Papers by Mariagrazia Zanoni
Frontiers in Veterinary Science, Sep 13, 2021
The European wild boar (WB) (Sus scrofa) population has rapidly expanded over the years, raising ... more The European wild boar (WB) (Sus scrofa) population has rapidly expanded over the years, raising public health concerns over the species reservoir of several pathogens, including Mycobacterium microti (Mm), a Mycobacterium tuberculosis complex member. In this study, we aimed to investigate the Mm natural infection in WB in Lombardy and Emilia Romagna Italian regions by statistically evaluating the granulomatous lesions' histological features and Mm microbiological isolation. We analyzed 103 WB retropharyngeal and submandibular lymph nodes (LNs) for Mm identified by gyrB PCR-restriction fragment length polymorphism, and were retrospectively selected and histologically assessed. For each sample, Hematoxylin-eosin and Ziehl-Neelsen stained slides were evaluated. Considered histological variables were: the number of granulomas, size and maturational stage of granulomas, granulomas completeness within the section, number of multinucleated giant macrophages (MGMs), and acid-fast (AF) bacilli per granuloma. Furthermore, Mm microbiological results were also considered. Mm microbiological isolation was negatively influenced by granulomas maturation and positively affected by AF bacilli's presence within the section. Granuloma maturation was positively influenced by granuloma size and granuloma incompleteness and negatively affected by the number of granulomas in the section and the number of MGMs within the granuloma. The results indicate that granuloma maturation should ensures an efficient containment of Mm infection in the WB, suggesting that the intra-species transmission of the disease might be an unlikely event.
Veterinaria Italiana, Jul 14, 2020
Mycobacterium avium infection was diagnosed in an adult cat showing acute lameness of the right h... more Mycobacterium avium infection was diagnosed in an adult cat showing acute lameness of the right hind limb, enlargement of the right popliteal lymph node and two cutaneous nodular lesions of the right chest wall. Conventional radiography of the proximal tibia showed a proliferative osteolytic lesion. Cytological examination of the right popliteal lymph node and the nodular skin lesions fine needle aspiration smears, demonstrated granulomatous inflammation with many negative staining bacilli within macrophages or in smears background. The diagnosis was confirmed by Ziehl‑Neelsen staining of the smears and the identification of mycobacteria was performed by microbiological and molecular methods. Histopathology performed after the necropsy revealed disseminated mycobacteriosis with granulomatous mesenteric lymphadenitis, granulomatous pneumonia, hepatitis and tibial osteomyelitis. M. avium is a well‑known agent of gastro‑enteric, respiratory or disseminated disease in immunocompromised cats but there are few cases reported in literature of bone involvement in systemic mycobacteriosis.
Hystrix-italian Journal of Mammalogy, Dec 7, 2017
Brown hares have undergone a substantial population decline in Europe during recent decades, caus... more Brown hares have undergone a substantial population decline in Europe during recent decades, caused by, among other factors, the occurrence of European Brown Hare Syndrome (EBHS). To improve our knowledge regarding EBHS epidemiology, we developed a mathematical model that takes into consideration both brown hare biology and the infection dynamics of the EBHS virus (EBHSV). The model consists of eight ordinary differential equations simulating the spread of the virus in a closed hare population. Simulations showed that EBHSV's transmission has complex dynamics, which are strongly affected by the hare density. In particular, a density threshold of 7 individuals/km 2 was identified, determining two opposite epidemiological patterns: the extinction of the EBHSV below the threshold and its endemic stability when the hare population density is above the threshold, with a seroprevalence proportional to the population density. The model was validated using serological data collected in different areas in the province of Brescia (Northern Italy). The results suggested that the maintenance of the endemic circulating viral level through density control mechanisms is the best strategy for reducing EBHS's impact.
