Surveillance of Antimicrobial Resistance of Escherichia coli Isolates from Intestinal Contents of Dairy and Veal Calves in the Veneto Region, Northeaster Italy.

This surveillance study aimed to estimate the proportion of antimicrobial resistant strains and antimicrobial resistance (AMR) profiles of E. coli isolates detected from the intestinal contents of veal and dairy calves in the Veneto Region, Northeaster Italy. Additionally, we investigated the differences in AMR profiles between dairy and veal calves over the period 2017-2022. Overall 1150 E. coli isolates were tested from calves exhibiting enteric disease, with 868 from dairy and 282 from veal calves. The percentage of resistant isolates to nine antimicrobials was notably higher in veal calves compared to dairy calves, except for ampicillin. Throughout the study period, we observed a significant increase in the proportion of resistant isolates to florfenicol, gentamycin, paromomycin, tetracycline and trimethoprim/sulfamethoxazole in dairy calves, while we did not detect any significant increase in the proportion of resistant isolates among veal calves. A substantial proportion (75.9%) of the isolated E. coli exhibited multi-drug resistance (MDR). The proportion of multi-drug resistant isolates was significantly higher in veal calves (91.7%) compared to dairy calves (74.3%) all through the surveillance period (2017-2022), with no significant variation in MDR proportion among veal calves between 2017 and 2022 but a significant increase among dairy calves.

Evaluation of antimicrobial and non-steroidal anti-inflammatory treatments for BRD on health and welfare in fattening bulls: a cross-sectional study.

Our study aimed to evaluate the effect of different treatments for BRD on health and welfare in fattening bulls. A total of 264 bulls were enrolled. Welfare was assessed on day 2 (T0) and day 15 (T1) after arrival. A decrease in the welfare level was observed from T0 to T1. All bulls were inspected clinically at T0 and T1 revealing an increase of skin lesions and lameness in T1. In both periods, a high incidence of respiratory disease was observed. A prevalence of 79.55% and 95.45% of Mycoplasma bovis using RT-PCR and culture at T0 and T1 respectively was observed. Blood samples were collected for haematology at T0 and T1. At T0, 36 animals were individually treated for BRD with an antimicrobial (IT), 54 received a metaphylactic treatment with tulathromycin (M), 150 received a metaphylactic treatment with tulathromycin plus a second antimicrobial (M + IT) whereas 24 were considered healthy and therefore not treated (NT). Additionally, 128 were treated with a non-steroid anti-inflammatory (NSAID). Neutrophils of M + IT were significantly higher than groups NT and M and the lymphocytes of M + IT were significantly lower than that of IT. White blood cells, neutrophils and N/L ratio of animals treated with an NSAID was significantly higher than that not treated. Lung inspection of 172 bulls at the abattoir indicated that 92.43% presented at least one lung lesion. A statistically significant effect of the NSAID treatment on the lung lesions was observed. Our findings indicate that BRD was a major welfare and health concern and evidence the difficulties of antimicrobial treatment of M. bovis.

The oriental hornet (Vespa orientalis) as a potential vector of honey bee's pathogens and a threat for public health in North-East Italy.

BACKGROUND: Oriental hornets are large predatory hymenoptera that occur in the southern part of Asia and the southeastern Mediterranean. Among many pests of bee colonies, Vespa orientalis was recorded to be one of the most destructive. OBJECTIVES: The aim of this study was to: (1) monitor the presence of pathogens carried by V. orientalis that could potentially threaten honey bees and public health; (2) describe the hornet's predatory behavior on honey bee colonies and (3) collect the medical history of a V. orientalis sting suffered by a 36-year-old woman. METHODS: Observations of V. orientalis predatory behavior and the catches of hornets for parasitological and microbiological examination, using molecular and bacteriological analyses, were carried out in three experimental apiaries, both in spring in order to capture the foundress queens and during the summer to capture the workers. Furthermore, the medical history and photographic documentation of a V. orientalis sting suffered by a 36-year-old woman have been collected. RESULTS: The results obtained highlight that V. orientalis is capable of causing serious damage to beekeeping by killing bees, putting under stress the honey bee colonies and by potentially spreading honey bee pathogens among apiaries. These hornets may also become a public health concern, since they are capable of inflicting multiple, painful stings on humans. CONCLUSIONS: Only the development of an Integrated Management Control Program will be able to contain the negative effects of anomalous population growth and the potentially negative impact on honey bees and public health of V. orientalis.

