The Mycobacterium avium complex - an underestimated threat to humans and animals

INTRODUCTION AND OBJECTIVE

The Mycobacterium avium complex (MAC) is a group of acid-resistant bacteria within the Mycobacteriaceae. Their cell walls have a specific structure impervious to many disinfectants. Mycobacteria are widespread in the environment and can also be found in food. This aim of the article is to review the current state of knowledge about the sources of infection, symptoms and treatment of MAC diseases in humans and animals, and summarizes the available methods for identifying the bacteria. It pays a special attention to the zoonotic potential of MAC bacteria and possible routes of transmission between humans and animals, including possible food-borne routes.

BRIEF DESCRIPTION OF THE STATE OF KNOWLEDGE.

MAC bacterial infections occur both in immunocompetent people and those with functional predispositions and compromised immunity, particularly during HIV infection or immunosuppressive treatment. The incidence of MAC infections in humans is growing, with the most common form of infection being pulmonary disease (MTC-PD); however, there are conflicting reports on the role of Mycobacterium avium paratuberculosis (MAP) in the development of Crohn's disease. MAC bacteria can also attack livestock, household pets, and wild animals. Unfortunately, treatment is lengthy and often fails due to microbiological relapse; there is also increasing evidence of MAC bacteria are developing multi-drug resistance.

CONCLUSIONS

Although new antibiotics are being created to inhibit the growth and division of Mycobacterium avium, there is clearly a need for further research into the virulence factors associated with MAC bacteria. Further studies should also examine the role of MAP in the etiopathogenesis of Crohn's disease.

Mixed Infection of Mycobacterium szulgai, M. lentiflavum, and Gram-Negative Bacteria as a Cause of Death in a Brown Caiman Caiman crocodylus: A Case Report

This paper describes a fatal case of nontuberculosis mycobacteriosis in a four-year-old brown caiman kept in captivity. Although the clinical signs were asymptomatic, severe gross lesions were observed, namely necrotic inflammation of the intestines and granulomatous hepatitis. Microbiological and histopathological examination performed on the tissues collected postmortem revealed a mixed infection of Mycobacterium lentiflavum and Mycobacterium szulgai, secondarily mimicked with Salmonella Coeln, Aeromonas hydrofila, Citrobacter freundii, and Providencia rettgeri. Those microorganisms are not only potentially pathogenic to reptiles, but also have a zoonotic importance for humans. Our findings clearly demonstrate the importance of educating owners and maintaining hygiene rules when handling reptiles.

A serological survey of Toxoplasma gondii in polish pigs from organic farms, other housing systems and in pigs of different age groups

Background

The consumption of raw or undercooked meat, especially pork, and offal containing infective tissue cysts is suspected to be a significant route of infection with Toxoplasma gondii. Although the use of “animal-friendly pig production systems” ensuring direct contact with the natural environment offers ethical benefits, it limits the ability to ensure animal health; it may also increase the probability of infections by pathogens such as T. gondii, and thus their entry into the food chain. This study determines the seroprevalence of T. gondii in pigs from different housing systems and farms with different hygiene standards in Poland, as well as among pigs of different age groups from farms with high hygiene standards. In total 760 pig serum samples were examined for the presence of specific antibodies using the PrioCHECK^® Toxoplasma Ab porcine commercial ELISA test (Prionics, Switzerland).

Results

Test results with PP ≥ 20% were regarded as positive, as indicated by the manufacturer. Antibodies to T. gondii were found in 193 of 760 (25.4%) tested sera. Regarding different housing systems, antibodies were found in 117 pigs: of these, 52.6% (61/116) were from organic farms, 40.9% (47/115) from farms with low hygiene standards, 5.4% (9/167) from farms with high hygiene standards and 0% (0/40) from a farm with a high level of biosecurity. Regarding age groups, antibodies were found in 76 animals on farms with high hygiene standards: 11.1% (7/63) were pigs younger than 3 months, 0% (0/60) aged 3–4 months, 12.3% (7/57) aged 5–6 months (final fattening stage) and 43.7% (62/142) were sows aged 9 months and older.

Conclusions

Antibodies to T. gondii were most often found in pigs from organic and low-hygiene farms, as well as in pigs aged 9 months and older. Meat derived from seropositive animals can pose a potential source of infection for humans. As maternal antibodies to T. gondii can be present in the blood of piglets aged up to 3–4 months, serological examination is unjustified in piglets up to this age.

Microbiological and molecular monitoring for bovine tuberculosis in the Polish population of European bison (Bison bonasus)

INTRODUCTION AND OBJECTIVE

In recent years, bovine tuberculosis (BTB) has become one of the major health hazards facing the European bison (EB, Bison bonasus), a vulnerable species that requires active protection, including regular and effective health monitoring. Monitoring of zoonotic disease in wildlife is also an important part of public health protection. The aim of the study was to determine whether BTB still influences the EB population in Poland.