Journal of Clinical Microbiology, May 28, 2014
Approximately 23,000 hunter-harvested wild boars from the pre-Alpine area of northern Italy were ... more Approximately 23,000 hunter-harvested wild boars from the pre-Alpine area of northern Italy were examined for tuberculosis over a 9-year period (2003 to 2011). Retropharyngeal and mandibular lymph nodes from the wild boars were examined grossly, and 1,151 of the lymph nodes were analyzed in our laboratory by histology (728 samples) and culture isolation (819 samples). Mycobacterium tuberculosis complex (MTBC)-specific PCR (1,142 samples) was used for molecular-level detection in tissue samples, as was a gyrB restriction fragment length polymorphism (RFLP) assay (322 samples). Lesions compatible with tuberculosis and indistinguishable from those described in cases of Mycobacterium bovis infection had been observed since 2003. Mycobacterium microti was identified directly in 256 tissue samples by the adopted molecular approaches. However, only 26 M. microti strains were obtained by culture isolation due to the well-known difficulties in isolating this slow-growing mycobacterium. During 2006, a prevalence study was performed in two provinces of the area, and the diffusion of M. microti was calculated to be 5.8% (95% confidence intervals surrounding the estimated prevalences [CI P95% ], 3.94 to 7.68%). Over the following years (2007 to 2011), the presence of M. microti appeared to be stable. All isolates were genotyped by spoligotyping and exact tandem repeat analysis (ETR types A to F). In addition to the typical vole type (SB0118), a new spoligotype lacking the 43 spacers was found. Spoligotyping was also applied directly to tissue samples, and a geographical cluster distribution of the two spoligotypes was observed. This is the first report studying the diffusion and genetic variability of M. microti in wild boar.
International Journal of Infectious Diseases, Dec 1, 2016
were as follows: ST6 (n=4, WCP), ST1 (n=2, WCP), ST876 (n=2, WCP), ST54 (n=1, WCP), ST3 (n=1, GP)... more were as follows: ST6 (n=4, WCP), ST1 (n=2, WCP), ST876 (n=2, WCP), ST54 (n=1, WCP), ST3 (n=1, GP), ST820 (n=1, ECP). In particular, our largest group was associated with MLST subtype ST6, a subtype commonly associated with unfavourable outcomes in patients. Conclusion: Analysis of WGS data using bioinformatics tools and on-line analysis pipelines at the CGE provided a single, rapid and cost-effective approach to investigate the molecular epidemiology of L. monocytogenes. This study has initiated a larger surveillance project for L. monocytogenes in South Africa. In future, all South African L. monocytogenes isolates will routinely be investigated using WGS.
Research in Veterinary Science, Oct 1, 2013
A tuberculosis (TB) outbreak caused by Mycobacterium bovis occurred in a mixed herd of three catt... more A tuberculosis (TB) outbreak caused by Mycobacterium bovis occurred in a mixed herd of three cattle and eighteen goats in Northern Italy in 2005. All the cattle were removed, as opposed to the co-existing goats, who remained in the farm and were not subsequently tested by the official intradermal tuberculin test. At the beginning of May 2006, a 7-day old calf was introduced into the herd from an officially TB-free (OTF) farm. On October 2006, tuberculous lesions were detected at the slaughterhouse in the same animal. The following epidemiological investigation on the herd highlighted a clinical suspicion of TB in one goat out of 35, and visible lesions were found at necropsy in the respiratory and intestinal tracts. Bacteriological culture and molecular tests confirmed the presence of M. bovis in both animals. Spoligotyping and Mycobacterial Interspersed Repetitive Units - Variable Number of Tandem Repeats (MIRU-VNTR) showed the same genomic profile of the previous breakdown occurred in 2005. Since this profile has never been described in Italy, these findings suggest the probable transmission of TB within the farm among cattle and goats. The remaining 34 goats were also tested by single intradermal cervical comparative tuberculin (SICCT) test, Interferon (IFN)-γ assay and ELISA for antibody to M. bovis. The SICCT test and the IFN-γ showed a good concordance with 20 and 19 positive reactors, respectively. By ELISA we found 12Ab-positive animals, seven of which had not been detected by the tests for cell-mediated immunity. Finally, 15 goats were found positive for gross lesions at necropsy. The in vivo tests revealed a total of 27 positive animals out of 35, which highlights the usefulness of the serology in parallel with SICCT and IFN-γ when an advanced stage of infection is suspected. Moreover, our results confirm the necessity for adopting the official tuberculin test on goats co-existing with cattle.
PubMed, Dec 31, 2019
Veneto region, Northeast Italy, has been declared officially free from bovine tuberculosis since ... more 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.