Lung Ultrasonography and Clinical Follow-Up Evaluations in Fattening Bulls Affected by Bovine Respiratory Disease (BRD) during the Restocking Period and after Tulathromycin and Ketoprofen Treatment.

Bovine respiratory disease (BRD) is a global infectious disease, causing decreased well-being and economic losses in livestock, frequently during the restocking period. The aim of this study was to evaluate the feasibility of thoracic ultrasonography (TUS) to assess BRD in restocked animals, and the effectiveness of tulathromycin and ketoprofen treatment in sick animals. A total of 60 Limousin fattening bulls were enrolled. On the day of restocking (T0), the animals were divided into two groups based on TUS assessment of six lung areas: group C (ultrasonography score (US score) < 3) and group D (US score ≥ 3). Group D received a single administration of tulathromycin and ketoprofen at T0: this group was revaluated after 1.5, 3, 7, and 14 days. Both groups were revaluated after 21 days. The two groups showed a significant difference both in US score and clinical symptoms (respiratory score, nasal and ocular discharges, and rectal temperature) at T0. In group D, the treatment was effective in improving the clinical symptoms and US score, particularly reducing the severity of lung lesions. TUS represents a non-invasive and cost-effective tool for BRD early diagnosis and for monitoring treatment efficacy in restocked livestock.

Short-term and long-term effects of antimicrobial use on antimicrobial resistance in broiler and turkey farms.

RESEARCH HIGHLIGHTSSulfamethoxazole and ampicillin resistance are the highest in E. coli isolates of both broilers and turkeys.Short-term effects of antibiotic use on resistance are seen more often than long-term effects.Historical penicillin use is associated with penicillin resistance in broilers.There is an association between historical use and resistance to trimethoprim in turkeys.

Business intelligence tools to optimize the appropriateness of the diagnostic process for clinical and epidemiologic purposes in a multicenter veterinary pathology service.

Laboratory tests provide essential support to the veterinary practitioner, and their use has grown exponentially. This growth is the result of several factors, such as the eradication of historical diseases, the occurrence of multifactorial diseases, and the obligation to control endemic and epidemic diseases. However, the introduction of novel techniques is counterbalanced by economic constraints, and the establishment of evidence- and consensus-based guidelines is essential to support the pathologist. Therefore, we developed standardized protocols, categorized by species, type of production, age, and syndrome at the Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), a multicenter institution for animal health and food safety. We have 72 protocols in use for livestock, poultry, and pets, categorized as, for example, "bovine enteric calf", "rabbit respiratory", "broiler articular". Each protocol consists of a panel of tests, divided into 'mandatory' and 'ancillary', to be selected by the pathologist in order to reach the final diagnosis. After autopsy, the case is categorized into a specific syndrome, subsequently referred to as a syndrome-specific panel of analyses. The activity of the laboratories is monitored through a web-based dynamic reporting system developed using a business intelligence product (QlikView) connected to the laboratory information management system (IZILAB). On a daily basis, reports become available at general, laboratory, and case levels, and are updated as needed. The reporting system highlights epidemiologic variations in the field and allows verification of compliance with the protocols within the organization. The diagnostic protocols are revised annually to increase system efficiency and to address stakeholder requests.

Infection Dynamics of Mycoplasma bovis and Other Respiratory Mycoplasmas in Newly Imported Bulls on Italian Fattening Farms.

