Retrospective study on the surveillance on dairy cows infective abortions in Northeastern Italy from 2006 to 2019

Objectives: Bovine abortion is an important cause of economic loss in dairy cattle, and has important implications in public veterinary health. Veneto region, in Northeastern Italy, has implemented since year 2006 an official surveillance plan on abortion in dairy cattle. The aim of this study is to describe the results of this surveillance, from 2006 to 2019, and to provide information about the occurrence of abortive pathogens and their prevalence. Material and methods: Aborted fetuses, accompanied by the dam’s blood sample, were delivered to the Regional State Veterinary Laboratory (IZSVe), and submitted to a panel of laboratory tests. The cows’ sera were tested for antibodies against Neospora caninum, Chlamydophila abortus, Coxiella burnetii, IBR virus, and BVD non structural protein NS2-3 by mean of commercial ELISA tests, and to Brucella abortus and melitensis following the EU regulation mandatory method. Antibody against Coxiella burnetii were detected using also the complement fixation test according to OIE guideline. On all the fetuses were performed necroscopy, microbiological culture from abomasum, histopathology from lung, and detection, by PCR from spleen, of BVD virus, Chlamydia spp., and Coxiella. burnetii. Detection of Neospora caninum by PCR from the brain was performed only on fetuses older than four month. Brucella spp isolation was carried out only if the abortion occurred after the fifth pregnancy month; while Campylobacter fetus isolation was performed on abortions occurred before the fifth month. A PCR for the detection of Schmallenberg virus from the brain was introduced after year 2013. Results: During these years (2006-2019) 4,562 bovine abortions were delivered to IZSVe, 668 of them were under the fifth month of gestation (14.6%). The most of fetuses delivered were autolytic (62.7%), without macroscopic lesions (30.8%) or mummified (4.5%). Histologically lung inflammatory lesions were present in 32.8% of cases. An infective agent was detected in 1451 fetuses (31.8%). Neospora caninum was the most frequent specific abortion agent isolated (22.2%), followed by BVD virus (5.7%), Coxiella. Burnetii (4.7%) and Chlamydia spp (0.7%). Schmallenberg virus was detected only in 3 fetuses delivered respectively in year 2012, 2013 and 2014, but only one showed congenital abnormalities (limbs arthrogryposis and jaw malformation). Microbiological culture was considered positive only when specific abortifacient pathogens were isolated: according to this criteria the 13% had a culture positive test. Among the bacteriological agents isolated the most relevant were T. pyogenes (47.4%), Bacillus spp. (29.4%), Streptococcus spp. (15.8%), L. monocytogenes and fungi (1.9%), P. multocida (1.7%), Salmonella spp. (1.1%), M. haemolytica (0.7%), Corynebacterium spp. (0.2%). Campylobacter fetus was isolated in one abortion and Brucella spp. was never isolated. Serological tests showed a high percentage of cows had antibodies against BVD virus (44.8%), Chlamydophila abortus (41.3%), Neospora caninum (33.2%); IBR virus (25.4%), C. burnetii (15.8%). All tested sera and abortions were negative for Brucella spp. The agreement between serological test and PCR for Neospora caninum was substantial (Cohen’s kappa (k) = 0.667, while the agreement for BVD virus and C. burnetii was slight (k = 0.11; k = 0.16). Conclusions: In our opinion, the abortion surveillance program provided many useful and interesting information about the health status of dairy farms and the diagnostic methods suitable for abortion diagnosis. Necroscopy findings showed the low prevalence of specific macroscopic lesion in fetuses, highlighting the importance to use a standardized protocol including tests for detection of the most relevant abortion agents. Infective abortions should be expected approximately in 30% of cases, several other causes should be considered as the source of pregnancy interruption. In order of importance Neospora caninum is the major abortive pathogen in Northeastern Italy, bacterial or fungal agents are the second, with prevalence ranging from 12-14%, while BVD virus and Coxiella. burnetii are less likely to be isolated

Isolation of Clostridium perfringens from starving juvenile sturgeons with severe enteritis

In November 2020, a mortality episode in juvenile sturgeons occurred in a hatchery in Northern Italy, associated with severe abdomen dilatation and peculiar behavioral alteration, characterized by upside-down surface swimming. Juveniles (4-5 months old, average weight ± 25g) of Siberian and Russian sturgeons (Acipenser baerii and A. gueldenstaedtii) and hybrid sturgeons GUBA (A. gueldenstaedtii x A. baerii), were promiscuously maintained in concrete hatchery tanks supplied by well water (15 °C, O₂ 7 ppm, CO₂ 12 ppm), and fed at 0.4% of body weight per day. The outbreak resulted in cumulative mortality of 25%. Thirty moribund sturgeons were collected, euthanized with an overdose of MS-222, and underwent necropsy followed by histological, bacteriological, and virological investigations. Main macroscopic findings included diffuse and severe bloating of gastrointestinal tracts due to foamy contents, with severe thinning and stretching of the intestinal wall, absence of visceral fat, and small size of the hepatopancreas. Histology revealed variable degrees of attenuation, sloughing, and necrosis of the intestinal epithelium, associated with bacterial aggregates, and hepatocellular degeneration. All specimens were negative for Herpesviruses by WSSK-1 cell culture, and Iridovirus (AcIV-E) and Betanodavirus by molecular methods. Bacteriological examination revealed Plesiomonas shigelloides and Cetobacterium somerae in a subset of intestines, while other organs yielded negative results. Based on recent literature, an intestinal dysmicrobism was suspected, and anaerobic gram+ bacteria were investigated. Clostridium perfringens was isolated from the intestines, and specific PCRs identified the toxinotype A and the β2 toxin gene. The quantity of food was raised to 1.5% of body weight, and after 5 days the abnormal behavior and mortality ceased. The analyses were repeated after 12 weeks from the food increase and showed no alterations including negative results for C. perfringens isolation. Therefore, we hypothesize that underfeeding may have led to an imbalance in intestinal microbiota, favoring the C. perfringens infection, which was successfully controlled through management improvement. The importance of intestinal microbiota in sturgeons, of which the genera Clostridium is one of the main components, has recently been highlighted and, although this will need further validation, the increased diet in this case was successful and possibly restored the microbiota

No viable bacterial communities reside in the urinary bladder of cats with feline idiopathic cystitis

Urinary microbial diversities have been reported in humans according to sex, age and clinical status, including painful bladder syndrome/interstitial cystitis (PBS/IC). To date, the role of the urinary microbiome in the pathogenesis of PBS/IC is debated. Feline idiopathic cystitis (FIC) is a chronic lower urinary tract disorder affecting cats with similarities to PBS/IC in women and represents an important problem in veterinary medicine as its aetiology is currently unknown. In this study, the presence of a bacterial community residing in the urinary bladder of cats with a diagnosis of FIC was investigated. Nineteen cats with clinical signs and history of FIC and without growing bacteria in standard urine culture were included and urine collected with ultrasound-guided cystocentesis. Bacterial community was investigated using a culture-dependent approach consisted of expanded quantitative urine culture techniques and a culture-independent approach consisted of 16S rRNA NGS. Several methodological practices were adopted to both avoid and detect any contamination or bias introduced by means of urine collection and processing which could be relevant due to the low microbial biomass environment of the bladder and urinary tract, including negative controls analysis. All the cats included showed no growing bacteria in the urine analysed. Although few reads were originated using 16S rRNA NGS, a comparable pattern was observed between urine samples and negative controls, and no taxa were confidently classified as non-contaminant. The results obtained suggest the absence of viable bacteria and of bacterial DNA of urinary origin in the urinary bladder of cats with FIC