Scielo RSS <![CDATA[Austral journal of veterinary sciences]]> vol. 54 num. 2 lang. es <![CDATA[SciELO Logo]]> <![CDATA[Non-O157 Shiga toxin-producing <em>Escherichia coli</em> with potential harmful profiles to humans are isolated from the faeces of calves in Uruguay]]> ABSTRACT Shiga toxin-producing Escherichia coli (STEC) infections are responsible for acute illnesses and deaths in humans. Cattle and humans are exposed to STEC through faeces and contaminated food and water. The big six and O157 STEC serogroups are important food and water-borne human pathogens. Additionally, Stx1a, Stx2a and Stx2c subtypes are highly associated with the haemolytic uremic syndrome. This study aimed to determine Shiga toxin-subtypes, the presence of antigen 43 families, the genotypic and phenotypic antimicrobial susceptibility profiles, O-serogrouping, phylotypes and phylogenetic relatedness of STEC of calf origin. Sixteen STEC isolates from calf origin were analysed. PCR was performed to determine Stx subtypes, serogroups, the presence of ag43 I and II and phylotypes. The antimicrobial profile was evaluated and the presence of PMQR and fosfomycin genes was determined by PCR. The clonal relatedness of STEC was studied by PFGE. The genotypes stx1a+c, stx1a+, stx1a+/stx2e+, stx1a+c/stx2e and stx2a were detected. Ag43 II was the most prevalent among subfamilies. STEC isolates were serotyped as O103 (n=5) and O111 (n=6). Fifty per cent of the isolates were classified as B1 phylogroup, 4/16 as E, 1/16 as C, and 1/16 as F. Non-O157 STEC isolates showed a high level of diversity, independent of the geographical and farm-origin. Isolates were resistant to ampicillin, ciprofloxacin, gentamicin, and fosfomycin-trometamol. The gene fosA7 was detected in 1 isolate. The virulence profiles, including Shiga toxin-subtypes and serogroups, denote the potential harm of non-O157 STEC isolates to humans. We also confirmed that circulating non-O157 STEC from cattle present genetic heterogeneity and are susceptible to antibiotics. <![CDATA[Captive collared peccary carries ESBL-producing diarrheagenic <em>Escherichia coli</em> pathotypes]]> ABSTRACT Collared peccaries (Pecari tajacu) roam the forests of natural areas in America. Wild collared peccary appears to be a carrier for bacteria associated with infections in humans and animals, however, the presence of diarrheagenic E. coli (DEC) pathotypes has not been studied in the captive collared peccary. This study aimed to study the prevalence of DEC, the susceptibility to antibiotics, and the frequency of β-lactamase genes (ESBL) in captive collared peccary faeces. DEC strains were identified in 44.4% (N=56) of the E. coli-carrying peccaries under study. The following DEC strains were identified: ETEC (35.7%), EAEC (28.6%), STEC (21.4%) and EPEC (14.3%). Most of the identified DEC strains belonged to clade I (58.9%). The genetic marker rfbO157 was not found in any STEC strain. Of the DEC strains, 67.9% (N=38) were considered multidrug resistant and were not susceptible to ampicillin (75%) nor to carbenicillin (51.8%). The combination of the genes blaTEM + blaCTX and blaTEM + blaSHV (6 strains respectively) was the most frequent among the DEC strains. It is concluded that captive collared peccaries are carriers of DEC strains that carry β-lactamase blaTEM, blaCTX and blaSHV genes and are not susceptible to ampicillin. Given the current efforts of the Wildlife Management Units (WMU) to reintroduce the collared peccary into natural areas, these captive collared peccaries act as carriers of diarrheagenic E. coli strains and therefore a potential source of gastrointestinal disease in humans and animals. <![CDATA[Domestic dog and alien North American mink as reservoirs of infectious diseases in the endangered Southern river otter]]> ABSTRACT Introduced alien carnivores are host to infectious diseases that may become an important threat for native carnivore species conservation. Canine distemper virus (CDV) is thought to be transmitted among individuals by direct contact and to present viral dynamics associated with a density-dependent multi-host carnivore community. In contrast, Canine Parvovirus (CPV) is mostly transmitted by indirect contact and does not depend only on the density, but also on the social behaviour of infected as well as susceptible hosts. The objective of this study was to assess how introduced American mink (Neovison