Tuberculosis in Birds: Insights into the Mycobacterium avium Infections

Knowledge and Preventive Practices of Abattoir Workers toward Bovine Tuberculosis in Wolaita Zone, Southern Ethiopia

Bovine tuberculosis (bTB) is a zoonotic bacterial disease of animals that causes substantial economic losses in underdeveloped countries such as Ethiopia. A cross-sectional study was conducted from May 2021 to August 2021 in the Wolaita zone, southern Ethiopia using a designed questionnaire to assess risk, perception, and protective behavior against bTB. For this purpose, a total of 250 randomly chosen meat handlers working at six main, purposively selected abattoirs were interviewed, and the data were analyzed using STATA v. 13 software. Of the total participants interviewed, 37.0% (57/152) of the respondents strongly agreed that contracting bTB would prevent them from coming to work, whereas 32.4% (44/136) of them stayed in bed for an extended period. Knowledge-based analysis revealed that butcher house men were more aware than abattoir workers about factors related to the spread of bTB from animals to humans (73.3%), that healthy-looking meat contains bTB-causing pathogens (67.5%), and that consumption of contaminated meat can be a source of infection in humans (65.6%). These findings revealed that abattoir and butcher house employees are at higher risk of bTB exposure and a lack of understanding about the nature and transmission of the infection. Thus, abattoir and butcher house workers should be encouraged to pursue regular medical follow-ups and should be provided with better personal protective equipment.

Diagnosis of bacteria from the CMNR group in farm animals

The CMNR group comprises bacteria of the genera Corynebacterium, Mycobacterium, Nocardia, and Rhodococcus and share cell wall and DNA content characteristics. Many pathogenic CMNR bacteria cause diseases such as mastitis, lymphadenitis, and pneumonia in farmed animals, which cause economic losses for breeders and represent a threat to public health. Traditional diagnosis in CMNR involves isolating target bacteria on general or selective media and conducting metabolic analyses with the assistance of laboratory biochemical identification systems. Advanced mass spectrometry may also support diagnosing these bacteria in the clinic's daily routine despite some challenges, such as the need for isolated bacteria. In difficult identification among some CMNR members, molecular methods using polymerase chain reaction (PCR) emerge as reliable options for correct specification that is sometimes achieved directly from clinical samples such as tracheobronchial aspirates and feces. On the other hand, immunological diagnostics such as the skin test or Enzyme-Linked Immunosorbent Assay (ELISA) for Mycobacterium tuberculosis yield promising results in subclinical infections with no bacterial growth involved. In this review, we present the methods most commonly used to diagnose pathogenic CMNR bacteria and discuss their advantages and limitations, as well as challenges and perspectives on adopting new technologies in diagnostics.

Supplemental effects of different production methods of pine needle additives on growth performance, intestinal environment, meat quality and serum of broiler chickens

OBJECTIVE

Pine needles are rich in many nutrients and exhibit antibacterial and antioxidant biological activities; however, the effects of different production methods of pine needle additives on the growth performance and intestinal flora of broiler chickens are not known.

METHODS

Normal diets were supplemented with pine needle fermentation juice (PNF), pine needle soaking juice (PNS), or pine needle powder (PNP), and the associated effects on growth performance, relative organ weights, intestinal development, intestinal histological morphology, intestinal flora, meat quality, and serum indicators in broiler chickens were observed.

RESULTS

The results showed that PNF, PNS, and PNP all significantly improved feed utilisation and promoted the growth and development of broilers. All three additives also significantly improved the structure of the intestinal flora, specifically increasing the diversity of bacteria; increasing the abundance of beneficial bacteria, such as Faecalibacterium, Rikenella, and Blautia; and decreasing the abundance of harmful bacteria, such as Staphylococcus. The antioxidant properties of pine needles were also found to intensify lipid metabolic reactions in the blood, thus leading to lower triglycerides and total cholesterol. Meanwhile, high doses of PNF reduced jejunum and ileum weights and also increased meat yellowness. Lastly, none of PNF, PNS, or PNP had an effect on relative organ weights or intestinal histological morphology.

CONCLUSION

The addition of pine needles to the diet of broiler chickens can effectively promote their growth performance as well as improve their intestinal flora and serum status without side effects; in particular, the dose of 0.2% of either PNF and PNS is expected to have the capacity to replace growth-promoting antibiotics as diet additives.

Isolation of Multidrug-Resistant Mycobacterium Avium Subsp. Avium from a Wild Eurasian Otter (Lutra Lutra)

Mycobacterium avium subsp. avium is pathogenic mainly to birds, although cases of mycobacteriosis caused by these bacteria have also been reported in other animals and humans. Not much is known about the effects of this pathogen on otters. The aim of this study was to report for the first time the isolation of M. avium subsp. avium in wild otter and to describe its multidrug resistance profile. A female otter injured in a car accident was found dead and subjected to postmortem examination. Apart from the trauma changes, no other macroscopic pathological changes were detected. Bacteriologic examination revealed the presence of acid-fast bacilli in the lymph nodes, which were confirmed by molecular methods as M. avium subsp. avium. Antimicrobial susceptibility testing revealed susceptibility to clarithromycin and amikacin, but resistance to linezolid, moxifloxacin, streptomycin, isoniazid, trimethoprim/sulfamethoxazole, ciprofloxacin, doxycycline, and ethionamide. This is unusual for wild species, which generally should not come into contact with antimicrobials, and may suggest that multidrug-resistant MAC strains are circulating between wild and domestic animals. These results emphasise the need for additional epidemiological studies on non-tuberculous mycobacteria in wildlife and their implications for one health.

Unveiling insights into bovine tuberculosis: A comprehensive review

The frequent zoonotic disease known as "bovine tuberculosis" is brought on by the Mycobacterium bovis bacteria, which can infect both people and animals. The aim of this review article is to provide an explanation of the etiology, history, epidemiology, pathogenesis, clinical symptoms, diagnosis, transmission, risk factors, public health importance, economic impact, treatment, and control of bovine tuberculosis. Primarily, bovine tuberculosis affects cattle, but other animals may also be affected. Bovine tuberculosis is present throughout the world, with the exception of Antarctica. Cattle that contract bovine tuberculosis might suffer from a persistent, crippling illness. In the early stages of the disease, there are no symptoms. The tuberculin test is the primary method for detecting bovine tuberculosis in cows. Depending on its localized site in the infected animal, M. bovis can be found in respiratory secretions, milk, urine, feces, vaginal secretions, semen, feces, and exudates from lesions (such as lymph node drainage and some skin lesions). This illness generally lowers cattle productivity and could have a negative financial impact on the livestock business, particularly the dairy industry. The most effective first-line anti-tuberculosis chemotherapy consists of isoniazid, ethambutol, rifampin, and streptomycin. Second-line drugs used against bovine tuberculosis include ethionamide, capreomycin, thioacetazone, and cycloserine. To successfully control and eradicate bovine tuberculosis, developed nations have implemented routine testing and culling of infected animals under national mandatory programs.

Mycobacterial Interspersed Repeat Unit-Variable Number Tandem Repeat Typing of Mycobacterium avium Strains Isolated from the Lymph Nodes of Free-Living Carnivorous Animals in Poland

Non-tuberculous mycobacteria (NTM) are ubiquitous organisms, of which some, especially those of the Mycobacterium avium complex (MAC), may be opportunistic animal and human pathogens. Infection with NTM can interfere with tuberculosis (TB) diagnosis and induce zoonoses, especially in immunocompromised individuals. Diseases caused by NTM have become more readily recognized; however, they are likely still underestimated. In this study, we identified and genotyped Mycobacterium avium strains that were isolated during TB monitoring among free-living carnivorous animals from southeastern Poland. In 2011-2020, lymph node samples from 192 such animals were tested for mycobacteria. A total of 41 isolates of M. avium strains were detected with the use of IS901, IS900, IS1245, and mycobacterial interspersed repeat unit-variable number tandem repeat (MIRU-VNTR) identification. Thirty-three were identified as M. avium subsp. avium. These strains were derived from 1 beech marten (Martes foina), 1 common buzzard (Buteo buteo), 2 European badgers (Meles meles), 3 wolves (Canis lupus), and 26 red foxes (Vulpes vulpes). One strain isolated from a wolf was identified as M. avium subsp. hominissuis. The results show the widespread occurrence of MAC bacilli in the studied environment and additionally comprise new data on the molecular characteristics of M. avium subspecies carried by free-living southeastern Polish carnivores.

