Antibiotic Susceptibility, Resistance Gene Determinants and Corresponding Genomic Regions in Lactobacillus amylovorus Isolates Derived from Wild Boars and Domestic Pigs

Restrictions on the use of antibiotics in pigs lead to the continuous search for new probiotics serving as an alternative to antibiotics. One of the key parameters for probiotic bacteria selection is the absence of horizontally transmissible resistance genes. The aim of our study was to determine antibiotic susceptibility profiles in 28 Lactobacillus amylovorus isolates derived from the digestive tract of wild boars and farm pigs by means of the broth microdilution method and whole genome sequencing (WGS). We revealed genetic resistance determinants and examined sequences flanking resistance genes in these strains. Our findings indicate that L. amylovorus strains from domestic pigs are predominantly resistant to tetracycline, erythromycin and ampicillin. WGS analysis of horizontally transmissible genes revealed only three genetic determinants (tetW, ermB and aadE) of which all tetW and ermB genes were present only in strains derived from domestic pigs. Sequence analysis of coding sequences (CDS) in the neighborhood of the tetW gene revealed the presence of site-specific recombinase (xerC/D), site-specific DNA recombinase (spoIVCA) or DNA-binding transcriptional regulator (xre), usually directly downstream of the tetW gene. In the case of ermB, CDS for omega transcriptional repressor or mobilization protein were detected upstream of the ermB gene

Eradication of Bovine Mastitis Caused by the Pathogenic Microalga <i>Prototheca bovis</i> on a Dairy Cattle Farm: A Case Report

The achlorophyllous unicellular microalga of the genus Prototheca, a causative agent of bovine mammary gland infection, is receiving increasing attention in the field of veterinary medicine. Mastitis caused by these algae leads to significant economic losses for farmers worldwide and represents a source of threat to raw milk quality and dairy food-chain safety. This case report describes an outbreak of bovine mastitis in dairy cattle caused by Prototheca bovis and the on-farm practices that resulted in the recovery of the affected herd and elimination of the presence of Prototheca spp. in the farm environment. Effective management strategies that played a crucial role in protothecosis eradication included regular screening, timely identification, strict separation of Prototheca-positive cows, a change of housing regime associated with the utilisation of straw mattresses and removal of deep bedding and, finally, the introduction of intermediate disinfection of teat cups with peracetic acid to prevent the spread of infection to other healthy individuals. The eradication process lasted approximately three years and required the removal of 139 cows from the farm. The corrective and preventive measures described in this case report provide guidance to farmers on how to successfully deal with protothecal mastitis on farms

Mycobacteria in the animal’s environment in the Czech Republic

The “atypical mycobacteria ” are widely distributed in the natural environment and can produce infection in farm and wild animals bred in captivity. The objective of the study was to analyze the variety of mycobacterial species in the environment of breeding facilities, tanks and aquariums, as well as in samples of peat used as a feed supplement in the Czech Republic over the 2003-2004 period. A total of 1389 samples from environment were examined, collected from 29 sites throughout the Czech Republic. The samples were decontaminated and cultured at 25 °C and 37 °C in three culture media: Stonebrink’s medium, Herrold’s egg yolk medium and Sula’s medium. Mycobacterial isolates grown were identified by the PCR method and growth and biochemical tests. Of the 1389 environmental samples, mycobacteria were demonstrated by culture in 400 (28.8%) of them originating from different substances. In the samples of farm environment and in peat, mycobacteria were isolated in 185 of 1064 (17.4%) samples, and in 201 of 325 (61.8%) samples from aquarium and breeding tank environment. The results show significant difference between the findings from the stable environment (17.4%) and those from the aquarium environment (61.8%). A wide range of species was found in all constituents of the environment. The following species were most frequently isolated from the stable environment: M. avium (6.5%), M. fortuitum (3.2%), M. flavescens (3.2%), and the aquarium environment harboured most frequently M. fortuitum (13.9%), M. marinum (8.0%) and M. gordonae (4.5%). The results confirm the frequent occurrence of various mycobacterial species in the environment, predominantly in aquariums, some of which can produce infection in animals and in man following contact with the infected environment

First Evidence of the Presence of the Causative Agent of Caseous Lymphadenitis&mdash;Corynebacterium pseudotuberculosis in Dairy Products Produced from the Milk of Small Ruminants

