Detection of wide genetic diversity and several novel strains among non-avium nontuberculous mycobacteria isolated from farmed and wild animals in Hungary.

AIMS: Besides Mycobacterium avium numerous nontuberculous Mycobacterium (NTM) species exist, which pose constant health risk to both humans and animals. The aim of our study was to identify non-avium NTM isolates from veterinary origin in Hungary, and to detect the occurrence of rifampicin resistance among them. METHODS AND RESULTS: Two hundred and twenty-five strains isolated between 2006 and 2013 from domestic and wild animals and veterinary important samples were identified on the basis of partial DNA sequences of different structural or coding genes, besides commercial kits and multiplex PCR. From 14 different sources, 28 NTM strains and 8 hitherto unidentified strain types were detected. Mycobacterium nonchromogenicum was the most frequently occurring strain (25·78%). Besides, new hosts and mycobacteria-related pathological symptoms were detected. Noticeable rifampicin resistance (42·76%) was found among 159 strains from six different host species. Furthermore, we described the problematics of strain-misidentifications using commercial kits. CONCLUSIONS: Our study identified the most common non-avium NTM strains in Hungary, and provided account of their occurrence, host range, and pathogenicity. The detected high rifampicin resistance among the strains isolated mainly from fallow and red deer clearly shows that more attention should be paid to the examination of wild animals especially to those ones which may have contact or shared territory with farmed animals. SIGNIFICANCE AND IMPACT OF THE STUDY: In domestic animal husbandry the maintenance of tuberculosis free status is of primary importance. As immunological cross-reactions due to NTM hamper the diagnosis of bovine tuberculosis, the precise identification of NTM strains would be essential in the veterinary diagnostics, especially for potentially zoonotic strains. This is the first study investigating the strain diversity of non-avium NTM in Hungary.

Molecular analysis and MIRU-VNTR typing of Mycobacterium avium subsp. paratuberculosis strains from various sources.

AIMS: Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of Johne's disease. Genotypic discrimination of MAP isolates is pivotal to epidemiological studies requisite for revealing infection sources and disease transmission. This study was undertaken to determine the genetic diversity of MAP strains from diverse sources. METHODS AND RESULTS: Five hundred and sixty-nine MAP isolates were collected during an 8-year period from nine animal species, originating from seven European countries, including the whole geographic region of Hungary. Isolates were classified into cattle type and sheep type, and 515 strains were included in mycobacterial interspersed repetitive units-variable-number tandem repeat analysis. CONCLUSIONS: The same genotype was found in different host species cohabiting on the same property, demonstrating interspecies transmission. Detecting identical patterns in numerous related animals underlines the importance of vertical transmission. The revealed 15 genotypes expose relatively low strain diversity and indicate the need of an improved typing system that provides higher resolution in the case of this subspecies. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results demonstrate the circulation and transmission of different MAP strain types among individuals, herds and even wildlife reservoirs in Hungary and other European countries; correlation between production type or breed and MAP genotype is hypothesized.

Endocrine aspects in pathogenesis of mastitis in postpartum dairy cows.

In well-managed dairy herds some environmental pathogens including Gram-negative (GN) strains (E. coli and others) have been recognized recently as the predominant causative microbes of mastitis in the peri-parturient period. In early weeks of lactation hyperketonaemia may predispose the high-producing cows for GN mastitis. In GN mastitis cytokines, eicosanoids and oxygen radicals are released, which are responsible for the local and systemic symptoms. Experimental administration of endotoxin induces a complex endocrine cascade. Similar changes in plasma levels of cortisol, insulin, insulin-like growth factor-I and thyroid hormones are seen also in severe cases of GN mastitis. However, leptin is not responsible for the anorexia associated with severe mastitis in ruminants. Mastitis can postpone the resumption of ovarian cyclic activity in dairy cows when its outbreak occurs between days 15 and 28 after calving (at the expected time of first ovulation). In cyclic cows severe cases of GN mastitis can induce premature luteolysis or prolong the follicular phase.

Review of the microbiological, pathological, and clinical aspects of bovine mastitis caused by the alga Prototheca zopfii.

The mastitis caused by P. zopfii alga is a disease of high-producing, machine-milked dairy cows. It occurs worldwide in tropical and temperate climatic areas, and mostly appears sporadically in a therapy-resistant form. However, in poorly managed dairy herds it may be endemic, causing serious economic losses as a result of decreased milk quality and quantity and culling of infected animals. The biological properties of this pathogenic alga, the laboratory methods available for its isolation and identification, the pathological and clinical features of this form of mastitis, and the principles of its control are reviewed in this paper.

Prototheca zopfii mastitis in dairy herds under continental climatic conditions.

In the last 2 years 223 cases of bovine mastitis caused by Prototheca zopfii infection were identified in 32 large-scale dairy herds. All of these farms were in Hungary, which has a continental type, temperate zone climate. Both the sporadic and epidemic forms of P. zopfii mastitis were observed. All the herds affected by the epidemic form had poor hygienic conditions and suffered from several managerial faults, but no specific predisposing factors could be identified. In almost all of the cases, the type II variant of this pathogen was isolated; however, the type III variant was isolated from three cows. The cows had a higher chance of new infection in the early weeks of lactation and in the summer. The P. zopfii infection usually resulted in a chronic subclinical, or mild clinical, inflammatory process in the udder, and was followed by a dramatic loss in milk production and a permanent increase in somatic cell count. The histopathological findings could be characterized as a progressive interstitial mastitis associated with alveolar atrophy. The self-recovery rate was very low.