Pathological and molecular identification of Mycobacterium avium infection in a loft of domestic pigeons (Columba livia var. domestica) from India

Mycobacterium avium is a zoonotic pathogen associated with a wide range of pulmonary and extrapulmonary manifestations in a range of host species like humans, animals, and birds. The disease is more common in the avian population, and opportunistic infections have been reported in immune-compromised or debilitated animals and humans. This study reports the pathological and molecular identification of Mycobacterium avium causing avian mycobacteriosis in a loft of domestic pigeons (Columba livia var. domestica). Out of 30 pigeons aged 2-3 years, ten adult racing pigeons revealed a severe chronic and debilitating disease followed by death. The clinical signs included chronic emaciation, dullness, ruffled feathers, lameness, and greenish, watery diarrhea. Post-mortem examination of birds revealed multifocal gray- to yellow-colored raised nodules in the liver parenchyma, spleen, lungs, intestines, bone marrow, and joints. Avian mycobacteriosis was suspected based on the tissue impression smears stained by Ziehl-Neelsen staining. Histopathological examination also revealed multifocal granulomatous lesions in affected organs, which is characteristic of avian mycobacteriosis. The PCR analysis based on 16S rRNA, IS1245, and IS901 regions suggested the presence of Mycobacterium avium infection belonging to either subspecies avium or sylvaticum. This is the first detailed report of avian mycobacteriosis in pigeons from India, warranting a strict surveillance program to identify the carrier status of these microorganisms in the pigeons, which may prove a fatal zoonotic infection in humans.

Rapid detection of Mycobacterium bovis in bovine cytological smears and tissue sections by peptide nucleic acid fluorescence in-situ hybridization

BACKGROUND

Bovine tuberculosis is the leading cause of death in cattle and other species worldwide. Quick and precise identification of mycobacteria is critical to control the occurrence of tuberculosis in cattle.

METHODS

We developed a fluorescent peptide nucleic acid fluorescence in situ hybridization (PNA-FISH) approach to detect Mycobacterium bovis and Mycobacterium avium in cytological smears and tissue sections of bovines suspected of having tuberculosis. PNA-FISH was conducted on smears of lung and lymph node tissues. Standard bovine mycobacterial cultures were used to standardize the probes using 50 % formamide for M. bovis and 30 % formamide for M. avium. M. bovis probe (MTBCcy3), which was standardized at hybridization conditions of (55 °C and 40 % formamide) concentrations, was positive in all cytological smears.

RESULTS

Four out of twenty five samples tested positive in tissue sections observed as a bright red fluorescence with a cy3 filter (MTBC probe). No results were observed with (MAVTAMRA) probe for M. avium which was standardized at hybridization conditions of (55 °C and 30 % formamide). No fluorescence was observed in the control tissue sections. Additionally, the results were juxtaposed with those of other commonly used detection methods such as immunohistochemistry and Polymerase Chain Reaction (PCR) by targeting the esxA gene. None of the samples tested positive for M. avium infection.

CONCLUSION

PNA-FISH can be used to obtain cytological impression smears and tissue sections. When compared to PCR it consumes less time in the diagnosis of bovine tuberculosis in post mortem cases.

Body Size Poorly Predicts Host-Associated Microbial Diversity in Wild Birds

The composition and diversity of avian microbiota are shaped by many factors, including host ecologies and environmental variables. In this study, we examine microbial diversity across 214 bird species sampled in Malawi at five major body sites: blood, buccal cavity, gizzard, intestinal tract, and cloaca. Microbial community dissimilarity differed significantly across body sites. Ecological theory predicts that as area increases, so does diversity. We tested the hypothesis that avian microbiota diversity is correlated with body size, used as a proxy for area, using comparative phylogenetic methods. Using Pagel's lambda, we found that few microbial diversity metrics had significant phylogenetic signals. Phylogenetic generalized least squares identified a significant but weak negative correlation between host size and microbial diversity of the blood and a similarly significant but weakly positive correlation between the cloacal microbiota and host size among birds within the order Passeriformes. Phylosymbiosis, or a congruent branching pattern between host phylogeny and their associated microbiota similarity, was tested and found to be weak or not significant in four of the body sites with sufficient sample size (blood, buccal, cloaca, and intestines). Taken together, these results suggest that the avian microbiome is highly variable, with microbiota diversity demonstrating few clear associations with bird size. Finally, the blood microbiota have a unique relationship with host size. IMPORTANCE All animals coexist and interact with microorganisms, including bacteria, archaea, microscopic eukaryotes, and viruses. These microorganisms can have an enormous influence on the biology and health of macro-organisms. However, the general rules that govern these host-associated microbial communities are poorly described, especially in wild animals. In this paper, we investigate the microbial communities of over 200 species of birds from Malawi and characterize five body site bacterial microbiota in depth. Because the evolutionary relationships of the host underlie the relationship between any host-associated microbiota relationships, we use phylogenetic comparative methods to account for this relationship. We find that the size of a host (the bird) and the diversity and composition of the microbiota are largely uncorrelated. We also find that the general pattern of similarity between host phylogeny and microbiota similarity is weak. Together, we see that bird microbiota are not strongly tied to host size or evolutionary history.

Prevalence and molecular characterization of Mycobacterium tuberculosis complex in cattle and humans, Maiduguri, Borno state, Nigeria: a cross-sectional study

INTRODUCTION

Globally, the highest burden of bovine and human tuberculosis resides in Africa and Asia. Tuberculosis (TB) is the second leading single infectious killer after severe acute respiratory syndrome corona virus-2 (SARSCOV-2). Bovine TB remains a treat to wild and domesticated animals, humans and hinders international trade in endemic countries like Nigeria. We aimed at determining the prevalence of bovine and human tuberculosis, and the spoligotypes of Mycobacterium tuberculosis complex in cattle and humans in Maiduguri.

METHODS

We conducted a cross sectional study on bovine and human tuberculosis in Maiduguri, Borno state. We calculated sample size using the method of Thrusfield. Lesions suggestive of TB from 160 slaughtered cattle were obtained from Maiduguri Central Abattoir. Sputum samples from humans; 82 abattoir workers and 147 suspected TB patients from hospitals/clinics were obtained. Lesions and sputum samples were cultured for the isolation of Mycobacterium spp. Positive cultures were subjected genus typing, deletion analysis and selected isolates were spoligotyped. Data was analysed using SPSS VERSION 16.0.

RESULTS

Prevalence of 32.5% (52/160) was obtained in cattle. Damboa local government area (LGA), where majority of the infected animals were obtained from had 35.5% bTB prevalence. All categories analysed (breed, age, sex, body conformation and score) had P-values that were not significant (P > 0.05). Sputum culture revealed a prevalence of 3.7% (3/82) from abattoir workers and 12.2% from hospitals/clinics. A significant P-value (0.03) was obtained when positive culture from abattoir and that of hospitals/clinics were compared. Out of the 52 culture positive isolates obtained from cattle, 26 (50%) belonged to M. tuberculosis complex (MTC) and 17/26 (65.4%) were characterized as M. bovis. In humans, 7/12 (58.3%) MTC obtained were characterized as M. tuberculosis. Spoligotyping revealed SB0944 and SB1025 in cattle, while SIT838, SIT61 of LAM10_CAM and SIT1054, SIT46 of Haarlem (H) families were obtained from humans.

CONCLUSIONS

Cattle in Damboa LGA need to be screened for bTB as majority of the infected animals were brought from there. Our findings revealed the presence of SB0944 and SB1025 spoligotypes from cattle in Borno state. We isolated M. tuberculosis strain of the H family mainly domiciled in Europe from humans.

