Bovine TB infection status in cattle in Great Britain in 2015.

This report, provided by the APHA, presents the key descriptive epidemiological parameters of bovine TB in cattle in Great Britain from January 1 to December 31, 2015, providing summary information on the epidemic, including key statistics and epidemiological parameters as presented in the annual surveillance report for Great Britain, with supporting detail from specific reports for England and Wales. It updates the previous annual summaries for 2012 to 2014, also published in Veterinary Record.

Bovine TB surveillance in Great Britain in 2014.

This report, provided by the APHA, summarises the key descriptive epidemiological parameters of bovine TB in cattle in Great Britain from January 1 to December 31, 2014. It summarises some of the temporal trends observed over a longer period and highlights some differences and similarities between Scotland, Wales and the three bovine TB risk areas of England. It updates the previous annual summaries for 2012 and 2013, also published inVeterinary Record(VR, June 14, 2014, vol 174, pp 600-604; March 28, 2015, vol 176, pp 326-330).

Bovine TB infection status in cattle in Great Britain in 2013.

This report, provided by the APHA, summarises the infection status of bovine TB in cattle in Great Britain from January 1 to December 31, 2013 and describes some of the temporal trends observed over a longer period. It updates the previous annual summary for 2012, also published in Veterinary Record (VR, June 14, 2014, vol 174, pp 600-604).

Bovine TB infection status in cattle in Great Britain in 2012.

This report, provided by the AHVLA, summarises the infection status of bovine tuberculosis (TB) in cattle in Great Britain from January 1 to December 31, 2012 and describes some of the temporal trends observed over a longer period. The AHVLA intends to produce similar reports for future years to provide a concise summary of how the situation is developing.

The phylogeny and population structure of Mycobacterium bovis in the British Isles.

To further understand the epidemic of bovine tuberculosis in Great Britain, Northern Ireland and the Republic of Ireland, we identified 16 mutations that are phylogenetically informative for Mycobacterium bovis strains from these regions. We determined the status of these mutations among a collection of 501 strains representing the molecular diversity found in these three regions of the British Isles. The resulting linear phylogenies from each region were concordant, showing that the same lineage of M. bovis was present. The dominance of this lineage is unique within Europe, and suggests that in the past the populations were homogenous. Comparison of approximately 500 strains isolated in 2005 from each region by spoligotype and 5 locus VNTR profiling, revealed distinct differences in the genotype frequencies and sub-lineage makeup between each region. We concluded that whilst each region shared the same major phylogenetic lineage of M. bovis, more recent evolution had resulted in the development of region-specific populations. Regional differences in the M. bovis populations suggest that it may be possible to identify the movement of strains from one region to another.

Comparative pathology of the natural infections by Mycobacterium bovis and by Mycobacterium caprae in wild boar (Sus scrofa).

The potential role of wild animals in the maintenance and spread of tuberculosis (TB) infection in domestic livestock is of particular importance in countries where eradication programs have substantially reduced the incidence of bovine tuberculosis but sporadic outbreaks still occur. Mycobacterium bovis is the agent mainly isolated in wildlife in Spain, but recently, infections by Mycobacterium caprae have increased substantially. In this study, we have analysed 43 mandibular lymph nodes samples containing TB-like lesions from 43 hunted wild boar from Madrid and Extremadura (central and south-western regions of Spain). After isolation, identification and typing of Mycobacterium tuberculosis complex isolates, we found that 23 mandibular lymph nodes involved M. caprae infections and 20 M. bovis. The lesions were compared for histopathology (different granuloma stage and number of multinucleated giant cells (MNGCs)), and acid-fast bacilli (AFBs) were quantified in the Ziehl-Neelsen-stained slides. Granulomas produced by M. caprae showed more stage IV granulomas, more MNGCs and higher AFBs counts than those induced by M. bovis. In conclusion, lesions caused by M. caprae would be more prone to the excretion of bacilli, and infected animals result as a high-risk source of infection for other animals.

Histological and immunohistochemical characterisation of Mycobacterium bovis induced granulomas in naturally infected fallow deer (Dama dama).

