agents of SD. This assay can therefore be used for the direct proof of the pathogenic B. spp. in fecal swabs within the scope of a monitoring program.

Antimicrobial resistance, multilocus sequence types and virulence profiles of ESBL producing and non-ESBL producing uropathogenic Escherichia coli isolated from cats and dogs in Switzerland

Among 64 uropathogenic Escherichia coli (UPEC) isolated from 13 cats and 51 dogs, 35 were extended-spectrum beta-lactamase (ESBL) producers, and 29 were non-ESBL producers. Forty-six (71.9%) of the isolates were multidrug resistant (MDR). Among the ESBL producers, blaCTX-M-15 (nu202f=u202f17/48.6% of the blaESBLs), blaCTX-M-1 (nu202f=u202f10/28.6%), blaCTX-M-55 (nu202f=u202f4/11.4%), blaCTX-M-14 (nu202f=u202f3/8.6%), and blaCTX-M-27 (nu202f=u202f1/2.9%) were identified. The plasmid-mediated fluoroquinolone resistance genes aac(6)-Ib-cr, qnrB and the azithromycin resistance gene mph(A) were detected in 17 (26.6% of all isolates), one (1.6%) and in 13 (20.3%) respectively. The most frequent phylogenetic groups were C (nu202f=u202f19) and B2 (nu202f=u202f15). Twenty-six different sequence types (STs) were identified, with two being novel. The most frequent STs were ST410 (nu202f=u202f16/25%), ST131, and ST73 (both nu202f=u202f5/7.8%), and ST361 (nu202f=u202f4/6.3%). Ten (15.6%) of the STs have been associated with urinary tract infection (UTI) in humans, suggesting zoonotic potential. Among seven virulence-associated genes, fyuA was the most prevalent. The overall aggregate virulence factor (VF) score was highest for isolates belonging to phylogenetic group B2 (median aggregate VF score 6, mean score 5,5, range 3-7), and lowest for isolates belonging to phylogenetic group C (0/ 0.5/0-3). The most frequent ST in this study, ST410, harboured the lowest number of VF (0/0,3/0-2). VF scores were higher in NDR (4/3.8/3-4) than in MDR (1/1,9/0-7), and higher in non-ESBL producing isolates (3/3/0-7) than in ESBL producers (1/1,7/0-7). Our data advance our knowledge of the phenotypic and genotypic characteristics of UPEC in companion animals and their potential for infection, zoonotic transmission and dissemination of antimicrobial resistance determinants.

High Prevalence of Extended-Spectrum β-Lactamase Producing Enterobacteriaceae Among Clinical Isolates From Cats and Dogs Admitted to a Veterinary Hospital in Switzerland

Objectives This study aimed to identify and characterize extended-spectrum β-lactamase (ESBL) producing Enterobacteriaceae among clinical samples of companion animals. Methods A total of 346 non-duplicate Enterobacteriaceae isolates were collected between 2012 and 2016 from diseased cats (nu2009=u2009115) and dogs (nu2009=u2009231). The presence of blaESBL, PMQR genes, and the azithromycin resistance gene mph(A) was confirmed by PCR and sequencing of bla genes. Isolates were further characterized by antimicrobial resistance profiling, multilocus sequence typing, phylogenetic grouping, identification of mutations in the QRDR of gyrA and parC, and screening for virulence-associated genes. Results Among the 346 isolates, 72 (20.8%) were confirmed ESBL producers [58 Escherichia coli (E. coli), 11 Klebsiella pneumoniae (K. pneumoniae), and 3 Enterobacter cloacae]. The strains were cultured from urine (nu2009=u200945), skin and skin wounds (nu2009=u20098), abscesses (nu2009=u20096), surgical sites (nu2009=u20096), bile (nu2009=u20094), and other sites (nu2009=u20093). ESBL genes included blaCTX-M-1, 14, 15, 27, 55, and blaSHV-12, predominantly blaCTX-M-15 (54.8%, 40/73), and blaCTX-M-1 (24.7%, 18/73). Further genes included qnrB (4.2%, 3/72), qnrS (9.7%, 7/72), aac(6’)-Ib-cr (47.2%, 34/72), and mph(A) (38.9%, 28/72). Seventeen (23.6%) isolates belonged to the major lineages of human pathogenic K. pneumoniae ST11, ST15, and ST147 and E. coli ST131. The most prevalent ST was E. coli ST410 belonging to phylogenetic group C. Conclusion The high prevalence of ESBL producing clinical Enterobacteriaceae from cats and dogs in Switzerland and the presence of highly virulent human-related K. pneumoniae and E. coli clones raises concern about transmission prevention as well as infection management and prevention in veterinary medicine.