A review of avian mycobacteriosis: An emerging bacterial disease of public health concern

Avian mycobacteriosis is a chronic debilitating disease of birds which poses a public health threat. In avian species, the disease is primarily caused by Mycobacterium avium subspecies avium. Nearly all bird species are susceptible to this infection, with older birds being more susceptible than younger ones. Ingestion of feed and water contaminated by the excreta of infected or chronic carrier birds is the main route of Mycobacterium infection and transmission; however, the respiratory route is also possible. Migratory wild or free-living birds play an important role in mycobacteriosis transmission, and affected birds show severe depletion, emaciation, anemia, diarrhea, and respiratory manifestations. The appearance of characteristic tuberculous nodules in the digestive system, especially in the intestine, liver, and spleen, is pathognomonic. Confirmation of Mycobacterium infection can be achieved through isolation on specifically selected media, direct smear for detection of characteristic acid-fast bacilli, and detection of the bacterium using molecular diagnostic methods. Serological and allergic tests can also be applied. Different species of Mycobacterium, especially M. avium, have public health significance and can be transmitted from birds to humans. Such zoonosis is especially dangerous in human immunocompromised patients. Authorities and governments have implemented strict and comprehensive eradication programs for avian mycobacteriosis. These biosecurity measures, including surveillance monitoring programs and antimicrobial susceptibility testing, are essential for the prevention and treatment of Mycobacterium infection in poultry production systems. This review was designed to focus on avian mycobacteriosis in birds and humans.

Epidemiology, pathology, prevention, and control strategies of inclusion body hepatitis and hepatitis-hydropericardium syndrome in poultry: A comprehensive review

Infection with fowl adenoviruses (FAdVs) can result in a number of syndromes in the production of chicken, including inclusion body hepatitis (IBH), hepatitis-hydropericardium syndrome (HHS), and others, causing enormous economic losses around the globe. FAdVs are divided into 12 serotypes and five species (A-E; 1-8a and 8b-11). Most avian species are prone to infection due to the widespread distribution of FAdV strains. The genus aviadenovirus, which is a member of the adenoviridae family, is responsible for both IBH and HHS. The most popular types of transmission are mechanical, vertical, and horizontal. Hepatitis with basophilic intranuclear inclusion bodies distinguishes IBH, but the buildup of translucent or straw-colored fluid in the pericardial sac distinguishes HHS. IBH and HHS require a confirmatory diagnosis because their clinical symptoms and postmortem abnormalities are not unique to those conditions. Under a microscope, the presence of particular lesions and inclusion bodies may provide clues. Traditional virus isolation in avian tissue culture is more delicate than in avian embryonated eggs. Additionally, aviadenovirus may now be quickly and precisely detected using molecular diagnostic tools. Preventive techniques should rely on efficient biosecurity controls and immunize breeders prior to production in order to protect progeny. This current review gives a general overview of the current local and global scenario of IBH, and HHS brought on by FAdVs and covers both their issues and preventative vaccination methods.

Mycobacteriosis in Various Pet and Wild Birds from Germany: Pathological Findings, Coinfections, and Characterization of Causative Mycobacteria

A total of 50 birds diagnosed with mycobacteriosis were examined for pathomorphological lesions, coinfections, and causative agents. Mycobacterial species were identified and isolates differentiated using multilocus sequence typing (MLST) and mycobacterial interspersed repetitive-unit variable-number of tandem-repeat (MIRU-VNTR) analysis. Possible associations between mycobacterial species, pathomorphological findings, coinfections, bird orders, and husbandry conditions were evaluated statistically. Mycobacteria were isolated from 34 birds (13 of 22 Psittaciformes, 12 of 18 Passeriformes, five of six Columbiformes, and four other orders) belonging to 26 species in total. Mycobacterium genavense (Mg) was cultured from 15 birds, Mycobacterium avium subsp. avium (Maa) from 20 birds, and Mycobacterium avium subsp. hominissuis (Mah) from three birds; hence, four birds had mixed infections. About equal numbers of psittacines and passerines were infected with Ma and Mg. The genetic diversity differed; Mg isolates belonged to one MLST type, Maa to six, and Mah to three combined genotypes. Several coinfections were detected; viruses and/or endoparasites affected 44%, fungi 38%, and bacteria 29% of the birds. Pathological findings and mycobacteriosis-affected organs were independent of coinfections. Overall, gross pathological findings were more often seen in mycobacteriosis caused by Ma (95%) compared with Mg (66%). Organ distribution of mycobacteriosis was independent of the mycobacterial species. Pathomorphological changes were seen in the small intestine of 71% and the lung of 65% of the birds, suggesting oral or pulmonal ingestion of mycobacteria. There were no associations between mycobacterial species and bird orders or bird husbandry conditions. Not only Mg, but also Maa and Mah, were clearly identified as primary cause of mycobacteriosis in pet birds. IMPORTANCE In this study, the causative agents and confounding factors of mycobacteriosis in a set of pet and some wild birds from Germany were examined. Not only Mycobacterium genavense, but also M. avium subsp. avium and M. avium subsp. hominissuis, contributed to mycobacteriosis in these birds. Various coinfections did not affect the manifestation of mycobacteriosis. Due to different gross necropsy findings, however, a different pathogenicity of the two species was assumed. New strains of M. avium subsp. hominissuis originating from birds were identified and characterized, which is important for epidemiological studies and for understanding the zoonotic role of this pathogen, as the subsp. hominissuis represents an increasing public health concern. The study provides some evidence of correlation between M. avium subsp. avium genotypes and virulence which will have to be confirmed by broader studies.

Comparative Analysis of the Gut Microbiota of Three Sympatric Terrestrial Wild Bird Species Overwintering in Farmland Habitats

The gut microbiota of wild birds are affected by complex factors, and cross-species transmission may pose challenges for the host to maintain stable gut symbionts. Farmland habitats are environments strongly manipulated by humans, and the environmental characteristics within a large area are highly consistent. These features provide the ideal natural conditions for conducting cross-species comparative studies on gut microbiota among wild birds. This study aimed to investigate and compare the gut microbiota of three common farmland-dependent bird species, Great Bustard (Otis tarda dybowskii), Common Crane (Grus grus), and Common Coot (Fulica atra), in a homogeneous habitat during the wintering period. The results indicated that under the combined action of similar influencing factors, the gut microbiota of different host species did not undergo adaptive convergence, maintained relatively independent structures, and exhibited host-driven signals. In addition, we also detected various pathogenic genera that may cause outbreaks of periodic infections among sympatric migratory birds. We conclude that phylosymbiosis may occur between some wild birds and their gut microbiota. Usage of non-invasive methods to monitor the changes in the gut microbiota of wild bird fecal samples has important implications for the conservation of endangered species.

Beyond Tuberculosis: Diversity and implications of non-tuberculous mycobacteria at the wildlife-livestock interface

Non-tuberculous mycobacteria (NTM) circulate between the environment, animals and humans entailing a double concern: their ability to interfere with tuberculosis diagnosis and their potential to cause infections in their hosts. However, published records on NTM infections in animals are still scarce. The aims of the present study were to describe the diversity of NTM circulating among wild and domestic species from Spain, and to analyse their implications as potential pathogenic microorganisms or as sources of interferences in the diagnosis of bovine tuberculosis. Overall, 293 NTM isolates of 277 animals were obtained from tissue samples collected between 2012 and 2019, and analysed through a multigene approach for mycobacteria identification. Thirty-one species were identified, being M. avium subsp. avium (Maa) and M. avium subsp. hominissuis (Mah), but also M. bouchedurhonense, M. nonchromogenicum and M. lentiflavum, the most abundant ones. Maa and M. lentiflavum were isolated in several animals showing tuberculosis-like lesions. Maa, Mah and M. nonchromogenicum were recovered from many cattle that had reacted to the tuberculin skin test (TST). Other NTM were also associated to these phenomena. These four mycobacterial species were geographically associated between wild boar and other hosts. The findings of the present study suggest that a high diversity of NTM circulates among wildlife and livestock. Wild boar and M. avium seem to play a relevant role in this epidemiological scenario. This article is protected by copyright. All rights reserved.

Avian tuberculosis in a free-living Eurasian griffon vulture

Although Mycobacterium spp. often cause disease in domestic birds (chickens and companion birds), there are few data on avian tuberculosis in wild populations, especially in birds of prey. We describe here a case of a young adult female, free-living Eurasian griffon vulture (Gyps fulvus) that was found dead. Granulomas were grossly evident in the lungs at autopsy, and tuberculosis was suspected. Ziehl-Neelsen staining revealed large numbers of intracellular acid-fast-positive bacteria within granulomas. Examination on Löwenstein-Jensen medium was negative, but mycobacteria growth indicator tube medium results were positive. For the molecular detection of Mycobacterium spp., the primer set IS901F and IS901R was used. Positive results were observed on gel electrophoresis, indicating the presence of Mycobacterium avium subsp. avium DNA. Although tuberculosis is not considered to be a common cause of death in wild birds, it undoubtedly deserves special attention because vultures are generally considered to be a species resistant to a large number of pathogens. Determination of the cause of death of griffon vultures is important for future conservation measures for this sensitive wild species.