Hystrix-italian Journal of Mammalogy, Nov 14, 2016
Wild boar (Sus scrofa) is considered a potential source of several viral and bacterial pathogens ... more Wild boar (Sus scrofa) is considered a potential source of several viral and bacterial pathogens that represent a risk to humans and other mammals. Among these the spirochete of the genus Leptospira causes Leptospirosis, a neglected zoonotic disease. This study investigates the presence of antibodies against pathogenic Leptospira spp. serovars in wild boar in different areas of the Lombardy region (Northern Italy) and the risk factors associated with its presence in a specific population. Blood and tissue samples from wild boars were collected from 2008 to 2013 during a wildlife survey. A total of 2101 serum samples were analysed using a Microscopic Agglutination Test to detect antibodies against Leptospira interrogans sensu lato. Culture isolation and Leptospira DNA detection by PCR were carried out using 244 kidney and 245 urine samples, respectively. Antibodies against 5 serovars were detected in 321 serum samples (15.3%). Bratislava was the most frequently identified serovar (14.6%; 95% C.I. 13.1-16.2%), followed by Copenhageni (1.48%; 95% C.I. 1.0-2.1%), Grippotyphosa and Pomona (0.48%; 95% C.I. 0.23-0.87%), and Canicola (0.05%; 95% C.I. 0-0.3%). Genotyping by Multilocus Sequence Typing and Multilocus Variable number tandem repeat Analysis of a single leptospire isolate confirmed the presence of L. interrogans serovar Bratislava with the same genetic profile as Jez Bratislava. The statistical analyses confirmed the wild boar's age class as an important risk factor for the seroprevalence of leptospirosis, whereas no effect of wild boar abundance on seroprevalence was observed. In addition, an increasing seroprevalence was observed, in particular that of Australis Bratislava showed a general increasing pattern over the years. Our results confirmed that wild boars are a potential source of pathogenic Leptospira spp., which can infect humans, domestic animals and other wild animal species in low-density regions, such as those on the Alps.
... Alternative Title, Piano di controllo della rinotracheite bovina infettiva in regione Lombard... more ... Alternative Title, Piano di controllo della rinotracheite bovina infettiva in regione Lombardia: risultati preliminari in provincia di Brescia [Lombardia]. Conference, [Italian Association for Buiatrics. Annual meeting], Teramo (Italy), 5-6-7 May 2005. Date of publication, 2005. ...
Italian Journal of Food Safety, Apr 6, 2020
Bovine tuberculosis (bTB) is a contagious chronic disease associated with progressive emaciation ... more Bovine tuberculosis (bTB) is a contagious chronic disease associated with progressive emaciation (starvation) and tubercles (granuloma) formation commonly caused by Mycobacterium bovis. In cattle, M. caprae may also be responsible for bTB. In EU, human tuberculosis due to M. bovis had a notification rate of 0.04 cases per 100,000 inhabitants in 2017, but data did not include M. caprae infections. From September 2018 to April 2019, bTB outbreaks were investigated in three neighbouring dairy cattle herds in Parma province, Northern Italy. Parma municipality belongs to an officially free of bovine tuberculosis (OTF) Italian region. Official testing on cattle herds, performed every three years as legally required, revealed no positive animals. Tubercular lesions were found during the post mortem (PM) examination of slaughtered cattle and M. caprae genotype SB0418/VNTR 4,3,5,3,4,5,2,2,4, 3,15,5 was isolated. This report confirms the crucial importance of PM veterinary inspection at slaughterhouse, despite the OTF status of cattle herds.
Research in Veterinary Science, Aug 1, 2015
The key component of most European pig Salmonella control programmes is the classification of her... more The key component of most European pig Salmonella control programmes is the classification of herds according to seroprevalence at slaughter. The objectives of this study were to estimate the true Salmonella seroprevalence, and investigate the association between the true status of infection and serology in slaughter heavy pigs. Blood of 3340 pigs was collected and tested with ELISA. From 385 pigs, also lymph nodes and cecal content were collected for bacteriology. Analysis was performed in a Bayesian framework. Results showed that a large proportion of pigs was serologically positive (herd seroprevalence 93% and within-herd seroprevalence higher than 81% in half of herds at cut-off 10 OD%). The association between the true status of infection and serology was not significant, and therefore the classification of heavy pig herds according to seroprevalence at slaughter would not be suitable to reduce the risk of introducing Salmonella into the food chain.