MATERIAL AND METHODS

During 2017-2019, mandibular, retropharyngeal and mediastinal lymph nodes were collected from 90 EB during post-mortem examination, and then cultivated on Lowenstein-Jensen and Stonebrink media. Isolated strains were subjected to molecular analysis to determine the species, spoligotype and MIRU-VNTR pattern.

RESULTS

Lesions were found in lymph nodes originating from eight EB (8.89%). Positive microbiological cultures for mycobacteria were obtained in samples from six (6.67%) EB. The isolated strains were identified as Mycobacterium caprae (material from four EB) and atypical mycobacteria (material from two EB). For M. caprae strains spoligotype M. bovis 4_CA 1600 was identified and the MIRU-VNTR pattern was identified as 345751355413232.

CONCLUSIONS

It is recommended that this potentially dangerous disease should be monitored in EB via a comprehensive strategy based on a combination of microbiological and molecular methods. Such monitoring will protect the health of both animals and humans.

Pathogens with potential impact on reproduction in captive and free-ranging European bison (Bison bonasus) in Poland - a serological survey

BACKGROUND

The European bison is an endangered species, and as such it is extremely important to monitor herds for pathogens which can lead to reproductive failure. The aim of the present study was to determine the current prevalence of antibodies to pathogens known to potentially influence reproduction in European bison. Serum samples from 183 bison, originating from different parts of Poland, were tested using commercial ELISA tests for antibodies to Chlamydia spp., Coxiella burnetti, Leptospira interrogans, Neospora caninum and Toxoplasma gondii; the findings were compared between captive and main free-ranging herds, and with regard to the influence of demographic factors such as age and sex. The prevalence of seropositivity was also checked with regard to location and the animal species sharing it.

RESULTS

Chlamydia spp. antibodies were present in 48 out of 130 (36.9%) tested samples. Coxiella burnetii was found in one sample out of 178 (0.58%). N. caninum in 36 out of 172 (20.9%) and T. gondii in 23 out of 172 (13.4%). No sample was positive for leptospirosis. Neither sex nor age appeared to have a significant effect on the occurrence of antibodies to the identified species. The prevalence of Chlamydia spp. in the samples varied significantly according to location; however, similar frequency ranges were observed between free ranging and captive herds. In contrast, antibodies to N. caninum were more common in free-ranging herds than captive herds, with the highest frequency observed in the Bieszczady Mountains.

CONCLUSIONS

Chlamydia spp., N. caninum and T. gondii might have a similar impact on the reproductive potential of European bison as they have on cattle. The high occurrence of antibodies to N. caninum in bison from the Bieszczady Mountains may be associated with the relatively high density of the wolf population in the area.

Citrobacter braakii Yield False-Positive Identification as Salmonella, a Note of Caution

BACKGROUND

Globally, Salmonella enterica is one of the leading causes of foodborne illness in humans. Food of animal origin is obligatorily tested for the presence of this pathogen. Unfortunately, in meat and meat products, this is often hampered by the presence of background microbiota, which may present as false-positive Salmonella.

METHODS

For the identification of Salmonella spp. from meat samples of beef, pork, and poultry, the authorized detection method is PN-EN ISO 6579-1:2017-04 with the White-Kauffmann-Le Minor scheme, two biochemical tests: API 20E and VITEK II, and a real-time PCR-based technique.

RESULTS

Out of 42 presumptive strains of Salmonella, 83.3% Salmonella enterica spp. enterica, 14.3% Citrobacter braakii, and 12.4% Proteus mirabilis were detected from 180 meat samples.

CONCLUSIONS

Presumptive strains of Salmonella should be identified based on genotypic properties such as DNA-based methods. The aim of this study was the isolation and identification of Salmonella spp. from miscellaneous meat sorts: beef, pork, and poultry.

The Risk of False-Positive Serological Results for Paratuberculosis in Mycobacterium bovis-Infected Cattle

Both bovine tuberculosis (BTB) and paratuberculosis (paraTB) continue to cause significant economic losses in cattle breeding; in addition, their etiological agents have zoonotic potential. Although the diagnostics of both diseases are still being improved, problems still remain, such as the potential for cross-reactivity to the antigens used in tests. The aim of the present study was to confirm whether animals known to harbor Mycobacterium bovis antibodies are at increased risk of yielding positive results in paraTB serotesting and, additionally, to verify the accuracy of three commonly used methods for confirming M. bovis infection: ELISA, the tuberculin skin test (TST), and the presence of gross lesions. Material was collected from 98 dairy cattle suspected of BTB due to TST-positive results. During postmortem examination, gross lesions were assessed visually. Blood, lymph nodes, and TB-suspected organs were collected. Serum was obtained from the collected blood and tested serologically for TB and paraTB. The tissues underwent standard microbiological testing for M. tuberculosis complex. Among the 98 TST-positive individuals, tuberculous gross lesions were detected in 57 (58.1%), MTBC were isolated in 83 (84.7%), and the ELISA test was positive for 21 (21.4%). None of the lesions characteristic for paraTB were detected. The chance of obtaining a positive TB result by ELISA was seven times higher using the ELISA-paraTB method; hence, there is a significant risk of obtaining false-positive serological results for paraTB in M. bovis-infected cattle. However, the hypothesis that infection of M. bovis or prior TST performance may have boosted the host immune response and therefore increased the sensitivity of the paraTB-ELISA cannot be excluded.