Epidemiology of Avian Tuberculosis in Selected Districts of Oromia Region, Ethiopia

Avian tuberculosis is a growing public health concern and a significant impediment to socioeconomic development, especially in developing countries, where the risk of infection is high. The disease is predominantly caused by Mycobacterium avium belonging to serotypes 1, 2, 3, and 6 (genotypes IS901 and IS1245) and Mycobacterium genavense. It mostly occurs in older birds and immunocompromised individuals due to the greater opportunity for infection with age and host immunity. A cross-sectional study anticipated to generate epidemiological information on avian tuberculosis was carried out from November 2016 to June 2017 at highland areas of Gerar Jarso, Ada’a (midland), and Boset (lowland) districts of Oromia region, Ethiopia. Two hundred seventy-three village chickens comprising local breeds, exotic breeds, and crossbreeds of both sexes were used in the study. Single intradermal avian tuberculin test, postmortem inspection of positive reactors, mycobacteriological culturing, and histopathological examination were used to assess information on the epidemiology of the disease. Subsequently, avian tuberculin test revealed an overall apparent prevalence of 11.4% (31/273) and a specific prevalence of 6.8% (6/88) in the highland, 13.4% (13/97) in the midland, and 13.6% (12/88) in the lowland study districts. Besides, it signified a higher odd of exposure in crossbreeds and females as compared to locals and males. In addition, greater odd of exposure was observed in chickens at mid- and low altitudes as compared to those at the highland. Moreover, 40.9% (9/22) of positive reactor chickens sacrificed for necropsy showed gross pathological lesions. Similarly, histopathological examination revealed a granuloma characterized by central necrosis and peripheral mononuclear lymphocytes. Nevertheless, only 0.02% (2/120) of the cultured tissues had shown colonial growth up to 12 weeks of incubation, and both were seen on sodium pyruvate-enriched Lowenstein–Jensen medium slants. Generally, the study revealed an overall increment of the apparent prevalence of avian tuberculosis with decreasing altitude. Besides, it signified a relative breed and sex variation in the risk of acquiring the disease, with crossbreeds and female chickens having higher odds of exposure.

Gut microbiome composition, not alpha diversity, is associated with survival in a natural vertebrate population

BACKGROUND

The vertebrate gut microbiome (GM) can vary substantially across individuals within the same natural population. Although there is evidence linking the GM to health in captive animals, very little is known about the consequences of GM variation for host fitness in the wild. Here, we explore the relationship between faecal microbiome diversity, body condition, and survival using data from the long-term study of a discrete natural population of the Seychelles warbler (Acrocephalus sechellensis) on Cousin Island. To our knowledge, this is the first time that GM differences associated with survival have been fully characterised for a natural vertebrate species, across multiple age groups and breeding seasons.

RESULTS

We identified substantial variation in GM community structure among sampled individuals, which was partially explained by breeding season (5% of the variance), and host age class (up to 1% of the variance). We also identified significant differences in GM community membership between adult birds that survived, versus those that had died by the following breeding season. Individuals that died carried increased abundances of taxa that are known to be opportunistic pathogens, including several ASVs in the genus Mycobacterium. However, there was no association between GM alpha diversity (the diversity of bacterial taxa within a sample) and survival to the next breeding season, or with individual body condition. Additionally, we found no association between GM community membership and individual body condition.

CONCLUSIONS

These results demonstrate that components of the vertebrate GM can be associated with host fitness in the wild. However, further research is needed to establish whether changes in bacterial abundance contribute to, or are only correlated with, differential survival; this will add to our understanding of the importance of the GM in the evolution of host species living in natural populations.

Wild animal and zoonotic disease risk management and regulation in China: Examining gaps and One Health opportunities in scope, mandates, and monitoring systems

Emerging diseases of zoonotic origin such as COVID-19 are a continuing public health threat in China that lead to a significant socioeconomic burden. This study reviewed the current laws and regulations, government reports and policy documents, and existing literature on zoonotic disease preparedness and prevention across the forestry, agriculture, and public health authorities in China, to articulate the current landscape of potential risks, existing mandates, and gaps. A total of 55 known zoonotic diseases (59 pathogens) are routinely monitored under a multi-sectoral system among humans and domestic and wild animals in China. These diseases have been detected in wild mammals, birds, reptiles, amphibians, and fish or other aquatic animals, the majority of which are transmitted between humans and animals via direct or indirect contact and vectors. However, this current monitoring system covers a limited scope of disease threats and animal host species, warranting expanded review for sources of disease and pathogen with zoonotic potential. In addition, the governance of wild animal protection and utilization and limited knowledge about wild animal trade value chains present challenges for zoonotic disease risk assessment and monitoring, and affect the completeness of mandates and enforcement. A coordinated and collaborative mechanism among different departments is required for the effective monitoring and management of disease emergence and transmission risks in the animal value chains. Moreover, pathogen surveillance among wild animal hosts and human populations outside of the routine monitoring system will fill the data gaps and improve our understanding of future emerging zoonotic threats to achieve disease prevention. The findings and recommendations will advance One Health collaboration across government and non-government stakeholders to optimize monitoring and surveillance, risk management, and emergency responses to known and novel zoonotic threats, and support COVID-19 recovery efforts.

Specific Pathogen Free - A review of strategies in agriculture, aquaculture, and laboratory mammals and how they inform new recommendations for laboratory zebrafish

Specific pathogen-free (SPF) animals are bred and managed to exclude pathogens associated with significant morbidity or mortality that may secondarily pose a risk to public health, food safety and food security, and research replicability. Generating and maintaining SPF animals requires detailed biosecurity planning for control of housing, environmental, and husbandry factors and a history of regimented pathogen testing. Successful programs involve comprehensive risk analysis and exclusion protocols that are rooted in a thorough understanding of pathogen lifecycle and modes of transmission. In this manuscript we review the current state of SPF in domestic agriculture (pigs and poultry), aquaculture (salmonids and shrimp), and small laboratory mammals. As the use of laboratory fish, especially zebrafish (Danio rerio), as models of human disease is expanding exponentially, it is prudent to define standards for SPF in this field. We use the guiding principles from other SPF industries and evaluate zebrafish pathogens against criteria to be on an SPF list, to propose recommendations for establishing and maintaining SPF laboratory zebrafish.

A Preliminary Study on Public Health Implications of Avian Tuberculosis in Selected Districts of the Oromia Region, Ethiopia

Background

Avian tuberculosis is a zoonotic disease which remains a problem in extensive poultry production systems under which chickens scavenge for survival in unhygienic environments. Methodology. A cross-sectional study was conducted from November 2016 to June 2017 at high-land areas of Gerar Jarso and Ada'a and Boset districts located at mid and low altitudes of Oromia, Ethiopia, respectively, to assess the perception of farmers on the occurrence of avian tuberculosis in chickens and its public health implications using a semistructured questionnaire.

Result

The study evidenced poor awareness of the farmers, as only 11% (10/91) of them had well-perceived occurrence of the disease in chickens and its risk of zoonosis.

Conclusion

Hence, it revealed that there is poor public perception on the occurrence as well as public health implications of avian tuberculosis, demanding further studies for verification and technical interventions.

Comparative Genomics of Mycobacterium avium Complex Reveals Signatures of Environment-Specific Adaptation and Community Acquisition

Nontuberculous mycobacteria, including those in the Mycobacterium avium complex (MAC), constitute an increasingly urgent threat to global public health. Ubiquitous in soil and water worldwide, MAC members cause a diverse array of infections in humans and animals that are often multidrug resistant, intractable, and deadly. MAC lung disease is of particular concern and is now more prevalent than tuberculosis in many countries, including the United States. Although the clinical importance of these microorganisms continues to expand, our understanding of their genomic diversity is limited, hampering basic and translational studies alike. Here, we leveraged a unique collection of genomes to characterize MAC population structure, gene content, and within-host strain dynamics in unprecedented detail. We found that different MAC species encode distinct suites of biomedically relevant genes, including antibiotic resistance genes and virulence factors, which may influence their distinct clinical manifestations. We observed that M. avium isolates from different sources—human pulmonary infections, human disseminated infections, animals, and natural environments—are readily distinguished by their core and accessory genomes, by their patterns of horizontal gene transfer, and by numerous specific genes, including virulence factors. We identified highly similar MAC strains from distinct patients within and across two geographically distinct clinical cohorts, providing important insights into the reservoirs which seed community acquisition. We also discovered a novel MAC genomospecies in one of these cohorts. Collectively, our results provide key genomic context for these emerging pathogens and will facilitate future exploration of MAC ecology, evolution, and pathogenesis.

