Valentina Stefanetti

A case of Candida guilliermondii abortion in an Arab mare

Ascending infections of equine uterus frequently result in placentitis and abortions; most of these infections are bacterial and are less commonly due to fungi. This report describes an abortion case in an Arab mare due to Candida guilliermondii that was diagnosed via cytological, histological, cultural and biomolecular assays. The histological lesions found were severe necrotizing placentitis associated with fetal pneumonia. To our knowledge this is the first case of C. guilliermondii abortion reported in equine species.

Is the horse a reservoir or an indicator of Coxiella burnetii infection? Systematic review and biomolecular investigation

The role of the horse in Coxiella burnetii infection has not been defined. Accordingly, a twofold approach was taken to further our knowledge on this topic: (1) conduct a systematic review of the literature to establish available evidence of C. burnetii infection in the horse; (2) undertake a biomolecular investigation of 122 cases of equine abortion, stillbirth and neonatal foal death, for the presence of C. burnetii using a PCR test targeting the IS1111 gene of C. burnetii. A review of the literature turned up seven studies that identified C. burnetii DNA in equine specimens, especially aborted fetuses, while an additional 34 studies sought to determine seroprevalence of the infection in the horse. A meta-analytical approach was taken to calculate a pooled mean seroprevalence in equines based on published studies. A seroprevalence of 15.8% (95% confidence interval: 9.6-23.0%) was obtained. This figure is comparable to those previously reported in other species, especially ruminants. None of the 122 cases of equine abortion, stillbirth or neonatal foal death were positive for C. burnetii DNA. C. burnetii has rarely been looked for in equine specimens in previous studies. Cases of equine abortion should be comprehensively investigated to assess the risk of abortion in a pregnant mare infected with C. burnetii. Consideration should also be given to the possible role of the horse as a source of the organism for other animal species including humans.

Phenotypic and genotypic characterization of canine pyoderma isolates of Staphylococcus pseudintermedius for biofilm formation

Biofilm-forming ability is increasingly being recognized as an important virulence factor in several Staphylococcus species. This study evaluated the biofilm-forming ability of sixty canine derived clinical isolates of S. pseudintermedius, using three phenotypic methods, microtiter plate test (MtP), Congo red agar method (CRA) and tube adherence test, and the presence and impact of biofilm-associated genes (icaA and icaD). The results showed that icaA and icaD genes were detected concomitantly in 55 (91.7%) of 60 isolates. A majority (88.3%) of the strains screened had matching results by the tube adherence test, MtP and PCR analysis. Better agreement (95%) was found between the PCR-based analysis and the CRA. Results of the icaA and icaD gene PCRs showed good agreement with CRA results, with a kappa of 0.7. Comparing the phenotypic methods, the statistical analysis showed that the agreement among the phenotypical tests using categorical data was generally good. Considering two classes (biofilm producer and biofilm non-producer), the percentage of matching results between the CRA method and the tube adherence test and between the CRA method and the MtP was 93.3%. A concordance of 100% was revealed between the MtP and the tube adherence test. The results indicate a high prevalence of the ica genes within S. pseudintermedius isolates, and their presence is associated with in vitro formation of a biofilm. A combination of phenotypic and genotypic tests is recommended for investigating biofilm formation in S. pseudintermedius.

DNA microarray assay and real-time PCR as useful tools for studying the respiratory tract Mycoplasma populations in young dairy calves

Purpose. With more than 120 species, the genus Mycoplasma is one of the largest taxa in the class Mollicutes, a group of micro‐organisms that are characterized by apparent simplicity and to which important animal pathogens belong. Mycoplasma bovis is the most frequently identified pathogenic Mycoplasma in cattle; however, the prevalence of other Mycoplasma species living in calves’ airways is poorly understood. The aim of this work was to characterize the respiratory tract mycoplasma populations in calves on one of the largest dairy farms in Italy using a real‐time PCR assay and a DNA microarray assay. Methodology. A total of 49 nasal swabs and 49 trans‐tracheal aspirations from non‐vaccinated veal calves were analysed. Genomic DNA was extracted from the samples and then tested using a real‐time PCR targeting the oppD gene of M. bovis and a DNA microarray that was able to identify more than 70 Mycoplasma species. Results. Forty‐two out of 49 calves tested positive for Mycoplasma spp. (85.7%). None of the samples tested positive for M. bovis. A majority (73.5%) of the 98 samples tested positive for M. dispar, while 8 samples tested positive for M. bovirhinis (8.2%). Conclusion. Our results expand our knowledge regarding the diversity of Mycoplasma populations in the respiratory airways of very young veal calves and add data regarding M. bovis prevalence in the Italian cattle population. However, the importance of these species in the respiratory diseases of calves still remains to be determined.