Italian beef production is mainly based on a feedlot system where calves are housed with mixed aged cattle often in conditions favourable to bovine respiratory disease (BRD). In Veneto, an indoor system is also used for imported bulls around 300-350 kg. Mycoplasmas, in particular Mycoplasma bovis and Mycoplasma dispar, contribute to BRD in young calves, but their role in the disease in older cattle has not been investigated. In this study, ten heads of cattle were selected from each of the 24 groups kept in 13 different farms. Bulls were sampled by nasal swabbing at 0, 15, and 60 days after arrival for Mycoplasma isolation. Identification was carried out by 16S-rDNA PCR followed by denaturing gradient gel electrophoresis. M. bovis, M. dispar, and M. bovirhinis were identified, and prevalence was analysed by mixed-effects logistic regression models. This showed that most bulls arrived free of M. bovis, but within two weeks, approximately 40% became infected, decreasing to 13% by the last sampling. In contrast, the prevalence of M. dispar was not dependent on time or seasonality, while M. bovirhinis only showed a seasonality-dependent trend. The Italian fattening system creates an ideal environment for infection with M. bovis, probably originating from previously stabled animals.

Replication of Influenza D Viruses of Bovine and Swine Origin in Ovine Respiratory Explants and Their Attachment to the Respiratory Tract of Bovine, Sheep, Goat, Horse, and Swine.

Bovine is considered the main reservoir of influenza D virus (IDV), however, low levels of seropositivity in other farmed species suggest a wide range of potential hosts. Nevertheless, it is not clear whether this scenario is the result of rare spillover events upon contact with bovines, or a lack of adaptation of IDV to these hosts. Among these species, sheep represents a crucial component of the rural economy in many developing countries, but little is known about its role in the ecology of the disease. To evaluate the susceptibility of sheep to IDV viruses of different origin, we used ovine respiratory tissues as an ex vivo model and investigated the infective phenotype of two IDV strains isolated from either bovine (IDV-BOV) or swine (IDV-SW). For translatability purposes, we included a parainfluenza type 3 virus, as positive control, given its known respiratory tropism in sheep. We performed a timed evaluation of the viral infectivity, cell tropism and the associated histopathology, by means of tissue culture infectious dose assays on supernatants and histological/immunohistochemical analyses on explanted tissues, respectively. To further investigate differences in the phenotype of these two strains and to identify the potential targets of replication in the most commonly land-based farmed mammalian species, we carried out virus binding assays on histological sections of the respiratory tract of bovine, caprine, ovine, horse and swine. Our results demonstrated that IDV successfully replicates in nasal, tracheal and lung ovine tissues, suggesting a moderate susceptibility of this species to IDV infection. Interestingly, despite the high genetic identity of these strains, IDV- BOV consistently replicated to higher titers than IDV-SW in all respiratory tracts, suggesting IDV viruses might display considerable levels of variability in their phenotype when crossing the species barrier. Virus binding assays confirmed a superior affinity of the IDV viruses for the bovine upper respiratory tract, and a preference for the pharyngeal epithelium of small ruminants, indicating possible targets to improve the sensitivity of virological sampling for diagnostic and post-mortem purposes. Further pathogenesis and cross-species transmission studies will be necessary to elucidate the ecology of IDV and eventually allow the design of cost-effective surveillance strategies.

Genetic characterization of Neospora caninum from Northern Italian cattle reveals high diversity in European N. caninum populations.

Recent studies have revealed extensive genetic variations among Neospora caninum, a cyst-forming protozoan parasite that is one of the main causes of bovine abortion in the cattle industry worldwide. Previous genetic studies based on multilocus microsatellite genotyping (MLGs) of different Ibero-American populations showed a high genetic diversity. These studies provided clear clues of a predominant clonal propagation in cattle and population sub-structuring partially associated with geographical origin. Although, these reports were limited to a reduced number of countries. In this study, the N. caninum isolates from aborted bovine fetuses and stillbirths and a goat abortion from Northern Italy were investigated genetically using 9 microsatellite markers. Complete or nearly complete isolate profiles were obtained from 30 fetuses and stillbirths. An extensive genetic diversity was also found in this Italian N. caninum population. The study of genetic relationships among Italian MLGs using network (eBURST) and principal component analyses based on the allele-sharing coefficient (PCoA) showed different clonal subpopulations disseminated throughout Northern Italy without apparent segregation depending on the geographic origin, cattle breed, or time of collection. The presence of linkage disequilibrium supports a predominant clonal propagation of Italian N. caninum. In addition, most of Italian MLGs segregated from other global populations including Spain, Argentina, Mexico, Brazil, Germany, and Scotland, suggesting the existence of specific N. caninum subpopulations in the Northern Italy and different subpopulations of N. caninum circulating in Europe.