IMPORTANCE Members of the Mycobacterium avium complex (MAC), a group of mycobacteria encompassing M. avium and its closest relatives, are omnipresent in natural environments and emerging pathogens of humans and animals. MAC infections are difficult to treat, sometimes fatal, and increasingly common. Here, we used comparative genomics to illuminate key aspects of MAC biology. We found that different MAC species and M. avium isolates from different sources encode distinct suites of clinically relevant genes, including those for virulence and antibiotic resistance. We identified highly similar MAC strains in patients from different states and decades, suggesting community acquisition from dispersed and stable reservoirs, and we discovered a novel MAC species. Our work provides valuable insight into the genomic features underlying these versatile pathogens.

Emerging MDR-Mycobacterium avium subsp. avium in house-reared domestic birds as the first report in Egypt

Background

Avian tuberculosis is a chronic and zoonotic disease that affects a wide variety of birds, mammals, and humans. This study aimed to estimate the frequency of Mycobacterium avium subsp. avium in some domestic birds based on molecular diagnosis, antibiogram profile, and PCR-based detection of inhA, rpoB, rpsL, and otrB antibiotic resistance-related genes.

Methods

A total of 120 fecal samples were collected from small flocks of house-reared domestic birds at Ismailia Governorate, Egypt. The collected samples were processed and subjected to the bacteriological examination. The antimicrobial susceptibility testing of the recovered isolates was performed using the broth microdilution method for the detection of minimum inhibitory concentrations (MICs). The genetic detection of the IS901confirmatory gene, inhA, rpoB, rpsL, and otrB genes was carried out using PCR.

Results

The frequency of M. avium subsp. avium was 4.1% (5/120); 10% (4/40) in ducks, and 2.5% (1/10) in geese. The identification of the recovered isolates was confirmed using PCR, where all the tested isolates were positive for IS901confirmatory gene. The results of the broth microdilution method revealed that most of the recovered isolates exhibited multidrug resistance (MDR) to isoniazid, rifampicin, streptomycin, oxytetracycline, and doxycycline, and harbored the inhA, rpoB, rpsL, and otrB genes.

Conclusion

In brief, to the best of our knowledge this is the first report that emphasized the emergence of avian tuberculosis in house-reared domestic birds in Egypt. The emergence of MDR- M. avium subsp. avium is considered a public health threat. Emerging MDR-M. avium subsp. avium in domestic birds are commonly harbored the IS901, inhA, rpoB, rpsL, and otrB genes. Azithromycin and clofazimine revealed a promising in-vitro antibacterial activity against M. avium subsp. avium.

Hematologic values in domestic pigeons naturally infected with Mycobacterium avium subsp. avium

Avian mycobacteriosis is an important disease of birds and is most often caused by Mycobacterium avium or Mycobacterium genavense. However, little information on the hematologic changes associated with this infectious disease in pigeons has been published. The aim of this investigation was to compare the hematologic parameters of domestic pigeons (Columba livia var. domestica) naturally infected with M avium subsp. avium (MAA) with clinically healthy pigeons. Blood samples were collected from 12 pigeons with suspected mycobacteriosis and 12 clinically healthy pigeons. All the birds with suspect infections were necropsied, and affected organs were cultured and examined on histopathology for mycobacteriosis. Total leukocyte and erythrocyte counts were performed on each blood sample with the Natt and Herrick method using a Neubauer hemocytometer. White blood cell (WBC) differential counts were performed on Giemsa-stained blood smears. Packed cell volumes (PCVs) were measured using the microhematocrit technique. Hemoglobin concentrations were measured with a spectrophotometer using the cyanomethemoglubin method. Mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentrations (MCHCs), and mean cell volumes (MCVs) were calculated manually. All of the infected birds had typical histopathologic findings of avian mycobacteriosis, which were confirmed using microbiologic and molecular methods to detect MAA. The hematologic data from the two groups were compared. The total WBC, heterophil, lymphocyte, and monocyte counts were significantly higher, and the PCV, HGB, MCH, and MCHC values were significantly lower in the infected birds compared with the clinically healthy pigeons.

MAP, Johne's disease and the microbiome; current knowledge and future considerations

Mycobacterium avium subsp. paratuberculosis is the causative agent of Johne's disease in ruminants. As an infectious disease that causes reduced milk yields, effects fertility and, eventually, the loss of the animal, it is a huge financial burden for associated industries. Efforts to control MAP infection and Johne's disease are complicated due to difficulties of diagnosis in the early stages of infection and challenges relating to the specificity and sensitivity of current testing methods. The methods that are available contribute to widely used test and cull strategies, vaccination programmes also in place in some countries. Next generation sequencing technologies have opened up new avenues for the discovery of novel biomarkers for disease prediction within MAP genomes and within ruminant microbiomes. Controlling Johne's disease in herds can lead to improved animal health and welfare, in turn leading to increased productivity. With current climate change bills, such as the European Green Deal, targeting livestock production systems for more sustainable practices, managing animal health is now more important than ever before. This review provides an overview of the current knowledge on genomics and detection of MAP as it pertains to Johne's disease.

Diagnostic Sequences That Distinguish M. avium Subspecies Strains

Over a decade ago Mycobacterium avium subspecies paratuberculosis (Map) specific genes were initially identified in a whole genome context by comparing draft genome sequences of Map strain K-10 with Mycobacterium avium subspecies hominissuis (Mah) strain 104. This resulted in identification of 32 Map specific genes, not including repetitive elements, based on the two-genome comparison. The goal of this study was to define a more complete catalog of M. avium subspecies-specific genes. This is important for obtaining additional diagnostic targets for Johne's disease detection and for understanding the unique biology, evolution and niche adaptation of these organisms. There are now over 28 complete genome sequences representing three M. avium subspecies, including avium (Maa), Mah, and Map. We have conducted a comprehensive comparison of these genomes using two independent pan genomic comparison tools, PanOCT and Roary. This has led to the identification of more than 250 subspecies defining genes common to both analyses. The majority of these genes are arranged in clusters called genomic islands. We further reduced the number of diagnostic targets by excluding sequences having high BLAST similarity to other mycobacterial species recently added to the National Center for Biotechnology Information database. Genes identified as diagnostic following these bioinformatic approaches were further tested by DNA amplification PCR on an additional 20 M. avium subspecies strains. This combined approach confirmed 86 genes as Map-specific, seven as Maa-specific and three as Mah-specific. A single-tube PCR reaction was conducted as a proof of concept method to quickly distinguish M. avium subspecies strains. With these novel data, researchers can classify isolates in their freezers, quickly characterize clinical samples, and functionally analyze these unique genes.

Avian Mycobacteriosis and Molecular Identification of Mycobacterium avium Subsp. avium in Racing Pigeons (Columba livia domestica) in Greece

Simple Summary

Avian mycobacteriosis a contagious, chronic and potential zoonotic List B disease of the World Organization for Animal Health, is described in two lofts of pigeons in this review. Molecular analysis identified the causative agent as Mycobacterium avium subsp. avium. This is the first case report of avian mycobacteriosis in Greece, which describes the presence of granulomatous conjunctivitis and the molecular identification of M. avium subsp. avium as the causative agent in racing pigeons. The identification of the strain will enrich the epidemiological data and will contribute to the control of avian mycobacteriosis in pigeons.

Abstract

In this report, cases of avian mycobacteriosis in two lofts of racing pigeons are described. Three racing pigeons of 2-year old from the first loft (A) and four racing pigeons of 4–5 years old from the second loft (B) were submitted to the Unit of Avian Medicine for clinical examination and necropsy. In the case history chronic and debilitating disease was reported. The clinical signs included emaciation, depression, lameness, periorbital swelling and diarrhea, although the appetite was normal. Post mortem lesions involved an enlarged spleen with multiple different sized yellow nodules. Similar lesions were also observed in the liver, conjunctiva of the inferior eyelids and in the femoral bone marrow. The suspicion of avian mycobacteriosis was based on history, clinical signs and typical lesions. In order to confirm the diagnosis, histopathology was performed on tissue sections and revealed the presence of multiple granulomas with central necrosis. In addition, Ziehl-Neelsen positive bacilli were observed in histological sections and smears from the granulomas of the affected tissues. Molecular analysis identified the causative agent as Mycobacterium avium subsp. avium. This is the first case report of avian mycobacteriosis in Greece, which describes the presence of granulomatous conjunctivitis and the molecular identification of M. avium subsp. avium as the causative agent in racing pigeons.