Stored Canine Whole Blood Units: What is the Real Risk of Bacterial Contamination?

Background Bacterial contamination of whole blood (WB) units can result in transfusion‐transmitted infection, but the extent of the risk has not been established and may be underestimated in veterinary medicine. Objectives To detect, quantify, and identify bacterial microorganisms in 49 canine WB units during their shelf life. Animals Forty‐nine healthy adult dogs. Methods Forty‐nine WB units were included in the study. Immediately after collection, 8 sterile samples from the tube segment line of each unit were aseptically collected and tested for bacterial contamination on days 0, 1, 7, 14, 21, 28, 35, and 42 of storage. A qPCR assay was performed on days 0, 21, and 35 to identify and quantify any bacterial DNA. Results On bacterial culture, 47/49 blood units were negative at all time points tested, 1 unit was positive for Enterococcus spp. on days 0 and 1, and 1 was positive for Escherichia coli on day 35. On qPCR assay, 26 of 49 blood units were positive on at least 1 time point and the bacterial loads of the sequences detected (Propionobacterium spp., Corynebacterium spp., Caulobacter spp., Pseudomonas spp., Enterococcus spp., Serratia spp., and Leucobacter spp.) were <80 genome equivalents (GE)/μL. Conclusions and Clinical Importance Most of the organisms detected were common bacteria, not usually implicated in septic transfusion reactions. The very low number of GE detected constitutes an acceptable risk of bacterial contamination, indicating that WB units have a good sanitary shelf life during commercial storage.

Detection of Equid herpesvirus type 2 and 5 DNA in uterine flushings of mares with reproductive disorders.

In recent years, there has been increasing evidence of the potential pathogenic significance of equine gammaherpesviruses in the horse. In humans, cattle and mice, gammaherpesviruses have already been associated with uterine infection. The aim of the present study was to investigate the presence of gammaherpesviruses in uterine flushings of mares with reproductive problems and to evaluate if there was a possible statistical association with clinical and laboratory findings in these cases. A total of 80 uterine flushings were collected from 61 mares with different reproductive problems and these were tested for equine herpesviruses (EHV) 1-5 by PCR. In the case of each mare in the study, the age, history of infertility, presence of anatomical defects in the reproductive tract, presence of systemic or local disease at time of sampling, phase in the oestrous cycle, post-partum interval, nature of uterine lavage performed (low versus large volume lavage), cytological and bacteriological examination results from the uterine flushing, and PCR herpesvirus results were recorded. Univariate analysis and multivariable logistic regression models were used to identify possible statistical associations and risk factors. Nine out of 61 mares (14.7%) had EHV-5 DNA in their uterine flushings. Co-infections with EHV-1 and EHV-2 were present in two cases. Of all the variables analyzed, only the cytological examination findings were associated with EHV-5 PCR positive results, both on univariate and multivariable analysis, especially in cases with an inflammation score of 3. It is postulated that presence of EHV-5 infection in the non-pregnant uterus may have a role to play in reproductive dysfunction and have a negative consequence on the pregnant uterus. Additional studies involving both healthy mares and mares with reproductive problems need to be performed, however, to elucidate whatever role equine gammaherpesviruses may play in the reproductive tract. This would be very worthwhile, since reproductive problems can have a significant impact on the equine breeding industry. Gaining a greater understanding of its causes could lead to new approaches for prevention and treatment.

Umbilical infections in foals: microbiological investigation and management

This study aims to investigate the bacteria involved in equine omphalitis and their susceptibility to antimicrobial drugs, and consequently to provide guidelines concerning the most suitable treatment protocol in accordance with the clinical, ultrasound and laboratory findings. Forty foals aged between one and 30 days were evaluated in the course of this investigation. An ultrasound examination of all umbilical remnants was carried out carefully in all foals; umbilical swabs were collected for bacteriological examination, and blood samples were collected for blood culture from 19 foals with fever and abnormal blood values. Bacterial omphalitis was observed in 95 per cent of foals and bacterial septicaemia was diagnosed in 11 cases. Enterobacteria and coccoid Gram-positive bacteria were isolated more frequently than Serratia marcescens, Pantoea agglomerans and Trueperella pyogenes. Omphalectomy was performed in 77.5 per cent of the foals examined; the remainder were treated only medically with antimicrobial drugs as recommended by antibiotic susceptibility testing performed for all bacteria isolated. Antibiotic therapy was successful in all foals that only received medical treatment; nevertheless, omphalectomy was performed in most cases particularly in situations of clinical decline despite antibiotic therapy and when involvement of umbilical vein, fever and joint disorders were observed.