The European bison (Bison bonasus) as an indicatory species for the circulation of tick-borne encephalitis virus (TBEV) in natural foci in Poland

Tick-borne encephalitis (TBE) is one of the most common zoonotic diseases in Europe transmitted by Ixodidae vectors. While small mammals such as bank voles and ticks constitute the main reservoirs for virus transmission, large sylvatic species act as a food source for ticks. Cervids such as roe deer and red deer are considered sentinel species for TBE in natural foci. In addition, an increase of the population size and density of large wild mammals in an area corresponds to an increase in the tick burden and may potentially increase the prevalence of TBE virus (TBEV) in ticks and tick hosts and further exposure risk in humans. Humans are considered accidental hosts. The prevalence of TBE relies on interactions between host, vector and environment. The present study examines the exposure of the largest European herbivore, the European bison (Bison bonasus) to TBEV infection. Assessed using the IMMUNOZYM FSME ELISA (PROGEN), the overall TBEV seroprevalence was 62.7% in the 335 European bison that were studied. ELISA results were confirmed by the gold-standard virus neutralization test (VNT) with 98.7% sensitivity and thus giving a true prevalence of 63.5%. TBEV seroprevalence was significantly correlated to the origin, age group, sex, population type (free living/captive) and sanitary status (healthy/selectively eliminated/found dead/killed in accident) of the European bison in the univariable analysis. The highest seroprevalences were observed in the three largest north-eastern wild populations (Białowieska, Borecka and Knyszyńska forests), which corresponded with the highest incidence of human cases reported in the country. The risk of TBEV seropositivity increased with age and was higher in female and free-ranging European bison. Additionally, to the epidemiological investigation, the continuous detection of TBEV antibodies was studied by repetitive testing of animals over the course of 34 months. Two of six seropositive animals remained seropositive throughout the study. The presence of antibodies was followed throughout the study in seropositive European bison and for at least a year in animals that seroconverted during the observation period.

A comparison of detection methods of Alaria alata mesocercariae in wild boar (Sus scrofa) meat

Distomum musculorum suis (DMS), the mesocercariae of Alaria alata, is typically found accidently during examination of wild boar meat for Trichinella spp. The aim of the study was to compare DMS detection methods. Briefly, 232 wild boar meat samples were tested by mesocercariae migration technique (AMT) as a reference method; of these, 104 were found to be positive. Selected positive samples were tested again with the three other methods: compressorium method (Compressor), digestion with magnetic stirrer (Digestion) and by modified digestion with Pancreatin® bile and pancreatic enzymes (D + P). The results were analyzed by logistic regression, the non-parametric Kruskal-Wallis test and the Mann-Whitney U test. Of the 43 samples found positive by the AMT, 20 were found positive by Digestion and 25 by D + P. The Compressor identified DMS in seven of the 19 tested samples. The Digestion and D + P methods gave similar intensities (P = 0.506), i.e. 1.4 and 1.3 DMS respectively, but the AMT detected seven times higher number of parasites. The probability of detection of DMS in the meat sample by the Digestion or by D + P was higher than 0.5 when at least seven (Digestion) or five (D + P) DMS were present in the sample (AMT). The Compressor was the least sensitive method: at least 14 DMS must be present in the meat sample for detection. AMT should be considered the most accurate method of DMS detection.

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AMT appears the most sensitive method to detect Alaria alata mesocercariae.

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AMT results are seven times higher than in digestion methods in case of intensity.

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Compressor method is clearly inadequate to detect Alaria alata mesocercariae.

A Serological Survey of Paratuberculosis in the Polish European Bison (Bison bonasus) Population in 2018-2021

The European bison (Bison bonasus) is an endangered species which faces a range of health threats. As little is known of exposure of European bison to paratuberculosis caused by Mycobacterium avium spp. paratuberculosis, known to cause losses in cattle, the aim of the present study was to conduct serological survey in Polish bison herds. Between September 2018 and February 2021, blood samples were collected from 165 European bison from different regions of Poland. Samples were taken whenever the animals were immobilized (e.g., putting on telemetry collars) as well as from any dead animal. The serum samples were tested with ELISA. Three individuals, originating from different captive herds, were found to be seropositive. In conclusion, it was found that Mycobacterium avium subsp. paratuberculosis infections are not currently a problem in European bison, especially in free-range herds.

Antimicrobial resistance of Escherichia coli and Klebsiella spp. conventionally sampled from factory-farmed chickens - clinical submissions

INTRODUCTION

The article discusses the antimicrobial resistance of poultry-isolated bacteria in the Wielkopolska region of Poland.