Outbreak of avian mycobacteriosis in a commercial turkey breeder flock

Avian mycobacteriosis (AM) is a chronic and contagious disease of pet birds, captive exotic, wild and domestic fowl, and mammals. Mycobacterium avium subsp. avium is the most common cause of AM in poultry. For the first time, we report a chronic outbreak of AM in an Iranian breeder flock of 250 45-week-old turkeys (Meleagris gallopavo) with a morbidity and mortality rate of 91.6% and 80%, respectively. A well-defined clinical feature of the outbreak included a progressive weight loss, decreased egg production, listlessness, and lameness. Tuberculous nodules were seen on liver, spleen, ovary, and ribs. Granulomatous inflammation and acid-fast bacilli were confirmed by using Ziehl-Neelsen method on hepatic lesions. M. avium subsp. avium was identified by polymerase chain reaction techniques based on the presence of 16S ribosomal RNA gene and insertion elements IS1245 and IS901. In this report, we not only describe the epidemiological, pathological, and molecular characteristics of the outbreak in detail, but we also discuss multiple factors influencing the introduction and development of AM critically. In this case, wild feral pigeons might have been the source of infection, but further molecular-epidemiology studies are needed to understand the role of wild birds in the persistence and transmission of Mycobacterium.RESEARCH HIGHLIGHTS First report of avian mycobacteriosis in an Iranian commercial turkey flock is described in detail.Risk factors intrinsic to the bird and mycobacteria, as well as extrinsic factors influencing the introduction and development of avian mycobacteriosis in birds, are critically discussed.

RETROSPECTIVE REVIEW OF MORTALITY IN CAPTIVE PINK PIGEONS (NESOENAS MAYERI) HOUSED IN EUROPEAN COLLECTIONS: 1977-2018

The Mauritian pink pigeon (Nesoenas mayeri) is vulnerable, with only 400 individuals remaining in the free-living population. A European captive population was established in 1977 and a European Endangered Species Program (EEP) in 1992. The EEP long-term management plan recommends integrating the EEP and free-living Mauritius populations through pigeon transfers. A retrospective mortality review of the captive population was performed as part of a disease risk assessment process and to inform infectious disease screening prior to exporting captive birds to Mauritius. Six hundred pink pigeons from 34 institutions died from 1977 to 2018. Each individual was categorized according to age at time of death. Records from 404 individuals were categorized according to cause of death. Neonatal mortality (39%) and juvenile mortality (10.8%) were most commonly caused by noninfectious diseases (52% and 54.4%, respectively), including parental neglect and failure to thrive in neonates and nutritional secondary hyperparathyroidism in juveniles. Trauma (43.1%) was the most common cause of mortality in adults, with significantly higher mortality in males from interspecific aggression and in females due to intraspecific aggression. Yersinia pseudotuberculosis, Mycobacterium avium, and Escherichia coli were the most common infectious causes of adult mortality, and E. coli was the most common infectious cause in neonates. The following infectious diseases were identified as priorities for pre-export disease risk analysis, though not all caused mortality: Y. pseudotuberculosis, M. avium, Trichomonas spp., Chlamydia psittaci, and Coccidia spp. Husbandry changes have been made over the years to mitigate many of the noninfectious causes of mortality. These include alterations to nest sites to reduce neonatal trauma and abandonment, ultraviolet light supplementation and diet optimization to reduce metabolic disorders, improving enclosure design to reduce impact trauma, allowing females rest periods during breeding season, and avoiding housing with certain species.

Drug Susceptibility of Non-tuberculous Strains of Mycobacterium Isolated from Birds from Poland

Mycobacterioses are a constant problem in backyard poultry, as well as pet birds. To date, no evidence of direct transmission of atypical bacilli between humans has been demonstrated, but it cannot be ruled out that sick animals can be a source of infection for people in their environment. The aim of the study was to identify mycobacteria isolated from birds with diagnosed mycobacteriosis and to determine the susceptibility of mycobacterial isolates from these animals to antituberculous drugs most commonly used in the treatment of mycobacterial infections in humans. For drug susceptibility tests, drugs such as isoniazid, rifampicin, streptomycin, ethambutol, ofloxacin, capreomycin, cycloserine and ethionamide were used. A high degree of drug resistance was demonstrated, particularly in Mycobacterium avium . Isolates of Mycobacterium xenopi showed a relatively good susceptibility to the drugs tested. The drug resistance of Mycobacterium genavense has not been determined, but this mycobacterium was identified in ten cases, which is the second most frequent occurrence in the cases studied.

Mycobacterioses are a constant problem in backyard poultry, as well as pet birds. To date, no evidence of direct transmission of atypical bacilli between humans has been demonstrated, but it cannot be ruled out that sick animals can be a source of infection for people in their environment. The aim of the study was to identify mycobacteria isolated from birds with diagnosed mycobacteriosis and to determine the susceptibility of mycobacterial isolates from these animals to antituberculous drugs most commonly used in the treatment of mycobacterial infections in humans. For drug susceptibility tests, drugs such as isoniazid, rifampicin, streptomycin, ethambutol, ofloxacin, capreomycin, cycloserine and ethionamide were used. A high degree of drug resistance was demonstrated, particularly in Mycobacterium avium. Isolates of Mycobacterium xenopi showed a relatively good susceptibility to the drugs tested. The drug resistance of Mycobacterium genavense has not been determined, but this mycobacterium was identified in ten cases, which is the second most frequent occurrence in the cases studied.

Analysis of the microRNA Expression Profile of Bovine Monocyte-derived Macrophages Infected with Mycobacterium avium subsp. Paratuberculosis Reveals that miR-150 Suppresses Cell Apoptosis by Targeting PDCD4

M. avium subsp. paratuberculosis (MAP) is the causative pathogen of Johne’s disease, a chronic granulomatous enteritis that principally affects ruminants and can survive, proliferate and disseminate in macrophages. MicroRNAs (miRNAs) are important regulators of gene expression and can impact the processes of cells. To investigate the role of miRNAs in monocyte-derived macrophages (MDMs) during MAP infection, we used high-throughput sequencing technology to analyze small RNA libraries of MAP-infected and control MDMs. The results showed that a total of 21 miRNAs were differentially expressed in MDMs after MAP infection, and 8864 target genes were predicted. A functional analysis showed that the target genes were mainly involved in the MAPK signaling pathway, Toll-like receptor signaling pathway, NF-kappa B signaling pathway and apoptosis. In addition, using a dual-luciferase reporter assay, flow cytometry, and a small interfering (si)RNA knockdown assay, the role of miR-150 in regulating macrophage apoptosis by targeting the programmed cell death protein-4 (PDCD4) was demonstrated. These results provide an experimental basis to reveal the regulatory mechanism of MAP infection and suggest the potential of miRNAs as biomarkers for the diagnosis of Johne’s disease in bovines.

Presence of Infected Gr-1intCD11bhiCD11cint Monocytic Myeloid Derived Suppressor Cells Subverts T Cell Response and Is Associated With Impaired Dendritic Cell Function in Mycobacterium avium-Infected Mice

Myeloid-derived suppressor cells (MDSC) are immature myeloid cells with immunomodulatory function. To study the mechanism by which MDSC affect antimicrobial immunity, we infected mice with two M. avium strains of differential virulence, highly virulent Mycobacterium avium subsp. avium strain 25291 (MAA) and low virulent Mycobacterium avium subsp. hominissuis strain 104 (MAH). Intraperitoneal infection with MAA, but not MAH, caused severe disease and massive splenic infiltration of monocytic MDSC (M-MDSC; Gr-1^intCD11b^hiCD11c^int) expressing inducible NO synthase (Nos2) and bearing high numbers of mycobacteria. Depletion experiments demonstrated that M-MDSC were essential for disease progression. NO production by M-MDSC influenced antigen-uptake and processing by dendritic cells and proliferation of CD4⁺ T cells. M-MDSC were also induced in MAA-infected mice lacking Nos2. In these mice CD4⁺ T cell expansion and control of infection were restored. However, T cell inhibition was only partially relieved and arginase (Arg) 1-expressing M-MDSC were accumulated. Likewise, inhibition of Arg1 also partially rescued T cell proliferation. Thus, mycobacterial virulence results in the induction of M-MDSC that block the T cell response in a Nos2- and Arg1-dependent manner.