Bovine Fetal Placenta During Pregnancy and the Postpartum Period

Bovine abortion is a worldwide problem, but despite extensive histopathologic and molecular investigations, the cause of abortion remains unclear in about 70% of cases. Cellular debris is a commonly observed histopathologic finding in the fetal placenta and is often interpreted as necrosis. In this study, the nature of this cellular debris was characterized, and histologic changes in the normal fetal placenta during pregnancy and after delivery were assessed. In addition, the presence of the most common abortifacient pathogens in Switzerland (Chlamydiaceae, Coxiella burnetii, Neospora caninum) was tested by polymerase chain reaction. We collected 51 placentomes and 235 cotyledons from 41 and from 50 cows, respectively. In total, cellular debris was present in 48 of 51 (94%) placentomes and in 225 of 235 (96%) cotyledons, inflammation occurred in 1 of 51 (2%) placentomes and in 46 of 235 (20%) cotyledons, vasculitis was seen in 1 of 51 (2%) placentomes and 46 of 235 (20%) cotyledons, and 18 of 51 (35%) placentomes and 181 of 235 (77%) cotyledons had mineralization. The amount of cellular debris correlated with areas of positive signals for cleaved caspase 3 and lamin A. Therefore, this finding was interpreted as an apoptotic process. In total, 10 of 50 cotyledons (20%) were positive for C. burnetii DNA, most likely representing subclinical infections. The results of our study indicate that histologic features in the fetal placenta such as cellular debris, inflammation, vasculitis, and mineralization must be considered physiological processes during pregnancy and after delivery. Therefore, their presence in placentae of aborted fetuses must be interpreted with caution and might not be necessarily linked to an infectious cause of abortion.

Predominance of a macrolide-lincosamide-resistant Brachyspira hyodysenteriae of sequence type 196 in Swiss pig herds

Worldwide emergence of antimicrobial-resistant Brachyspira (B.) hyodysenteriae led us question whether specific clones are present in Switzerland. Fifty-one B. hyodysenteriae isolates originating from 27 different Swiss pig herds sampled between 2010 and 2017 were characterised. Multilocus sequence typing revealed the presence of four different sequence types (STs) ST6, ST66, ST196 and ST197 with ST196 being predominant. Antimicrobial susceptibility to six different antimicrobial agents was determined by measurement of the minimal inhibitory concentration by broth dilution. Isolates were examined for the presence of point mutations and genes known to be associated with antimicrobial resistance in B. hyodysenteriae by PCR and sequence analysis. Forty-one isolates belonging to ST6 (nu2009=u20091), ST66 (nu2009=u20094) and ST196 (nu2009=u200936) exhibited decreased susceptibility to macrolides and lincomycin associated with an A2058u2009T/G mutation in the 23S rRNA gene. One isolate of ST66 and five isolates of ST196 exhibited decreased susceptibility to doxycycline associated with a G1058C mutation in the 16S rRNA gene. The Swiss B. hyodysenteriae population is characterised by a low genetic diversity, with macrolide-lincosamide-resistant isolates of ST196 being predominant.

First report of nodular skin lesions caused by Mycobacterium nebraskense in a 9-year-old cat:

Case summary A 9-year-old cat was referred with multiple, raised, ulcerative skin nodules in the region of the neck and dorsal head. Histopathological findings of a biopsied nodule were granulomatous dermatitis and panniculitis without multinucleated giant cells or caseous necrosis. In addition, by Ziehl–Neelsen staining numerous acid-fast intracellular bacilli were observed within the lesions. Mycobacterial culture showed growth of rough scotochromogenic colonies after 3 weeks of incubation. Molecular characterisation of the isolate identified Mycobacterium nebraskense as the cause of the infection. No phenotypic resistance was detected for the antimycobacterial agents tested. The cat was successfully treated with a combination of surgical excision and a 12 week course of antimicrobial therapy, including rifampicin combined with clarithromycin. Relevance and novel information To our knowledge, this is the first documented case of mycobacterial granulomatous dermatitis and panniculitis due to M nebraskense infection in a cat. The successful surgical and antimycobacterial treatment regimen is described.

Population structure and virulence gene profiles of Streptococcus agalactiae collected from different hosts worldwide

Streptococcus agalactiae is a leading cause of morbidity and mortality among neonates and causes severe infections in pregnant women and nonpregnant predisposed adults, in addition to various animal species worldwide. Still, information on the population structure of S. agalactiae and the geographical distribution of different clones is limited. Further data are urgently needed to identify particularly successful clones and obtain insights into possible routes of transmission within one host species and across species borders. We aimed to determine the population structure and virulence gene profiles of S. agalactiae strains from a diverse set of sources and geographical origins. To this end, 373xa0S. agalactiae isolates obtained from humans and animals from five different continents were typed by DNA microarray profiling. A total of 242 different S. agalactiae strains were identified and further analyzed. Particularly successful clonal lineages, hybridization patterns, and strains were identified that were spread across different continents and/or were present in more than one host species. In particular, several strains were detected in both humans and cattle, and several canine strains were also detected in samples from human, bovine, and porcine hosts. The findings of our study suggest that although S. agalactiae is well adapted to various hosts including humans, cattle, dogs, rodents, and fish, interspecies transmission is possible and occurs between humans and cows, dogs, and rabbits. The virulence and resistance gene profiles presented enable new insights into interspecies transmission and make a crucial contribution to the identification of suitable targets for therapeutic agents and vaccines.