MATERIAL AND METHODS

From August 2014 - June 2016, antibiotic resistance screening tests were performed involving 4,496 samples of Escherichia coli and 84 samples of Klebsiella spp., and the following antibiotics: amoxicillin, amoxicillin with clavulanic acid, colistin, doxycycline, enrofloxacin, florfenicol, neomycin, norfloxacin, spectinomycin, and trimethoprim with sulfamethoxazole. The research used broth the microdilution method and CLSI standards.

RESULTS

During the investigation period of 22 months a growing percentage of E. coli isolates showed antibiotic resistance to amoxicillin, amoxicillin with clavulanic acid, colistin, enrofloxacin, neomycin, norfloxacin, spectinomycin, and trimethoprim with sulfamethoxazole. Resistance to doxycycline and florfenicol decreased. The most efficient antibiotics against E. coli were colistin (84.64 %), neomycin (80.62 %), and amoxicillin with clavulanic acid (73.05 %). Klebsiella samples were the most susceptible to neomycin (85.71 %), colistin (84.52 %), and trimethoprim with sulfamethoxazole (73.81 %).

CONCLUSIONS

Antibiotic resistance of pathogenic micro-organisms, such as Escherichia coli and Klebsiella spp., is a serious problem both for poultry producers and for public health protection. Low efficiency of numerous antibiotic groups forces reflection on limiting the use of medicines in food-producing animals.

Prevalence of Toxoplasma gondii antibodies in wild boar (Sus scrofa) from Strzałowo Forest Division, Warmia and Mazury Region, Poland

INTRODUCTION AND OBJECTIVE

Toxoplasmosis is an important zoonosis caused by a protozoan, Toxoplasma gondii. Raw or undercooked venison may be a source of infection in humans. The aim of the study was to determine the prevalence of T. gondii antibodies in wild boar from the Strzałowo Forest Division of the Warmia and Mazury Region of Poland.

MATERIAL AND METHODS

A total of 90 samples were collected from 50 wild boar: 40 from both tongue and diaphragm muscles, 4 from diaphragm muscles and six from tongue muscles. Samples were analyzed using the commercial PrioCHECK® Toxoplasma Ab porcine ELISA, according to the manufacturer's instructions.

RESULTS

T. gondii antibodies were detected in 24 of 50 (48%) tested animals. T. gondii antibodies were detected in 40 of 90 (44.4%) tested samples (21 of tongue muscles and 19 of diaphragm muscles). In the 40 wild boar that provided samples of meat juice from the tongue and diaphragm muscles, specific antibodies were more prevalent in the tongue (20 of 40 animals - 50%) than in the diaphragm muscles (17 of 40 animals - 42.5%).

CONCLUSIONS

The study revealed a high percentage of wild boar seropositive to T. gondii. Muscle samples to obtain meat juice are easily available and simple to collect, even on the hunting grounds, which makes them suitable material for detecting T. gondii antibodies in wild boar. Wild boar are essential to T. gondii circulation in the environment, and raw or undercooked venison may be a source of human infections with this parasite.

Gene Expression Profile in Peripheral Blood Nuclear Cells of Small Ruminant Lentivirus-Seropositive and Seronegative Dairy Goats in Their First Lactation

Simple Summary

Caprine arthritis encephalitis, caused by small ruminant lentivirus (SRLV), is a disease that develops with various signs in adult goats, e.g., arthritis, mastitis, and progressive weight loss, while in goat kids, the disease presents with only neuropathy and extremely rarely. The disease results in reduced milk production and economic losses in herds of goats. Previously described changes in single gene expression do not fully explain all the processes occurring in the infected goats. Therefore, the present study describes the first use of a transcriptomic array designed specifically for goats in Poland. Its aim was to investigate the gene expression profiles of peripheral blood nuclear cells from SRLV-seropositive and SRLV-seronegative goats using a custom-made Capra hircus gene expression array. Just four genes out of ~50,000 were found to have differential expression; moreover, changes in their expression suggest an active inflammatory mechanism in SRLV-seropositive goats at the early stage of SRLV infection.

Abstract

The immune response to a viral antigen causes inflammatory cell infiltration to the tissue, which creates a suitable environment for the replication of the virus in macrophages, and the recruitment of more monocytes to the site of infection, or latently infected monocytes. The aim of the study was to analyze the transcriptomic profile of peripheral blood nuclear cells isolated from SRLV-seropositive and SRLV-negative goats at the peak of their first lactation. SRLV-seropositive goats were probably infected via colostrum. Custom transcriptomic microarrays for goats were designed and developed, namely the Capra hircus gene expression array, which features ~50,000 unique transcripts per microarray. Only four genes were differentially expressed, with up-regulated expression of the GIMAP2, SSC5D and SETX genes, and down-regulated expression of the GPR37 gene in SRLV-seropositive vs. SRLV-seronegative goats. However, in an RT-qPCR analysis, the result for the SETX gene was not confirmed. The differences in the expressions of the studied genes indicate an active inflammatory process in the SRLV-seropositive goats at the early stage of infection.

The first visually-guided bronchoscopy in European bison (Bison bonasus) - An additional tool in the diagnosis of bovine tuberculosis?