Mycobacterium xenopi systemic infection in a domestic fiery-shouldered conure bird (Pyrrhura egregia)

Introduction

Mycobacterium xenopi is a rare opportunistic pathogen mainly causing infections in immunocompromised human patients or those with underlying chronic structural lung disease. Cases of disease in veterinary medicine remain scarce. Few animal species, including birds, are suspected of being vectors of the disease and there has not yet been a report of clinical disease in birds. We report the first case, to our knowledge, of systemic infection in a domestic bird.

Case presentation

A female fiery-shouldered conure was submitted after death for necropsy following episodes of heavy breathing. The necropsy revealed multiple granulomatous lesions within the liver, air sacs and kidneys. Ziehl–Neelsen stains demonstrated the presence of numerous intralesional acid-fast bacilli. PCR assays and culture confirmed the presence of M. xenopi.

Conclusion

Through this case we hope to describe the characteristics of M. xenopi disease in birds and the possible close relationship between animal and human infections.

Isolation, Identification, and Characterization of a New Highly Pathogenic Field Isolate of Mycobacterium avium spp. avium

Avian tuberculosis is a chronic, contagious zoonotic disease affecting birds, mammals, and humans. The disease is most often caused by Mycobacterium avium spp. avium (MAA). Strain resources are important for research on avian tuberculosis and vaccine development. However, there has been little reported about the newly identified MAA strain in recent years in China. In this study, a new strain was isolated from a fowl with symptoms of avian tuberculosis by bacterial culture. The isolated strain was identified to be MAA by culture, staining, and biochemical and genetic analysis, except for different colony morphology. The isolated strain was Ziehl-Zeelsen staining positive, resistant to p-nitrobenzoic acid, and negative for niacin production, Tween-80 hydrolysis, heat stable catalase and nitrate production. The strain had the DnaJ gene, IS1245, and IS901, as well. Serum agglutination indicated that the MAA strain was of serotype 1. The MAA strain showed strong virulence via mortality in rabbits and chickens. The prepared tuberculin of the MAA strain had similar potency compared to the MAA reference strain and standard tuberculin via a tuberculin skin test. Our studies suggested that this MAA strain tends to be a novel subtype, which might enrich the strain resource of avian tuberculosis.

Galliformes and Columbiformes

Galliformes and columbifomes are closely associated with humans and some species have been domesticated for well over 5000 years. Both orders remain diverse, ranging from the common domestic poultry species (e.g., chicken, turkey, and squabs) to the more exotic species found in the wild and in zoological collections. While many species have been benefited from human activities and have increased their ranges, others have declined in numbers and some have become threatened (e.g., Trinidad piping-guan and wood quail) or even extinct (e.g., dodo and passenger pigeon). Nondomestic galliformes and columbiformes are susceptible to many of the same diseases that occur in domestic species, yet predisposition may be different. Furthermore, disease prevalence depends on exposure and potential risk factors. Infectious diseases that tend to be more common under intensive commercial production may not pose as great a risk to exotic and free-living species.

Molecular Detection of Mycobacterium avium avium and Mycobacterium genavense in Feces of Free-living Scarlet Macaws ( Ara macao) in Costa Rica

We conducted a study of the two main populations of free-living Scarlet Macaws ( Ara macao) in Costa Rica to detect the causal agents of avian tuberculosis using noninvasive techniques. We analyzed 83 fecal samples collected between February and May 2016 from the central and southern Pacific areas in the country. Using PCR, we first amplified the 16S region of the ribosomal RNA, common to all Mycobacterium species. Then, products from the insertion sequence IS901 and from a 155-base pair DNA fragment evidenced the presence of the avian pathogenic Mycobacterium avium subsp. avium strain and a Mycobacterium genavense strain, respectively. Seven of 38 (18%) samples collected in the central Pacific area were positive for Mycobacterium spp. and 3 of 38 (8%) were positive for M. genavense, with one sample amplifying regions for both. Two of the 45 (4%) samples collected in the south Pacific area of Costa Rica were positive to M. a. avium. Our detection of avian tuberculosis pathogens in free-living Scarlet Macaws suggests that free-living macaws could excrete in their feces M. genavense, bird-pathogenic M. a. avium, and possibly other Mycobacteria (not detected in our study).

MYCOBACTERIOSIS IN CAPTIVE PSITTACINES: A BRIEF REVIEW AND CASE SERIES IN COMMON COMPANION SPECIES (ECLECTUS RORATUS, AMAZONA ORATRIX, AND PIONITES MELANOCEPHALA)

In 2015, three psittacines were presented within 30 days, each with differing clinical signs and patient histories. A 13-yr-old male eclectus parrot (Eclectus roratus) was presented for weakness, depression, and acute anorexia. On presentation it was determined to have a heart murmur, severely elevated white blood cell count (93.9 10³/μl) with a left shift (2.8 10³/μl bands), and anemia (30%). Severe hepatomegaly was noted on radiographs, ultrasonography, and computed tomography. A cytological sample of the liver obtained through a fine needle aspirate revealed intracellular acid-fast bacilli identified as Mycobacterium avium. A 20-yr-old female double yellow-headed Amazon parrot (Amazona oratrix) was presented for a 1-mo history of lethargy and weight loss despite a good appetite. The parrot's total white blood cell count was 16.8 10³/μl and the PCV was 35%. Following its death, a necropsy revealed a generalized granulomatous condition that involved the small intestines, lungs, liver, spleen, and medullary cavities of the long bones, with intracellular acid-fast bacilli identified as Mycobacterium genavense. The third case, an 18-mo-old female black-headed caique (Pionites melanocephala), was presented with a 1-day history of lethargy and depression. On presentation, the caique had a heart murmur, distended coelom, palpable thickening of the coelomic organs, and increased lung sounds. Following the caique's death, a complete necropsy revealed mycobacteriosis of the liver, spleen, small intestines, pericardial fat, and bone marrow. The infection was identified as Mycobacterium genavense. The importance of advances in Mycobacterium spp. identification, continued presence of this organism in captive avian populations, difficulty in obtaining a definitive antemortem diagnosis, and conflicting recommendations regarding treatment are thought-provoking areas of focus in this case series.

Antimicrobial Resistance in Bacterial Poultry Pathogens: A Review

Antimicrobial resistance (AMR) is a global health threat, and antimicrobial usage and AMR in animal production is one of its contributing sources. Poultry is one of the most widespread types of meat consumed worldwide. Poultry flocks are often raised under intensive conditions using large amounts of antimicrobials to prevent and to treat disease, as well as for growth promotion. Antimicrobial resistant poultry pathogens may result in treatment failure, leading to economic losses, but also be a source of resistant bacteria/genes (including zoonotic bacteria) that may represent a risk to human health. Here we reviewed data on AMR in 12 poultry pathogens, including avian pathogenic Escherichia coli (APEC), Salmonella Pullorum/Gallinarum, Pasteurella multocida, Avibacterium paragallinarum, Gallibacterium anatis, Ornitobacterium rhinotracheale (ORT), Bordetella avium, Clostridium perfringens, Mycoplasma spp., Erysipelothrix rhusiopathiae, and Riemerella anatipestifer. A number of studies have demonstrated increases in resistance over time for S. Pullorum/Gallinarum, M. gallisepticum, and G. anatis. Among Enterobacteriaceae, APEC isolates displayed considerably higher levels of AMR compared with S. Pullorum/Gallinarum, with prevalence of resistance over >80% for ampicillin, amoxicillin, tetracycline across studies. Among the Gram-negative, non-Enterobacteriaceae pathogens, ORT had the highest levels of phenotypic resistance with median levels of AMR against co-trimoxazole, enrofloxacin, gentamicin, amoxicillin, and ceftiofur all exceeding 50%. In contrast, levels of resistance among P. multocida isolates were less than 20% for all antimicrobials. The study highlights considerable disparities in methodologies, as well as in criteria for phenotypic antimicrobial susceptibility testing and result interpretation. It is necessary to increase efforts to harmonize testing practices, and to promote free access to data on AMR in order to improve treatment guidelines as well as to monitor the evolution of AMR in poultry bacterial pathogens.