vison) can act as a bridge-host between domestic dog (Canis familiaris) and Southern river otter (Lontra provocax) in different dog and mink population density scenarios. Our data show that otters are seropositive to both CDV and PV, as well as a molecular identity to Parvovirus in dogs and minks. Furthermore, a strong positive correlation between dog population density and observed seroprevalence of CDV in dogs, minks, and otters was recorded. For Parvovirus, the observed seroprevalence in mink and otters was not correlated to a higher dog population density, but instead a relationship between dog and mink population densities and social behaviour. Our results suggest that introduced American mink and domestic dogs are reservoirs of CDV and PV, both being diseases of major importance for the conservation of native endangered carnivores in Patagonia. <![CDATA[Detection of pathogenic leptospira as a cause of abortion in cattle-observations on diagnosis]]> ABSTRACT. Leptospirosis is a zoonotic infectious disease caused by members of the genus Leptospira, which affects domestic and wild animals. Cases of abortion in cattle have been associated with this infection, but these are often not adequately confirmed. To determine the best diagnostic strategy for leptospirosis-associated cases of abortion, we evaluated some of the techniques used in the veterinary laboratory and found that the key issues are sample type and timing. In a retrospective anatomical and histopathological analysis, we studied 42 aborted foetuses with lesions consistent with leptospirosis to check for the presence of pathogenic leptospira by qPCR, as well as ascertaining the serologic status of the cows. In addition, in a prospective analysis, cows that had aborted foetuses were analysed within 2 days of the event by MAT and qPCR using blood and urine samples. Analysis of the foetuses indicated that only 14.3% of the selected cases (6 of 42) gave a positive qPCR result. Regarding cows that had recently aborted foetuses, 4 out of 11 sampled showed a positive qPCR, while MAT tests showed only negative results. The evidence provided in this study indicates that the time that has elapsed since a clinical event has occurred and the type of clinical sample taken are key elements in the successful confirmation of pathogenic leptospira as the cause of abortion. <![CDATA[Evaluation of the efficacy of essential oils of <em>Lavandula angustifolia</em> and <em>Eucalyptus globulus</em> for the control of <em>Varroa destructor</em> in <em>Apis mellifera</em>: A randomised field study]]> ABSTRACT Varroa destructor is the most harmful and widespread parasite that spreads disease in bees. Eucalyptus spp essential oils (EOs) have proved effective against V. destructor. Additionally, Lavender spp EOs treatment has caused mite mortality rates of 95% to 97% for the same parasite. In this study, 20 mL of each oil or the placebo were distributed on two sheets of papier-mâché located on the frames of the brood chamber inside each hive. The miticidal effects of Lavandula angustifolia and Eucalyptus globulus EOs were analysed. Parasitic load and mite fall were evaluated under field conditions. The mean infestation rate obtained from each of the three treatment groups at the beginning of the study was less than 3.6%. Then, the infestation rate increased gradually in each group until day 36. The infestation rate in the group treated with L. angustifolia was lower than in the control group by over two per cent and never exceeded 10%; the differences between the control group and the L. angustifolia group were statistically significant (P&lt;0.05). In conclusion, L. angustifolia EO provided effective parasite control starting at the second treatment dose. However, E. globulus EO did not show a consistent parasite control. Further studies should consider the evaluation of EOs for the control of V. destructor in different weather conditions and other treatment delivery systems. <![CDATA[Aneurysm of the pulmonary artery in a sheep with pulmonary adenocarcinoma]]> ABSTRACT Aneurysm of the pulmonary artery is a rare condition in animals, and to our knowledge it has never been reported in association with pulmonary neoplasia. This report describes a case of an adult female sheep of the “Churra Galega Bragançana” breed with an aneurysm of the pulmonary artery associated with lung cancer (ovine pulmonary adenocarcinoma).