The Effects of Decreasing Dietary Crude Protein on the Growth Performance, Feed Efficiency and Meat Quality of Finishing Charolais Bulls.

This study aimed to evaluate the effect of decreasing dietary crude protein (CP) on the performance of finishing Charolais bulls in the Italian rearing system. Animals were fed two diets, differing only in the CP level (low protein (LP), 13.5% CP versus control (CON), 15.0% CP). Dry matter (DM) intake (DMI) and animals' weights were recorded to obtain average daily gain (ADG) and feed conversion rate (FCR). Feed and fecal samples were collected to evaluate digestibility of diet components. Daily cost of the ration (DRC), feed cost per kg of daily weight gain (CDG) and daily gross margin (DGM) were calculated to analyze the possible benefits of decreasing the protein level. Meat quality analyses were also conducted. Higher DMI (10.6 versus 10 kg/d; p < 0.05) and ADG (1.47 versus 1.36 kg/d; p < 0.05) were observed for CON. No differences in FCR or digestibility were found. Even if the DRC was lower (p < 0.05) for the LP diet (2.26 versus 1.97 €; CON versus LP), no difference was reported for CDG and DGM. Meat lightness and redness were significantly lower and higher in the LP, respectively. To conclude, the CP requirement in these rearing conditions appeared to be higher than 13.5%.

First whole genome characterization of porcine astrovirus detected in swine faeces in Italy.

Porcine astroviruses (PoAstV) are found in the gastrointestinal tract of healthy and diseased pigs worldwide. However, their role in causing enteric disease in pigs and other animals has not been elucidated. In the present report, we describe for the first time in Italy, the identification and genetic characterization, through whole genome sequencing, of a PoAstV2 in pigs in Northeast Italy in 2015. This instance is the first detection of PoAstV2 in pigs in Italy. The phylogenetic analysis of the complete ORF2 segment highlights the high similarity of this virus to those circulating that same year in Japan. There are very few full astrovirus genomes available, and the present data represent an important contribution towards a better understanding of the characteristics and evolution of these viruses.

Mycobacterium caprae in a dairy farm in Northeast Italy.

Veneto region, Northeast Italy, has been declared officially free from bovine tuberculosis since 2008, although the disease is sporadically detected in association with cattle trade. In September 2015, bovine tuberculosis was detected in a dairy cattle farm of the region, in a holding with 69 animals. The herd underwent single intradermal tuberculin testing as part of the regional surveillance plan, and 24 animals resulted positive. Mycobacterium caprae was evidenced in 22 samples, further genotyped by PCR-based assays, as Allgäu type. Epidemiological investigation reported that sixteen animals were introduced from an officially tuberculosis free Member State in previous years. Nevertheless, spoligotyping and multilocus variable tandem repeat analysis (MLVA) indicated that M. caprae was strictly related to the strain circulating in 2007-2009 in Trento province, although no at-risk contacts were described. M. caprae is a zoonotic pathogen and further analyses are warranted in order to control its spread and impact on public health and animal trade.

Identification and genetic characterization of bovine enterovirus by combination of two next generation sequencing platforms.

Prompt and accurate diagnosis is warranted for infectious diseases of domestic animals which may have a significant impact on animal production or clinical practice. In this study, the identification and genetic characterization of a bovine enterovirus (BEV) strain isolated from a calf with diarrhea, are described. Two different next generation sequencing platforms were employed. Shotgun metagenomic accomplished by MinION sequencing (Oxford Nanopore Technologies) allowed the identification of BEV RNA from a cell-culture isolate. BEV was then confirmed by a specific real time RT-PCR assay. To achieve the whole genome of this isolate, sequence reads obtained by MinION were coupled with those originating from NextSeq500 (Illumina). Genomic relatedness and phylogeny with extant BEV strains is also reported. Overall, this manuscript highlights the use of the portable MinION sequence technology as a tool for support diagnostics in veterinary practice.

Use of rumination and activity data as health status and performance indicators in beef cattle during the early fattening period.