The European bison (Bison bonasus, EB) is an endangered species, and as about 1/3 of its global population is found in Poland, it is particularly important that Polish herds should be monitored. One particular concern is tuberculosis, which is not a marginal problem in wildlife in Poland, and has been microbiologically confirmed in EB, wolves (Canis lupus) and wild boar (Sus scrofa). However, ante mortem diagnosis of tuberculosis in EB is troublesome. Therefore, the present paper evaluates the potential of bronchoscopy as a diagnostic tool. Seven EB were studied, four of which were found to be naturally infected with M. caprae; in two of these, endoscopy identified abnormalities in the respiratory tract ante mortem. Therefore, despite some limitations, endoscopy can be an additional tool for diagnosing tuberculosis in EB, especially in highly valuable animals, and to assess the stage of the disease.

A Freedom of Coxiella burnetii Infection Survey in European Bison (Bison bonasus) in Poland

Simple Summary

Q fever is one of the important diseases transmissible from animals to humans. The source of infection can be numerous species of animals including mammals, birds, reptiles, amphibians as well as ticks. The role of wildlife in its epidemiology is poorly understood. Therefore, we examined 523 sera samples obtained from European bison for the presence of specific antibodies to assess whether infection occurs in this species and whether European bison may be an important source of infection in the natural environment as suggested by historical reports. The antibodies were found only in one free-living bull, while two other samples were doubtful. The results suggest the transmission of infection to the European bison was rather accidental and its role as an important source of infection nowadays is unlikely.

Abstract

Q fever is an important zoonosis caused by the intracellular Gram-negative bacteria Coxiella burnetii. The source of infection are numerous species of mammals, birds, reptiles and amphibians, as well as ticks. The disease is widespread throughout Europe, but the role of wildlife in its epidemiology is poorly understood. The European bison (Bison bonasus) population has been growing European-wide quite dynamically over the last few years. The aim of this study was to determine whether C. burnetii infection occurs in European bison and whether it can be considered an important bacterial reservoir in the natural environment. Five hundred and twenty three samples of European bison sera originating from 14 (out of the 26 existing) Polish populations were examined for the presence of specific antibodies using an ID Screen Q Fever Indirect Multi-species ELISA test. Only one (0.19%) serum sample was positive in ELISA, and two other samples were doubtful. The only seropositive animal found in this study was a free-living bull. It suggests possible transmission from domestic cattle by sharing pastures. The transmission of C. burnetii into the European bison was rather accidental in the country and its role as an important wild reservoir is unlikely. Since no tests are available for wildlife ruminants there is a need for the adaptation of the available tests.

Antibody responses in European bison (Bison bonasus) naturally infected with Mycobacterium caprae

Mycobacterium caprae, a member of the Mycobacterium tuberculosis complex, infects humans and animals causing lesions and disease like that of Mycobacterium bovis. The aim of this study was to evaluate antibody responses in European Bison (EB, Bison bonasus; a vulnerable species) naturally infected with M. caprae using dual path platform (DPP) BovidTB test and multi-antigen print immunoassay (MAPIA). Study cohorts consisted of naturally M. caprae-infected EB (n = 4), M. caprae-exposed but uninfected (n = 3), EB infected with non-tuberculous mycobacteria or other respiratory pathogens (n = 3), and negative controls (n = 19). M. caprae-infected EB were seropositive by both DPP and MAPIA; 3/4 were seropositive by DPP; and 4/4 were seropositive by MAPIA. One M. caprae-infected animal that developed generalized disease with most advanced gross lesions in the group produced the most robust antibody response. All 25 EB with no culture-confirmed M. caprae infection, including three animals exposed to M. caprae and three other animals infected with non-tuberculous pathogens, were seronegative on both tests. Antibody responses to M. caprae infection included IgM antibodies against MPB70/MPB83 and IgG antibodies to both MPB70/MPB83 and CFP10/ESAT-6. This study demonstrates the potential for use of serological assays in the ante-mortem diagnosis of M. caprae infection in EB.

Large lungworms (Nematoda: Dictyocaulidae) recovered from the European bison may represent a new nematode subspecies

Although the Dictyocaulus lungworm, the agent of dictyocaulosis, is one of parasitological threats to European bison, its systematic position remains unclear. The aim of the present study was to evaluate the morphological features of the lungworm and the pathological lesions it induces, and to analyse mitochondrial (mt) genetic markers for systematic and molecular epidemiological studies. The morphological findings indicate that Dictyocaulus lungworms of European bison can be distinguished from those of cattle on the basis of differences in buccal capsule wall length, total body length, and spicules length in males, all of which were significantly longer in those of European bison. Nucleotide diversity calculated from pairwise sequence alignments of partial cytochrome c oxidase subunit 1 (cox1), cytochrome B (cytB) and NADH dehydrogenase subunit 5 (nad5) of specimens from cattle and European bison varied from 1.7% for nad5, 2.1% for cytB, to 3.7% for cox1 gene. Thus, among the lungworms of European bison and cattle, nad5 and cytB were the most conserved proteins, whereas cox1 was the most diverse. The mt cytB marker gene may be a suitable candidate for distinguishing between the two genotypes, as nad5 demonstrated the greatest within-genus sequence variation. The lung tissue of infected European bison manifests signs of verminous pneumonia characterized by interstitial pneumonia, bronchitis and bronchiolitis. Therefore, it appears that European bison and cattle are infected with slightly diverged, morphologically-different, genotypes of D. viviparus, indicating they belong to two separate worm populations. We propose, therefore, that the lungworm of European bison should be classified as D. viviparus subsp. bisontis.