Acta Veterinaria Scandinavica, Dec 1, 2014
Background: Salmonella spp. have been isolated from a wide range of wild animals. Opportunistic w... more Background: Salmonella spp. have been isolated from a wide range of wild animals. Opportunistic wild carnivores such as red foxes (Vulpes vulpes) and badgers (Meles meles) may act as environmental indicators or as potential sources of salmonellosis in humans. The present study characterizes Salmonella spp. isolated from the intestinal contents of hunted or dead red foxes (n = 509) and badgers (n = 17) in northern Italy. Findings: Thirty-one strains of Salmonella belonging to 3 Salmonella enterica subspecies were isolated. Fourteen different serovars of S. enterica subsp. enterica were identified, among which were serovars often associated with human illness. Conclusions: Wild opportunistic predators can influence the probability of infection of both domestic animals and humans through active shedding of the pathogen to the environment. The epidemiological role of wild carnivores in the spread of salmonellosis needs to be further studied.
Journal of Dairy Science, Mar 1, 2009
An outbreak of clinical mastitis was observed in dairy goats due to the zoonotic pathogen Strepto... more An outbreak of clinical mastitis was observed in dairy goats due to the zoonotic pathogen Streptococcus equi ssp. zooepidemicus. Affected goats were culled to prevent transmission of infection to other animals or humans. The objective of the study was to determine whether horses on the same farm were the source of the pathogen. Streptococcus equi ssp. zooepidemicus was obtained from milk of 10% of goats in the herd and from feces of 3 of 7 healthy horses that shared pasture and housing with the goats. Isolates of caprine and equine origin had identical biochemical profiles, including the ability to ferment sorbitol and lactose, which distinguishes S. equi ssp. zooepidemicus from S. equi ssp. equi. Sequencing of the 16S-23S intergenic spacer region and results from sodA-seeI multiplex PCR supported identification of isolates as S. equi ssp. zooepidemicus. Based on random amplified polymorphic DNA typing and rpoB and sodA sequencing, caprine isolates were indistinguishable from each other, but distinct from equine isolates. Further analysis of equine fecal samples showed that multiple strains of S. equi ssp. zooepidemicus can be present in a single sample or in sequential samples obtained from a single horse. Failure to detect the mastitis-causing strain in equine feces may indicate that horses were not the source of the mastitis outbreak in goats. Alternatively, the outbreak may be due to presence of multiple S. equi ssp. zooepidemicus strains in equine feces and a failure to detect all strains when analyzing a limited number of isolates per sample.
European Journal of Wildlife Research, Sep 22, 2013
Mycoplasma hyopneumoniae (Mhyo) is the principal etiological agent of enzootic pneumonia (EP), on... more Mycoplasma hyopneumoniae (Mhyo) is the principal etiological agent of enzootic pneumonia (EP), one of the most economically important diseases in the pig production industry worldwide. Although swine and wild boars (Sus scrofa) share susceptibility to Mhyo infection, information regarding the dynamics of Mhyo infections and pathology in wild boars is currently limited. Therefore, the aim of this study was to determine the spatiotemporal dynamics of Mhyo infections in free-living wild boars through serological ELISA testing. Additionally, the presence of EP-like gross lesions and their association with the presence of Mhyo, based on a PCR assay, were assessed. Over a period of 5 years, antibodies against Mhyo were detected in 655 (30.0 %) of the 2,177 analyzed wild boars. A generalized temporal increase of seroprevalence coupled with an increase of mean antibody titers of seropositive individuals was found. Moreover, a similar seroprevalence between age classes associated with higher antibody titers of younger individuals indicated the wild boars were infected during the early stages of their life. Out of 99 lungs tested, 43 showed EP-like lesions and 45 were PCR positive for the presence of Mhyo DNA. The lung lesion scores were related to the sex and age of the wild boars, with young individuals having higher lung scores than others, and there was a positive association with the Mhyo PCR-positive status. The temporal increase of the Mhyo seroprevalence and infection association with EP-like lesions, when coupled with the spreading of wild boar populations, raises concerns on the epidemiological role of this species. Keywords Mycoplasma hyopneumoniae. Wild boar. Enzootic pneumonia. Italy the caudal lobes of the lungs (Ross 1999). Information about Mhyo prevalence, infection, and macroscopic lesions in wild boars is currently limited. The seroprevalence of antibodies against Mhyo in wild boars ranged from 21 % in
European Journal of Wildlife Research, Sep 20, 2014
The progressive decline in the hare population across Europe has been associated with the occurre... more The progressive decline in the hare population across Europe has been associated with the occurrence of European brown hare syndrome (EBHS), a highly contagious disease considered endemic in all European countries. This study aimed to evaluate the in-field temporal dynamics of European brown hare syndrome virus (EBHSV) infection in wild European brown hares (Lepus europaeus) and to test the influence of population density on EBHS seroprevalence. A total of 512 blood samples were collected from free ranging hares captured for restocking in seven different areas of the province of Brescia (Northern Italy) during seven consecutive years (2006-2013) and tested using a competitive ELISA. A generalized linear mixed model estimated the yearly effects of population density on EBHS prevalence. Of the 512 tested, 344 (67.2 %) tested positive for EBHSV antibodies, with the annual seroprevalence ranging from 94.3 to 35.8 %. The prevalence was 3.303 times higher in areas with a density of over 15 hares/km 2 and declined over the years. The results indicate the ongoing transmission of the virus in the tested brown hare population. Since the eradication of EBHS in a wild population is not feasible, a strategy aimed at promoting the endemic stability of the virus through density-dependent mechanisms could be applied; however, this seems more difficult in practice than in theory and would most likely require a very high density of brown hares.