Applying the One Health Concept to Mycobacterial Research - Overcoming Parochialism

Mycobacterial infections remain a public health problem. Historically important, globally ubiquitous and with a wide host range, we are still struggling to control mycobacterial infections in humans and animals. While previous reviews have focused on individual mycobacterial infections in either humans or animals, a comprehensive review of the zoonotic aspect of mycobacteria in the context of the One Health initiative is lacking. With the purpose of providing a concise and comprehensive resource, we have collated literature to address the zoonotic potential of different mycobacterial species and elaborate on the necessity for an inter-sectorial approach to attain a new vision to combat mycobacterial infections.

Infectious Diseases

The chapter describes bacerial, viral, parasitic and fungal infections commonly detected in pet birds. The chapter includes history, etiology, susceptible hosts, transmission, pathogenesis, clinical symptoms, lesion, diagnosis, zoonosis, Treatment and control strategy of Tuberculosis, Salmonellosis, Chlamydiosis, Campylobacteriosis, Lyme disease, other bacterial infection, Newcastle disease, Avian Influenza infection, West Nile Virus infection, Usutu virus infection, Avian Borna Virus infection, Beak and feather disease, other viral infection, Toxoplasmosis, Giardiasis, Cryptosporidiosis, other parasitic infection, Cryptococcosis, Aspergillosis, Other fungal infections.

Attenuated heme oxygenase-1 responses predispose the elderly to pulmonary nontuberculous mycobacterial infections

Pulmonary infections with nontuberculous mycobacteria (P-NTM), such as by Mycobacterium avium complex (M. avium), are increasingly found in the elderly, but the underlying mechanisms are unclear. Recent studies suggest that adaptive immunity is necessary, but not sufficient, for host defense against mycobacteria. Heme oxygenase-1 (HO-1) has been recognized as a critical modulator of granuloma formation and programmed cell death in mycobacterial infections. Old mice (18-21 mo) infected with M. avium had attenuated HO-1 response with diffuse inflammation, high burden of mycobacteria, poor granuloma formation, and decreased survival (45%), while young mice (4-6 mo) showed tight, well-defined granuloma, increased HO-1 expression, and increased survival (95%). To further test the role of HO-1 in increased susceptibility to P-NTM infections in the elderly, we used old and young HO-1^+/+ and HO-1^-/- mice. The transcriptional modulation of the JAK/STAT signaling pathway in HO-1^-/- mice due to M. avium infection demonstrated similarities to infected wild-type old mice with upregulation of SOCS3 and inhibition of Bcl2. Higher expression of SOCS3 with downregulation of Bcl2 resulted in higher macrophage death via cellular necrosis. Finally, peripheral blood monocytes (PBMCs) from elderly patients with P-NTM also demonstrated attenuated HO-1 responses after M. avium stimulation and increased cell death due to cellular necrosis (9.69% ± 2.02) compared with apoptosis (4.75% ± 0.98). The augmented risk for P-NTM in the elderly is due, in part, to attenuated HO-1 responses, subsequent upregulation of SOCS3, and inhibition of Bcl2, leading to programmed cell death of macrophages, and sustained infection.

Molecular analysis and MIRU-VNTR typing of Mycobacterium avium subsp. avium, 'hominissuis' and silvaticum strains of veterinary origin

Besides Mycobacterium avium subsp. paratuberculosis (MAP), M. avium subsp. avium (MAA), M. avium subsp. silvaticum (MAS), and 'M. avium subsp. hominissuis' (MAH) are equally important members of M. avium complex, with worldwide distribution and zoonotic potential. Genotypic discrimination is a prerequisite to epidemiological studies which can facilitate disease prevention through revealing infection sources and transmission routes. The primary aim of this study was to identify the genetic diversity within 135 MAA, 62 MAS, and 84 MAH strains isolated from wild and domestic mammals, reptiles and birds. Strains were tested for the presence of large sequence polymorphism LSP(A)17 and were submitted to Mycobacterial interspersed repetitive units-variable-number tandem repeat (MIRU-VNTR) analysis at 8 loci, including MIRU1, 2, 3, and 4, VNTR25, 32, and 259, and MATR9. In 12 strains hsp65 sequence code type was also determined. LSP(A)17 was present only in 19.9% of the strains. All LSP(A)17 positive strains belonged to subspecies MAH. The discriminatory power of the MIRU-VNTR loci set used reached 0.9228. Altogether 54 different genotypes were detected. Within MAH, MAA, and MAS strains 33, 16, and 5 different genotypes were observed. The described genotypes were not restricted to geographic regions or host species, but proved to be subspecies specific. Our knowledge about MAS is limited due to isolation and identification difficulties. This is the first study including a large number of MAS field strains. Our results demonstrate the high diversity of MAH and MAA strains and the relative uniformity of MAS strains.

Genotyping of Mycobacterium avium subsp. avium isolates from naturally infected lofts of domestic pigeons in Ahvaz by IS901 RFLP

BACKGROUND AND OBJECTIVES

Avian tuberculosis is one of the most important infections affecting most species of birds. Mycobacterium avium can not only infect all species of birds, but also infect some domesticated mammals. The most crucial aspect of control and eradication scheme is identification of infection sources and transmission routs. Molecular techniques such as restriction fragment length polymorphism and pulse field gel electrophoresis have been shown to be much more discriminatory and suitable for use in the epidemiological study.

MATERIALS AND METHODS

Eighty suspected pigeons to avian tuberculosis based on their clinical signs, were subjected to the study. Forty Mycobacterium avium subsp. avium isolates out of a total of 51 identified isolates were subjected to the test.

RESULTS

IS901-RFLP using Pvu II was successfully conducted and produced 7 patterns. The majority of isolates (60%) were RFLP type PI.1. This type was the most similar type to standard strain. However, all the patterns obtained in this study were different from the standard strain.

CONCLUSION

The result of this study indicate that these isolates probably are limited to Khuzestan region. We recommend DNA fingerprinting differentiation of non tuberculous Mycobacteria particularly Mycobacterium avium complex isolated from infected birds and human to possibly find source of infections.

The Mycobacterium avium ssp. paratuberculosis specific mptD gene is required for maintenance of the metabolic homeostasis necessary for full virulence in mouse infections

Mycobacterium avium subspecies paratuberculosis (MAP) causes Johne's disease, a chronic granulomatous enteritis in ruminants. Furthermore, infections of humans with MAP have been reported and a possible association with Crohn's disease and diabetes type I is currently discussed. MAP owns large sequence polymorphisms (LSPs) that were exclusively found in this mycobacteria species. The relevance of these LSPs in the pathobiology of MAP is still unclear. The mptD gene (MAP3733c) of MAP belongs to a small group of functionally uncharacterized genes, which are not present in any other sequenced mycobacteria species. mptD is part of a predicted operon (mptABCDEF), encoding a putative ATP binding cassette-transporter, located on the MAP-specific LSP14. In the present study, we generated an mptD knockout strain (MAPΔmptD) by specialized transduction. In order to investigate the potential role of mptD in the host, we performed infection experiments with macrophages. By this, we observed a significantly reduced cell number of MAPΔmptD early after infection, indicating that the mutant was hampered with respect to adaptation to the early macrophage environment. This important role of mptD was supported in mouse infection experiments where MAPΔmptD was significantly attenuated after peritoneal challenge. Metabolic profiling was performed to determine the cause for the reduced virulence and identified profound metabolic disorders especially in the lipid metabolism of MAPΔmptD. Overall our data revealed the mptD gene to be an important factor for the metabolic adaptation of MAP required for persistence in the host.

Facts, myths and hypotheses on the zoonotic nature of Mycobacterium avium subspecies paratuberculosis

Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of paratuberculosis (Johne's disease [JD]), a chronic granulomatous enteritis in ruminants. JD is one of the most widespread bacterial diseases of domestic animals with significant economic impact. The histopathological picture of JD resembles that of Crohn's disease (CD), a human chronic inflammatory bowel disease of still unresolved aetiology. An aetiological relevance of MAP for CD has been proposed. This and the ambiguity of other published epidemiological findings raise the question whether MAP represents a zoonotic agent. In this review, we will discuss evidence that MAP has zoonotic capacity.