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European bison harbour a unique morphotype and genotype of Dictyocaulus viviparus.

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Mt cytB is an efficient genetic marker for studying large lungworms in bovids.

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European bison lungworm can be classified as D. viviparus subsp. bisontis.

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Pathologies induced by a newly described nematode subspecies mirrored those of lungworm in cattle.

Epidemiological characterization of Mycobacterium caprae strains isolated from wildlife in the Bieszczady Mountains, on the border of Southeast Poland

Background

The majority of animal tuberculosis (TB) cases reported in wildlife in Poland over the past 20 years have concerned the European bison inhabiting the Bieszczady Mountains in Southeast Poland: an area running along the border of Southeast Poland. As no TB cases have been reported in domestic animals in this region since 2005, any occurrence of TB in the free-living animals inhabiting this area might pose a real threat to local livestock and result in the loss of disease-free status. The aim of the study was to describe the occurrence of tuberculosis in the wildlife of the Bieszczady Mountains and determine the microbiological and molecular characteristics of any cultured strains. Lymph node samples were collected for analysis from 274 free-living animals, including European bison, red foxes, badgers, red deer, wild boar and roe deer between 2011 and 2017. Löwenstein–Jensen and Stonebrink media were used for culture. Molecular identification of strains was performed based on hsp65 sequence analysis, the GenoType®MTBC (Hain Lifescience, Germany) test, spoligotyping and MIRU-VNTR analysis.

Results

Mycobacterium caprae was isolated from the lymph nodes of 21 out of 55 wild boar (38.2%; CI 95%: 26.5%, 51.4%) and one roe deer. Since 2014, no new TB cases have been reported in the Bieszczady European bison population.

Conclusions

The identification of TB in wild boar in the Bieszczady is an alarming phenomenon, which requires further investigation. The Bieszczady mountains are a precious, unique area, home to many protected species. However, it is also the only area in Poland where TB cases have been reported in free-living animals. The occurrence of TB in wild boar inhabiting this area might pose a real threat to local livestock and many of the protected species (for example European bison that can share feeding places with wild boar). Given this situation, ongoing monitoring of the prevalence of TB should be conducted, and protective measures should be considered.

Microbiological assessment of sheep lymph nodes with lymphadenitis found during post-mortem examination of slaughtered sheep: implications for veterinary-sanitary meat control

Background

Microbiological examination of lesions found in slaughtered animals during meat inspection is an important part of public health protection as such lesions may be due to zoonotic agents that can be transmitted by meat. Examination of inflamed lymph nodes also plays a particular important role, as lymphadenitis may reflect a more widespread infection. Such lesions in sheep are mainly caused by pyogenic bacteria but also mycobacteria are occasionally found. Meat inspection data from 2017 to 2018 from southern Poland, especially from the Małopolska region, indicate that purulent or caseous lymphadenitis involving the mediastinal and tracheobronchial lymph nodes (MTLNs) is a common finding. The primary aim of the current study was to determine the aetiology of these lesions. Furthermore, it was investigated how presence of lesions was correlated with age and grazing strategy of affected sheep.

Results

Post-mortem examination revealed purulent or caseous lymphadenitis in the MTLNs of 49 out of 284 animals (17.3%). Subsequent microbiological examination revealed the presence of Corynebacterium pseudotuberculosis (34.7%), Streptococcus dysgalactiae subsp. equisimilis (34.7%), Staphylococcus aureus (8.2%), Enterococcus spp. (2.0%), Trueperella pyogenes (2.0%), and β-haemolytic strains of Escherichia coli (2.0%). Mycobacterium spp. and Rhodococcus equi were not detected. In older sheep, the probability of the presence of purulent or caseous lymphadenitis was higher than in younger, and the risk was increasing by 1.5% with each month of life. Sheep grazing locally had 4.5-times greater risk of having purulent or caseous lymphadenitis than individuals summer grazing in the mountains.

Conclusion

The most common aetiological agents of purulent or caseous lymphadenitis in the MTLNs of sheep in the Małopolska region were C. pseudotuberculosis and S. dysgalactiae subsp. equisimilis. Particular attention during post-mortem examination should be paid to the carcasses of older sheep and sheep grazing on permanent pastures, as they seem more prone to develop purulent or caseous lymphadenitis.