High Expression of Endogenous Retroviral Envelope Gene in the Equine Fetal Part of the Placenta

Endogenous retroviruses (ERVs) are proviral phases of exogenous retroviruses that have co-evolved with vertebrate genomes for millions of years. Previous studies have identified the envelope (env) protein genes of retroviral origin preferentially expressed in the placenta which suggests a role in placentation based on their membrane fusogenic capacity and therefore they have been named syncytins. Until now, all the characterized syncytins have been associated with three invasive placentation types: the endotheliochorial (Carnivora), the synepitheliochorial (Ruminantia), and the hemochorial placentation (human, mouse) where they play a role in the syncytiotrophoblast formation. The purpose of the present study was to evaluate whether EqERV env RNA is expressed in horse tissues as well and investigate if the horse, possessing an epitheliochorial placenta, has “captured” a common retroviral env gene with syncytin-like properties in placental tissues. Interestingly, although in the equine placenta there is no syncytiotrophoblast layer at the maternal-fetal interface, our results showed that EqERV env RNA is highly expressed at that level, as expected for a candidate syncytin-like gene but with reduced abundance in the other somatic tissues (nearly 30-fold lower) thus suggesting a possible role in the placental tissue. Although the horse is one of the few domestic animals with a sequenced genome, few studies have been conducted about the EqERV and their expression in placental tissue has never been investigated.

Gammaherpesvirus infections in equids: a review

Although the first equine gammaherpesvirus was identified over 50 years ago, the isolation and characterization of other members of this virus group has been relatively recent. Even so, numerous clinical syndromes have been identified in equid species in association with these viruses. Equid gammaherpesviruses are a genetically heterogeneous viral subfamily, the function of which in host immune modulation and disease pathogenesis has not yet been elucidated. While they share similarities with gammaherpesviruses in humans, the role they play in their relationship with the host is the subject of continued interest and research. Their widespread presence in horses and other equid species provides a considerable challenge in linking them with particular clinical and pathological conditions and in defining their significance from a diagnostic and therapeutic viewpoint. The present review provides an update on the taxonomy, epidemiology, and clinical syndromes, especially respiratory, reported in association with gammaherpesvirus infection in horses, donkeys, and other equid species.

Detection of parvovirus and herpesvirus DNA in the blood of feline and canine blood donors

With the increase of blood transfusion in veterinary medicine, the presence of endemic viral agents in the blood should be carefully investigated. For this reason, the blood of feline and canine blood donors was screened to detect the presence of herpesviruses, especially gammaherpesviruses and parvoviruses, and to characterize the viruses detected. A retrospective cross-sectional study was performed on 31 cats and 54 dogs, enrolled as voluntary blood donors. Nested PCR was carried out to detect herpesvirus and parvovirus DNA. Sequencing and real-time PCR were used to confirm and quantify positive samples. The feline and canine samples were negative for the presence of herpesviruses. Fourteen specimens of blood (45.16%, 95% confidence interval, CI: 27.78-63.70) from feline blood donors and two (3.7%, 95% CI: 0.64-13.84) from canine blood donors were positive for parvovirus DNA. The percentage positivity was significantly different in cats and dogs (P < 0.0001), giving an odds ratio of 21.41 (95% CI: 4.4-103.9). The lack of detection of herpesviral DNA confirms previous results obtained in dogs, but contrasts with the evidence of the worldwide distribution of gammaherpesviruses in cats. Selection of blood donors is a useful tool adopted to reduce the risk of transfusion-transmitted infections for the majority of known microorganisms. The results obtained for parvovirus, however, confirm the presence of this pathogen in the blood of healthy cats, with a significant difference from dogs. The implications of the detection of parvoviral DNA in the blood of donors must be clarified in order to exclude the risk of transmission.