Transboundary and Emerging Diseases, Jan 12, 2015
Mycobacterium microti has recently been described as the causative agent of tuberculosis-like les... more Mycobacterium microti has recently been described as the causative agent of tuberculosis-like lesions in wild boar (Sus scrofa), a reservoir specie of Mycobacterium tuberculosis complex (MTBC) in some European Mediterranean ecosystem. Through a five-year survey on tuberculosis in free-living wild boars, the epidemiological trend of M. microti infections and the host and population risk factors linked with its occurrence were described. Retropharyngeal and mandibular lymph nodes of 3041 hunted wild boars from six different districts were macroscopically inspected. The sex and age of each animal were registered, as well as the animal abundance in each district. Lesions compatible with tuberculosis (190) were collected and analysed using a gyrB PCR-RFLP assay. M. microti was identified directly in 99 tissue samples (Prev = 3.26%; 95% CI: 2.67-3.97%), while neither Mycobacterium bovis, nor other members of the MTBC were detected. The probability of being M. microti positive showed spatio-temporal variability, with 26% of increase of risk of being infected for each year. Moreover, a positive effect of wild boar abundance and age on the prevalence was detected. The generalized increase in the European wild boar population, coupled with its sensitivity to M. microti infection, poses a future concern for the identification and management of MTBC members in wild boar.
Ecohealth, Sep 21, 2015
Although wild boar can act as a persistent Aujeszky's disease (AD) reservoir, limited data are av... more Although wild boar can act as a persistent Aujeszky's disease (AD) reservoir, limited data are available on long-term epidemiology in free-ranging wild boar living in areas where industrial swine herds are limited. Hence, this study provides crucial information, which fills this knowledge gap, on the natural dynamics of AD infection. From 3260 sera sampled during eight hunting seasons, 162 (4.97%) were tested positive. Factors, including the animal's age class, and the sampling year, had significant effects on the probability of the wild boar being seropositive, while wild boar mean abundance per area, yearly abundance and the total number of pig farms, as well as interactions among age, year and sex, were not significant. In particular, a positive trend of seroprevalence was observed over the years, with values ranging from 2.1 to 10.8%. This long-term surveillance showed an increase in seroprevalence with a higher probability of being seropositive in older individuals and the independence of wild boar seropositivity from the likelihood of contact with pigs in the area.
Foods, Oct 12, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Transboundary and Emerging Diseases, May 10, 2015
In 2013, the circulation of West Nile virus (WNV) was detected in the Lombardy region and the fol... more In 2013, the circulation of West Nile virus (WNV) was detected in the Lombardy region and the following year a surveillance programme was activated with the aim of early identification of the viral distribution in mosquitoes and wild birds. A total of 50 959 Culex spp. mosquitoes grouped in six hundred and forty-seven pools as well as 1400 birds were screened by RT-PCR for the presence of West Nile virus leading to the identification of the viral genome in 32 mosquito pools and 13 wild birds. The surveillance was able to detect the WNV circulation on an average of 42 days (CI 95% 29.98-53.86; Student's t-distribution) before the occurrence of human West Nile disease (WND) cases in the same area. These results demonstrate the presence of WNV in the Lombardy region and confirm entomological and wild birds surveillance as an effective measure for the early identification of WNV circulation in infected areas, thus providing a useful and cost-effective tool for the public health authorities in the application of measures to prevent human infection.
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Papers by Mariagrazia Zanoni