Pannexin-1 channel "fuels" by releasing ATP from bone marrow cells a state of sterile inflammation required for optimal mobilization and homing of hematopoietic stem cells

An efficient harvest of hematopoietic stem/progenitor cells (HSPCs) after pharmacological mobilization from the bone marrow (BM) into peripheral blood (PB) and subsequent proper homing and engraftment of these cells are crucial for clinical outcomes from hematopoietic transplants. Since extracellular adenosine triphosphate (eATP) plays an important role in both processes as an activator of sterile inflammation in the bone marrow microenvironment, we focused on the role of Pannexin-1 channel in the secretion of ATP to trigger both egress of HSPCs out of BM into PB as well as in reverse process that is their homing to BM niches after transplantation into myeloablated recipient. We employed a specific blocking peptide against Pannexin-1 channel and noticed decreased mobilization efficiency of HSPCs as well as other types of BM-residing stem cells including mesenchymal stroma cells (MSCs), endothelial progenitors (EPCs), and very small embryonic-like stem cells (VSELs). To explain better a role of Pannexin-1, we report that eATP activated Nlrp3 inflammasome in Gr-1+ and CD11b+ cells enriched for granulocytes and monocytes. This led to release of danger-associated molecular pattern molecules (DAMPs) and mitochondrial DNA (miDNA) that activate complement cascade (ComC) required for optimal egress of HSPCs from BM. On the other hand, Pannexin-1 channel blockage in transplant recipient mice leads to a defect in homing and engraftment of HSPCs. Based on this, Pannexin-1 channel as a source of eATP plays an important role in HSPCs trafficking.

Colistin Resistance of Non-pathogenic Strains of Escherichia Coli Occurring as Natural Intestinal Flora in Broiler Chickens Treated and not Treated with Colistin Sulphate

INTRODUCTION

A significant threat to public health is presented by antibiotic-resistant strains of bacteria, selective pressure on which results from antibiotic use. Colistin is an antibiotic commonly used in veterinary medicine, but also one of last resort in human medicine. Since the 2015 discovery in China of the mcr-1 gene encoding colistin resistance in Enterobacteriaceae, other countries have noted its presence. This study was to find the mcr-1 gene prevalence in E. coli isolated from poultry slaughtered in Poland.

MATERIAL AND METHODS

Cloacal swabs were taken from December 2017 to October 2018 from broiler chickens in three regions. The samples (n = 158) were grouped as flocks treated with colistin sulphate (n = 87) and those not treated (n = 71). Resistance to antimicrobials commonly used in poultry was evaluated by minimum inhibitory concentration. The presence of the mcr-1 gene was confirmed by PCR.

RESULTS

Isolates containing the mcr-1 gene were yielded by 11.27% of the samples from not treated flocks and 19.54% of those from treated flocks, but no statistically significant difference in the prevalence of the gene was seen between the groups.

CONCLUSION

The results clearly preclude intensification of selective pressure for colistin resistance due to colistin sulphate treatment because they show that the avian gastrointestinal tract was already inhabited by colistin-resistant E. coli by the time the chickens came to the poultry house.

A Novel Evidence That Mannan Binding Lectin (MBL) Pathway of Complement Cascade Activation is Involved in Homing and Engraftment of Hematopoietic Stem Progenitor Cells (HSPCs)

Delayed homing and engraftment of hematopoietic stem progenitor cells (HSPCs) or even failure to engraft at all is significant clinical problem after hematopoietic transplant. Therefore, in order to develop more efficient homing and engraftment facilitating strategies it is important to learn more about this process. Our team has postulated that myeloablative conditioning for transplantation induces in bone marrow (BM) microenvironment a state of sterile inflammation in which elements of innate immunity activated by radio- or chemotherapy conditioning for transplant play an important role. In frame with this claim we reported that a significant role in this process plays activation of complement cascade (ComC). Accordingly, mice that that lack a fifth component (C5) of ComC turned out to engraft poorly with normal syngeneic BM cells as compared to normal control animals. In extension of our previous studies we provide for first time evidence that mannan binding lectin (MBL) pathway is involved in activation of ComC in myeloablated transplant recipient BM and thus plays an important role in homing and engraftment of HSPCs. To support this MBL-KO mice show significant defect in hematopoietic reconstitution after hematopoietic transplantation. This correlates with a decrease in expression of stromal derived factor-1 (SDF-1) and impaired activation of Nlrp3 inflammasome in irradiated BM of these mice.