The aim of this study was to measure the level of activity and rumination in young bulls and to assess whether these data can be used as indicators of health status and average daily weight gain (ADG). Two groups of animals (period 1: n=108 animals; period 2: n=106 animals) were fitted with sensors to measure daily activity and rumination, were weighed on arrival and at the end of the trial (70 days) and were checked twice daily to verify their health condition. Any clinical signs and therapies were recorded. The dishomogeneity index of rumination (DR), and the daily dishomogeneity indices of activity (DDA) and rumination (DDR), were calculated. Bulls had an ADG of 1.42±0.38kg/day and showed an average duration of daily rumination of 404±63min and an average activity of 474±46 bits, respectively. Animals characterised by low ADG had lower values of minimum daily rumination (P=0.01) and DDA (P<0.001), and a greater rumination range (P=0.007) and DR (P=0.003). Bovine respiratory disease and lameness were detected 31 and five times, respectively; among affected animals, the average daily activity, rumination and DDA were lower (P<0.05) at 3-6days before the onset of visible clinical signs, whereas DDR increased compared to the values when individuals were apparently healthy. The use of individual sensors appears promising for the early diagnosis of disease in beef cattle and for improving herd management.

Continuous straw provision reduces prevalence of oesophago-gastric ulcer in pigs slaughtered at 170 kg (heavy pigs).

Adopting a 2 × 2 × 2 factorial design, this study evaluated whether continuous straw provision by racks, tail docking and gender (barrows vs. females) have an effect on the prevalence of lung lesions and oesophago-gastric ulcer (OGU) visually scored at slaughter in 635 Italian heavy pigs (169 ± 4 kg). The lung lesions were very low (72% of pigs with score 0), and were not significantly different among the experimental groups. Overall, OGU was diagnosed in 47% of the pigs. The consumption of small amounts of straw (70 g/day/pig) represented a protective factor against the onset of OGU (OR: 0.27). Barrows were more likely than females to have OGU (OR: 1.52), while no significant differences between docked and undocked pigs were detected. Nevertheless, the presence of straw acted as a protective factor particularly in undocked pigs (OR: 0.16), suggesting that in this group the absence of rooting material may have a stronger effect on welfare.

Tail docking and the rearing of heavy pigs: the role played by gender and the presence of straw in the control of tail biting. Blood parameters, behaviour and skin lesions.

This study evaluated whether the specific heavy pig rearing context allowed the fattening of undocked pigs without an outbreak of tail biting. At the same time, gender and straw availability (small amounts) were considered to understand their possible interactions with tail presence in the display of tail biting. A 2 × 2 × 2 factorial design was adopted to test the effects of these factors on blood parameters, behaviour and tail/ear lesions. Few interactions among factors were detected. Undocked pigs showed lower cortisol (P<0.02), lying behaviour (P<0.001), and higher risk of tail/ear biting (weeks 3 and 9), but lower risk of tail lesions (week 14). Straw increased the motivation for exploring (P<0.001), reduced serum haptoglobin (P<0.001) and the risk for tail biting (weeks 3, 9, 18) and ear biting (weeks 3, 9). Results highlight the importance of straw as an environmental enrichment and seem to indicate that fattening undocked heavy pigs is possible.

Genetic characterization of a new astrovirus detected in dogs suffering from diarrhoea.

Astroviruses have been described in several animals species frequently associated with diarrhoea, especially in young animals. In dogs, astrovirus-like particles have been observed sporadically and very little is known about their epidemiology and characteristics. In this paper, we describe the detection of astrovirus-like particles in symptomatic puppies. Furthermore, for the first time in this species, the presumptive identification made by electron microscopy was confirmed by genetic analysis of the viral RNA conducted directly on the clinical specimens. Genetic sequences of ORF2 (2443 nt), encoding for the capsid protein, and partial sequence of ORF1b (346 nt), encoding for the viral polymerase, identified the viruses as member of the family Astroviridae. The phylogenetic analysis clearly clustered canine astroviruses in the genus Mamastrovirus. Relative closest similarities were revealed with a cluster comprising human, porcine and feline astroviruses, based on the ORF2 sequences available. Based on the species definition for astroviruses and on the data obtained in this study, we suggest a new species of astrovirus - canine astrovirus, CaAstV - to be included in the genus Mamastrovirus.