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In de eerste helft van dit artikel worden diverse aspecten van zoönosen toegelicht aan de hand van voorbeelden. De tweede helft beschrijft de ervaringen vanuit het Veterinair Microbiologisch Diagnostisch Centrum (VMDC) van de Faculteit Diergeneeskunde nadat in november 2016 onverwacht Brucella werd geïsoleerd in de routine diagnostiek. Dit had serieuze gevolgen voor de analisten en heeft geleid tot aanpassing van de werkwijze.

This study surveyed the prevalence of massive numbers of Cyniclomyces guttulatus in faecal samples from healthy dogs (18%) and dogs with chronic diarrhoea (14%) suggesting that this yeast has no clinical significance. Subsequently, a total of 57 referred dogs with chronic diarrhoea were selected because they excreted massive numbers of C. guttulatus and their initial diagnostic work-up yielded no other direct clues explaining their diarrhoea. Treatment with nystatin did not result in any clinical response in 36 out of these 57 dogs (63%), although they no longer shed the yeast. However, a response was noted in the remaining 21 (37%) dogs: 13 were ‘responders’, in that their diarrhoea subsided for more than two weeks and the faeces were cleared of the yeast. However, three of these dogs relapsed repeatedly, with signs of diarrhoea and massive shedding of the yeast. The other eight dogs were ‘incomplete responders’, whereby faecal quality initially normalised, but diarrhoea relapsed within two weeks, whilst still not shedding the yeast. In these cases, further diagnostic work up revealed other co-causes of diarrhoea. It was concluded that there was no direct evidence that C. guttulatus is a primary pathogen. However, the results of the prospective treatment study suggest that a possible role in a minority of cases, perhaps as an opportunist, cannot be ruled out.

Tritrichomonas foetus-infecties bij katten verlopen vaak symptoomloos, maar kunnen ook tot chronische colitis leiden. Klinische klachten worden vooral gevonden bij jonge raskatten. Of dit te maken heeft met de leefomstandigheden van raskatten of met een verhoogde gevoeligheid is niet duidelijk. De parasiet kan via drie verschillende diagnostische methoden aangetoond worden, waarbij een juiste monstername cruciaal is om de kans op vals negatieven te verkleinen. Na een positieve testuitslag kan ronidazol ingezet worden als therapie. Het middel is echter niet geregistreerd voor katten en kan neurotoxisch zijn. Omdat T. foetus geen omgevingsresistente cysten vormt, verloopt de transmissie van kat op kat via direct of nauw indirect contact. De trophozoïeten blijken, in een experimentele setting, enkele dagen te kunnen overleven onder vochtige omstandigheden bij kamertemperatuur. Als preventie- en bestrijdingsmaatregelen moet vooral aandacht geschonken worden aan een goede kattenbak-hygiëne en huishoudelijk schoonmaken. Omdat therapie en bestrijding arbeidsintensief zijn en in veel gevallen niet het gewenste resultaat opleveren, zijn preventieve maatregelen om insleep in te voorkomen van groot belang.

Objectives To investigate the occurrence and characteristics of extended-spectrum β-lactamase (ESBL)- and AmpC-producing Enterobacteriaceae isolates in clinical samples of companion animals and horses and compare the results with ESBL/AmpC-producing isolates described in humans. Methods Between October 2007 and August 2009, 2700 Enterobacteriaceae derived from clinical infections in companion animals and horses were collected. Isolates displaying inhibition zones of ≤25 mm for ceftiofur and/or cefquinome by disc diffusion were included. ESBL/AmpC production was confirmed by combination disc tests. The presence of resistance genes was identified by microarray, PCR and sequencing, Escherichia coli genotypes by multilocus sequence typing and antimicrobial susceptibility by broth microdilution. Results Sixty-five isolates from dogs (n = 38), cats (n = 14), horses (n = 12) and a turtle were included. Six Enterobacteriaceae species were observed, mostly derived from urinary tract infections (n = 32). All except 10 isolates tested resistant to cefotaxime and ceftazidime by broth microdilution using clinical breakpoints. ESBL/AmpC genes observed were blaCTX-M-1, -2, -9, -14, -15,blaTEM-52, blaCMY-2 and blaCMY-39. blaCTX-M-1 was predominant (n = 17). blaCTX-M-9 occurred in combination with qnrA1 in 3 of the 11 Enterobacter cloacae isolates. Twenty-eight different E. coli sequence types (STs) were found. E. coli carrying blaCTX-M-1 belonged to 13 STs of which 3 were previously described in Dutch poultry and patients. Conclusions This is the first study among a large collection of Dutch companion animals and horses characterizing ESBL/AmpC-producing isolates. A similarity in resistance genes and E. coli STs among these isolates and isolates from Dutch poultry and humans may suggest exchange of resistance between different reservoirs.