Usefulness of PCR-RFLP of 18S rRNA gene for rapid post-mortem diagnostics of highly pathogenic Eimeria spp. (Apicomplexa: Eimeriidae) of European bison, Bison bonasus L. with histopathological correlation

Eimeria spp. infection was investigated in 10 free-roaming European bison aged three months to 26 years by anatomopathological, histopathological, coproscopic and PCR-RFLP examination. The coproscopic study identified Eimeria oocysts in the faeces of five bison. The most prevalent morphotypes were E. bovis, present in all positive samples, and E. zuernii, in all but one. Additionally, mixed infections consisting of E. bovis, E. zuernii, E. alabamensis, E. auburnensis, E. canadensis, E. cylindrica, E. ellipsoidalis and E. subspherica were diagnosed in two bison calves. Besides being the most prevalent form, E. bovis also demonstrated the highest OPG (2,750). The presence of oocysts in the faeces was associated with those of macrogamonts, microgamonts and oocysts in the epithelium of the large intestine. Intestinal coccidiosis associated with lymphoplasmacytic enteritis was observed in many bison, not only those with positive OPG. Four animals with negative coproscopy results demonstrated early-stage gametogony in the large intestine; one case presented no endogenous stages of coccidians in the histopathological sections of the intestine, nor oocysts in the faecal samples. A 530 bp product of E. bovis 18S rDNA (GenBank: MK951685) was obtained from both the colon wall and oocysts; this was subjected to PCR-RFLP analysis based on AluI and Hin1II (NlaIII) restriction enzymes. Both samples yielded a consistent seven-band pattern, four of which (270 bp, 40 bp, 180 bp and 84 bp) were expected, and the other three represented undigested fragments. The obtained digestion pattern is indicative of Eimeria spp. infection, and can serve as a first-step diagnostic approach in detection of infection. The result of computer-based virtual digestion of the PCR product suggests that double digestion with Mval (BstNI) and KpnI restriction enzymes may be used as a second-step tool to distinguish between E. bovis, E. zuernii and E. alabamensis, all of which are highly-pathogenic species.

The occurrence of Alaria alata mesocercariae in wild boars (Sus scrofa) in north-eastern Poland

Various species of mammals, including humans and wild boars, can serve as paratenic hosts of Alaria alata mesocercariae – Distomum musculorum suis (DMS). Cases of DMS can be reliably detected by the recent introduction of the A. alata mesocercariae migration technique (AMT). The aim of this study is to present current data on the occurrence of DMS in wild boars in north-eastern Poland, and to compare the findings with those obtained in other European countries. A. alata was identified in 98 of 221 (44.3%) tissue samples of wild boar taken from five provinces in north-eastern Poland during the hunting seasons 2015–2016 and 2016–2017 based on AMT analysis. Positive results were found in all studied regions, but the percentage of infected individuals ranged from 26.3% in the Pomorskie province to 65.5% in the Warmińsko-Mazurskie province. The mean number of larvae exceeded seven larvae per 30 g sample for three provinces: Pomorskie, Mazowieckie and Lubelskie. In turn, lower values were found in the Warmińsko-Mazurskie province (3.3 larvae per 30 g), and the lowest in the Kujawsko-Pomorskie province (1.8 larvae per 30 g). The occurrence and intensity of A. alata infestation in wild boars was found to depend on the environment in which they live. Neither the sex or the age of the wild boar appeared to influence the occurrence nor the intensity of infestation.

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High percentage (44.3) of Alaria alata in samples of wild boars in Poland.

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High prevalence of A. alata infestation in wild boars compared to other reports.

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Sex does not affect the risk or intensity of infestation by A. alata in wild boars.

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Age does not affect the risk or intensity of A. alata infestation in wild boars.

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A. alata poses a potential risk for wild boar consumers in Poland.

Transboundary tuberculosis: Importation of alpacas infected with Mycobacterium bovis from the United Kingdom to Poland and potential for serodiagnostic assays in detecting tuberculin skin test false-negative animals

The present study highlights the transboundary nature of tuberculosis (TB) in alpacas and the failure of current antemortem testing protocols to identify TB-free alpaca herds and individuals for exportation. The tuberculin skin test (TST) failed to identify Mycobacterium bovis-infected animals prior to movement from the United Kingdom (UK) to Poland. This study describes the use of four serological assays [Enferplex Camelid TB, dual-path platform (DPP) VetTB and BovidTB assays, and multi-antigen print immunoassays (MAPIAs)] to detect TB in an alpaca herd with negative TST results. The breeding in Poland purchased alpacas for several years from the UK with the last group arriving in May 2018. In July 2018, two sick alpacas from the centre were hospitalized in a veterinary clinic and both died of TB a few weeks later. In November 2018, 20 alpacas remaining in this M. bovis-affected herd were euthanized and samples were collected. The study population included 20 M. bovis-infected and 20 uninfected alpacas, but only 15 infected animals were tested by all serology tests. The DPP VetTB and DPP BovidTB assays detected antibodies in 14 of the 20 infected alpacas, with results confirmed by MAPIA, and in none (MAPIA and DPP BovidTB) or one (DPP VetTB) of the 20 uninfected animals. None of the infected alpacas tested positive using the Enferplex assay. In addition, the group included three orphans and two cria-dam pairs, which provided an opportunity to analyse immune aspects of cria-mother relationships in this herd. The results suggest high susceptibility of this host species to M. bovis infection and rapid progression to disease. The serological tests used in this study offer useful tools for the detection of M. bovis infection in TST and Enferplex test non-reactive alpacas. These tests should be further evaluated for implementation into TB management and control strategies for camelid species.