This study focused on the detection and quantification of selected bacteria and on the presence of enterotoxin genes in milk and dairy products from sheep and goat farms in the Czech Republic using quantitative real-time PCR (qPCR) and multiplex PCR (PCR). The presence of Corynebacterium pseudotuberculosis (CP), Mycobacterium avium subsp. paratuberculosis (MAP), Listeria monocytogenes, Staphylococcus aureus, S. aureus enterotoxin genes and methicillin-resistant Staphylococcus aureus (MRSA) was determined in 18 milk samples, 28 fresh cheeses, 20 ripened cheeses and 14 yoghurts. The serological status of the herds in relation to CP and MAP was taken into account. The most frequently detected bacterium was S. aureus (48.8%), and subsequent PCR revealed 11 MRSA positive samples. The S. aureus enterotoxin genes seg, sei and sec were detected in two goat cheeses. Cheese samples showed a statistically higher risk of SA and MRSA occurrence. CP (8.8%) and MAP (13.8%) were detected by qPCR on two different seropositive farms. Cultivation of qPCR positive CP samples on agar plates supplemented with potassium tellurite showed the presence of viable bacterium. The results obtained confirmed the necessity of monitoring the infectious status of dairy animals and rapid diagnosis of bacterial pathogens in milk and dairy products

Antibiotic Susceptibility, Resistance Gene Determinants and Corresponding Genomic Regions in <i>Lactobacillus amylovorus</i> Isolates Derived from Wild Boars and Domestic Pigs

Restrictions on the use of antibiotics in pigs lead to the continuous search for new probiotics serving as an alternative to antibiotics. One of the key parameters for probiotic bacteria selection is the absence of horizontally transmissible resistance genes. The aim of our study was to determine antibiotic susceptibility profiles in 28 Lactobacillus amylovorus isolates derived from the digestive tract of wild boars and farm pigs by means of the broth microdilution method and whole genome sequencing (WGS). We revealed genetic resistance determinants and examined sequences flanking resistance genes in these strains. Our findings indicate that L. amylovorus strains from domestic pigs are predominantly resistant to tetracycline, erythromycin and ampicillin. WGS analysis of horizontally transmissible genes revealed only three genetic determinants (tetW, ermB and aadE) of which all tetW and ermB genes were present only in strains derived from domestic pigs. Sequence analysis of coding sequences (CDS) in the neighborhood of the tetW gene revealed the presence of site-specific recombinase (xerC/D), site-specific DNA recombinase (spoIVCA) or DNA-binding transcriptional regulator (xre), usually directly downstream of the tetW gene. In the case of ermB, CDS for omega transcriptional repressor or mobilization protein were detected upstream of the ermB gene

Mycobacterium avium subsp: Paratuberculosis sheep strains isolated from Cyprus sheep and Goats

Paratuberculosis, caused by Mycobacterium avium subsp. paratuberculosis (Map), is a chronic incurable infection of intestinal tract of animals. Molecular characterization of Map isolates classifies them into two major groups, 'Cattle' or Type II and 'Sheep' or Type I/III with a different phenotype, epidemiology, virulence and pathogenesis. The aim of this study was to examine 192 Map ELISA-positive sheep and goats from Cyprus using faecal culture and genotype Map isolates using IS1311 PCR and restriction endonuclease analysis (IS1311 PCR-REA) with HinfI restriction enzyme. Map was isolated from only four (4.6%) faecal samples out of 88 sheep and 15 (14.4%) faecal samples out of 104 goats. Genotyping of the isolates using IS1311 PCR-REA revealed that sheep and goat populations on the island are infected primarily by 'Sheep' strains. Only three Map isolates from goats originated from one farm were characterized as 'Cattle' strains

Prototheca Infections and Ecology from a One Health Perspective

International audiencePrototheca microalgae were only recognized as pathogens of both humans and animals in the 1960s; however, since then, these microbes have been drawing increasing interest in both human and veterinary medicine. The first human outbreak of protothecosis in a tertiary care chemotherapy ward in 2018 further highlighted the need to understand in more depth and detail their ecology, etiology, pathogenesis and routes of transmission between different hosts, environments and habitats from a One Health perspective. Protothecal infections have been reported in a growing number of cattle herds around the world in recent decades, and Prototheca has become an important bovine mastitis pathogen in certain countries and regions. The survival of Prototheca in the environment and its ability to spread in the herd pose a serious challenge to the management of infected dairy farms. Prevention of the disease is particularly important, as there is no effective and reliable treatment for it and the chances of self-healing are minimal. Therefore, the development of more effective drugs is needed for the treatment of human and animal protothecosis. The prudent use of antibiotics and their replacement by alternative or preventive measures, when possible, may further contribute to the control of protothecal infections