The importance of fungal infections in both human and animals has increased over the last decades. This article represents an overview of the different categories of fungal infections that can be encountered in animals originating from environmental sources without transmission to humans. In addition, the endemic infections with indirect transmission from the environment, the zoophilic fungal pathogens with near-direct transmission, the zoonotic fungi that can be directly transmitted from animals to humans, mycotoxicoses and antifungal resistance in animals will also be discussed. Opportunistic mycoses are responsible for a wide range of diseases from localized infections to fatal disseminated diseases, such as aspergillosis, mucormycosis, candidiasis, cryptococcosis and infections caused by melanized fungi. The amphibian fungal disease chytridiomycosis and the Bat White-nose syndrome are due to obligatory fungal pathogens. Zoonotic agents are naturally transmitted from vertebrate animals to humans and vice versa. The list of zoonotic fungal agents is limited but some species, like Microsporum canis and Sporothrix brasiliensis from cats, have a strong public health impact. Mycotoxins are defined as the chemicals of fungal origin being toxic for warm-blooded vertebrates. Intoxications by aflatoxins and ochratoxins represent a threat for both human and animal health. Resistance to antifungals can occur in different animal species that receive these drugs, although the true epidemiology of resistance in animals is unknown, and options to treat infections caused by resistant infections are limited.
Escherichia coli is a major etiological agent of intra-mammary infections (IMI) in cows, leading to acute mastitis and causing great economic losses in dairy production worldwide. Particular strains cause persistent IMI, leading to recurrent mastitis. Virulence factors of mammary pathogenic E. coli (MPEC) involved pathogenesis of mastitis as well as those differentiating strains causing acute or persistent mastitis are largely unknown. This study aimed to identify virulence markers in MPEC through whole genome and phenome comparative analysis. MPEC strains causing acute (VL2874 and P4) or persistent (VL2732) mastitis were compared to an environmental strain (K71) and to the genomes of strains representing different E. coli pathotypes. Intra-mammary challenge in mice confirmed experimentally that the strains studied here have different pathogenic potential, and that the environmental strain K71 is non-pathogenic in the mammary gland. Analysis of whole genome sequences and predicted proteomes revealed high similarity among MPEC, whereas MPEC significantly differed from the non-mammary pathogenic strain K71, and from E. coli genomes from other pathotypes. Functional features identified in MPEC genomes and lacking in the non-mammary pathogenic strain were associated with synthesis of lipopolysaccharide and other membrane antigens, ferric-dicitrate iron acquisition and sugars metabolism. Features associated with cytotoxicity or intra-cellular survival were found specifically in the genomes of strains from severe and acute (VL2874) or persistent (VL2732) mastitis, respectively. MPEC genomes were relatively similar to strain K-12, which was subsequently shown here to be possibly pathogenic in the mammary gland. Phenome analysis showed that the persistent MPEC was the most versatile in terms of nutrients metabolized and acute MPEC the least. Among phenotypes unique to MPEC compared to the non-mammary pathogenic strain were uric acid and D-serine metabolism. This study reveals virulence factors and phenotypic characteristics of MPEC that may play a role in pathogenesis of E. coli mastitis.
Morbidity due to Corynebacterium pseudotuberculosis infection occurred in 29 dairy herds in Israel during 1989 to 1995. The disease occurred sporadically in 17 of the herds with a morbidity of up to 5 per cent, and was epidemic in 12, with a morbidity of 5 to 35 per cent. Cutaneous abscesses were diagnosed in 609 animals. Young cattle appeared to be less susceptible to the disease than older cows. Beef cattle herds were not affected. The disease appeared in the cutaneous form in 92.5 per cent of cases, the cutaneous and mastitic form in 5.9 per cent and the cutaneous and visceral form in 1.6 per cent. The cutaneous form appeared as deep subcutaneous abscesses on various parts of the body, with granulating ulcers exuding pus and blood. In 10 of the herds, C pseudotuberculosis was isolated from 33 mastitic cows which also had cutaneous lesions. The visceral form of the disease was detected when severely affected animals were slaughtered. In 23 of the herds, the disease occurred during the spring and summer dry season, from March to October; the highest prevalence was in the semi-arid Negev region. In 25 herds, the infection lasted for up to five months. The skin lesions on individual cows healed on average in 23.4 days, after either local or parenteral treatment. No significant difference was observed between the effect of systemic antibiotic treatment and local antiseptic treatment. One hundred and two (16.7 per cent) severely affected animals were culled. There was a decrease in milk production and large increases in somatic cell counts in the 12 herds in which the disease was epidemic. None of the strains of isolated C pseudotuberculosis reduced nitrate.
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