Mycobacterium bovis infections in fallow deer have been reported in different countries and play an important role in the epidemiology of bovine tuberculosis (bTB), together with other deer species. There is little knowledge of the pathogenesis of bTB in fallow deer. The aim of this study was to perform a histopathological characterisation of the granulomas induced by M. bovis in this species and the immunohistochemical distribution of different cell subsets (CD3+, CD79+, macrophages) and chemical mediators (iNOS, TNF-α, IFN-γ) in the different developmental stages of granulomas. Stage I/II granulomas showed a marked presence of macrophages (MAC387+) expressing high iNOS levels while stage III/IV granulomas showed a decrease in the number of these cells forming a rim surrounding the necrotic foci. This was correlated with the presence of IFN-γ expressing cell counts, much higher in stage I/II than in stage III/IV. The number of B cells increased alongside the developmental stage of the granuloma, and interestingly the expression of TNF-α was very low in all the stages. This characterisation of the lesions and the local immune response may be helpful as basic knowledge in the attempts to increase the vaccine efficacy as well as for disease severity evaluation and for the development of improved diagnostic tools. Immunohistochemical methods using several commercial antibodies in fallow deer tissues are described.

Mechanisms of alloimmunization and subsequent bone marrow transplantation rejection induced by platelet transfusion in a murine model.

For many nonmalignant hematological disorders, HLA-matched bone marrow transplantation (BMT) is curative. However, due to lack of neoplasia, the toxicity of stringent conditioning regimens is difficult to justify, and reduced intensity conditioning is used. Unfortunately, current reduced intensity regimens have high rates of BMT rejection. We have recently reported in a murine model that mHAs on transfused platelet products induce subsequent BMT rejection. Most nonmalignant hematological disorders require transfusion support prior to BMT and the rate of BMT rejection in humans correlates with the number of transfusions given. Herein, we perform a mechanistic analysis of platelet transfusion-induced BMT rejection and report that unlike exposure to alloantigens during transplantation, platelet transfusion primes alloimmunity but does not stimulate full effector function. Subsequent BMT is itself an additional and distinct immunizing event, which does not induce rejection without antecedent priming from transfusion. Both CD4(+) and CD8(+) T cells are required for priming during platelet transfusion, but only CD8(+) T cells are required for BMT rejection. In neither case are antibodies required for rejection to occur.

Mycobacterium microti infection in two meerkats (Suricata suricatta).

Mycobacterium microti is a member of the Mycobacterium tuberculosis complex (MTC). M. microti is generally considered a pathogen of small rodents, although sporadic infections in a range of other mammals, including domestic animals and man, have been reported. While many human infections have been associated with immunosuppression, an increasing number of cases are being reported in immunocompetent patients. Two cases of M. microti infection in meerkats (Suricata suricatta) are reported. These are the first cases of mycobacterial disease to be described in meerkats outside Africa.

Exploring the use of molecular epidemiology to track bovine tuberculosis in Nigeria: an overview from 2002 to 2004.

Tuberculosis remains a major public health problem in Nigeria. While human to human transmission of Mycobacterium tuberculosis is clearly of major importance in driving the tuberculosis epidemic in Nigeria, the impact of Mycobacterium bovis transmission from infected cattle is largely unknown. Molecular epidemiology of M. bovis in Nigeria will increase our understanding of this endemic disease and provide tools to assess cattle-to-human transmission. Between 2002 and 2004, molecular techniques including spoligotyping, variable number of tandem repeats (VNTR) typing and deletion typing were used to track and analyze a sample of strains of the M. tuberculosis complex circulating in the cattle population in Ibadan, Southwestern Nigeria. In all, 180 isolates were typed with a view to elucidating epidemiological information on circulating strains, occurrence of transborder transmission and molecular diversity of the M. bovis strains. Results obtained showed that 99% (178/180) of the isolates were M. bovis, while the remaining were M. tuberculosis and M. africanum. In all, strains of M. bovis had 34 different spoligotypes: strains with spoligotype pattern SB0944 (as designated by www.mbovis.org) were the most common (46% of strains). This molecular type is also common in countries neighbouring Nigeria. Strains with this spoligotype pattern could be further divided into 40 different VNTR types. This analysis shows the value of simple molecular epidemiological techniques applied to strains of M. bovis and suggests that further epidemiological studies will shed more light on the transmission dynamics of bovine tuberculosis locally and across neighbouring African countries.