Endocrine and reproductive consequences of certain endotoxin-mediated diseases in farm mammals: a review.

After giving an overview of the general pathology of endotoxin-mediated diseases, the authors summarise the endotoxin-induced endocrine changes and their clinical consequences, with particular regard to reproduction. The consequences of temporary activation of the cyclooxygenase-2 and lipoxygenase enzyme systems resulting in elevated release of various prostanoids are discussed in cyclic and pregnant ruminants, sows and mares. The clinical failures attributable to increased glucocorticoid secretion as well as the endotoxin-induced changes in thyroid function and in peripheral level of some other hormones (prolactin, growth hormone and insulin-like growth factor 1) are also reviewed.

Bacteriological recovery after intramuscular or intracisternal spiramycin-based drying-off therapy.

Systemic (intramuscular, i.m.) vs. local (intracisternal, IC) routes of spiramycin-based drying-off therapy were compared for efficacy on 65 Staphylococcus aureus infected udder quarters of 38 dairy cows. Single-dose (30,000 IU/kg) i.m. treatment (single i.m. group) resulted in a similarly low bacteriological recovery rate (14%) as seen in the untreated controls (18%). I.m. treatment (30,000 IU/kg) on 4 consecutive days (4 i.m. group) resulted in significantly higher quarter-based recovery rates than that in the single i.m. group. The bacteriological recovery rates obtained in the intracisternal and 4 i.m. groups were quite similar but remained below 50%. Based on these findings as well as on the high cost of the repeated intramuscular treatment regime there is no reason to give extra preference to the systemic application of spiramycin at drying off in the practice.

Diagnostic value of certain mastitis markers in following up the clinical and bacteriological changes in pharmacotherapeutic studies.

Trends of certain mastitis markers were studied in udder quarters (n = 201) showing clinical symptoms of acute mastitis. Besides the clinical examination, before the first treatment (baseline sample), and about 3 weeks later, 17 to 24 days following the last treatment (control sample) milk samples were collected for bacteriological identification of the mastitis pathogens and for the determination of certain inflammatory markers: somatic cell count (SCC), N-acetyl-beta-D-glucosaminidase (NAGase) and alpha 1-antitrypsin (ATR) activities, as well as bovine serum albumin (BSA) and chloride (Cl-) concentrations. Based upon the clinical and bacteriological status as well as the SCC recorded at the control investigations, 6 groups were established (recovered, latently infected, subclinical mastitis: bacteriologically positive and negative, as well as clinical mastitis: bacteriologically positive and negative). As compared to the baseline samples, all parameters decreased in the case of recovered udder quarters, as well as in those with abated latent infection or subclinical mastitis at the time of control examination. Comparing the control samples of the different categories, characteristic differences were found in NAGase activity, indicating the grade of cytodamaging effect of mastitis. Of the other markers, ATR and Cl- proved to be more adequate for the differentiation than BSA. It can be concluded that, in addition to SCC, first of all NAGase can be recommended for use as an inflammatory parameter in pharmacodynamic studies. Besides these two parameters, ATR and Cl- can also be chosen as a possible third marker.

The photorefractoriness in domestic goose: effect of gonads and thyroid on the development of postbreeding prolactinemia.

Blood samples were taken from adult male and female geese, and from gonadectomized (GX), thyroidectomized (TX) and gonadectomized+thyroidectomized (GX+TX) ones during the reproduction peak period (March 16), at the beginning of photorefractoriness (June 14), in the second half of the photorefractory period (August 14), and at the beginning of the postrefractory period (October 2). Surgeries were carried out at the age of 10-13 weeks. The birds were kept under natural light conditions. From the blood plasma prolactin (PRL), luteinizing hormone (LH), testosterone (T), progesterone (P4), 17 beta-oestradiol (E2) as well as thyroxine (T4) and triiodo-tironine (T3) were determined by RIA methods. At the beginning of photorefractoriness in intact geese the LH and E2 levels significantly decrease, relative to sexually active period, whereas the P4 remains at a high level. In ganders the LH shows only a slight decrease but the T level is significantly lower than in spring. The PRL, T4 and T3 levels increase after reproduction and give a peak value in both sexes. In both GX ganders and geese decreased T, P4 and T3 levels are observable and the PRL is decreased in females, and the LH is increased in both sexes. Gonadectomy does not influence the E2 in females, the PRL in males and the T4 in both sexes. In TX birds the PRL is higher in March and lower in June than the control level, but these changes are significant only in females. In TX females the P4 level is lower during reproduction and at the beginning of photorefractoriness. The T and E2 levels do not change during the photorefractoriness. In the second half of photorefractoriness a low PRL and P4 level, an increasing LH, T and medium high T4 and T3 levels characterized the intact male and female geese. In GX animals an increase of LH levels is occurred in both sexes. The T4 is higher in castrated-, and lower in ovarectomized geese. In TX birds the P4 is higher than in controls, but the difference is significant only in males. The levels of PRL, LH, T and E2 remain unchanged in TX animals. At the beginning of the postrefractory phase the T (in males) and the P4 and the T4 level increase in both sexes. The PRL and LH show a low value. In GX animals the high LH level refer to the increased sensitivity of hypothalamo-gonadotropic system, because of the absence of negative feed-back of sexual steroids.4+ in both sexes and a high thyroid hormone level and a transitional slight reactivation of gonadotropic-gonadal system occur then.