MHC II on transfused murine blood is not required for alloimmunization against MHC I.

BACKGROUND AND OBJECTIVES: Transfusion of allogeneic platelet products can result in antibodies against donor major histocompatibility complex (MHC) I antigens, leading to a refractory state to subsequent platelet transfusions. However, there is disagreement in the field regarding the molecular mechanisms of humoral alloimmunization. One hypothesis states that donor MHC II is a requirement for alloimmunization. However, other studies have suggested that donor MHC I is alone sufficient and MHC II is not required. MATERIALS AND METHODS: We utilized a mouse model of anti-MHC I alloimmunization to transfused blood, which employed donors with a complete deletion of all MHC II genes. BALB/c (H-2(d)) recipients were transfused with blood from either C57BL/6 (H-2(b)) or MHC II null donors on a C57BL/6 background. Anti-MHC I alloimmunization was monitored by indirect immunofluorescence. RESULTS: Recipients of either wild type or MHC II null blood produced equivalent humoral responses against donor MHC I antigens. However, there was variation in the relative amounts of IgG subclasses. CONCLUSION: These data reject the hypothesis that donor MHC II expression is required for alloimmunization to MHC I antigens.

Mycobacterium microti: More diverse than previously thought.

Mycobacterium microti is a member of the Mycobacterium tuberculosis complex of bacteria. This species was originally identified as a pathogen of small rodents and shrews and was associated with limited diversity and a much reduced spoligotype pattern. More recently, specific deletions of chromosomal DNA have been shown to define this group of organisms, which can be identified by the absence of chromosomal region RD1(mic). We describe here the molecular characteristics of 141 strains of the Mycobacterium tuberculosis complex isolated in Great Britain over a 14-year period. All strains have characteristic loss of some spoligotype spacers and characteristic alleles at the ETR-E and ETR-F variable-number tandem-repeat (VNTR) loci, and a sample of these strains was deleted for regions RD7, RD9, and RD1(mic) but intact for regions RD4 and RD12. We therefore identified these strains as M. microti and show that they have much more diverse spoligotype patterns and VNTR types than previously thought. The most common source of these strains was domestic cats, and we show that the molecular types of M. microti are geographically localized in the same way that molecular types of Mycobacterium bovis are geographically localized in cattle in the United Kingdom. We describe the pathology of M. microti infection in cats and suggest that the feline disease is a spillover from a disease maintained in an unknown wild mammal, probably field voles. The location of the cats with M. microti infection suggests that they do not overlap geographically with the strains of Mycobacterium bovis in Great Britain.

Human and canine pulmonary Mycobacterium bovis infection in the same household: re-emergence of an old zoonotic threat?

Bovine tuberculosis (bTB), caused by Mycobacterium bovis, remains a serious animal health problem in the UK, despite longstanding statutory surveillance and control measures. Endemic infection in the Eurasian badger population is thought to complicate bTB eradication efforts. Sporadic cases of M bovis infection have also been reported in domestic animals other than cattle. Human M bovis infection is extremely rare in the native UK population in the absence of unpasteurised milk consumption or residence abroad. Here, pulmonary TB infection in a UK born female and her pet dog is described, caused by an identical strain of M bovis. Latent TB infection was also identified in a household contact. The potential routes of infection and implications of this case are discussed.

Camel tuberculosis--a case report.

An adult male dromedary bull was diagnosed with pulmonary tuberculosis (Tb). The dromedary was severely emaciated and died 2 months after the onset of the disease. It exhibited typical Tb lesions in both lungs and lung lymph nodes. A guinea pig inoculated with lung tissue from theTb camel died after 3 weeks from typical Tb. Mycobacteria were isolated from the dromedary's lung and lung lymph nodes and also from different organs of the guinea pig. The microorganism was identified as member of the antelope clade of the Mycobacterium tuberculosis complex.

Response of HIV-infected patients with asymptomatic syphilis to intensive intramuscular therapy with ceftriaxone or procaine penicillin.

The objective of this prospective pilot study was to evaluate the response of HIV-infected patients with asymptomatic syphilis to one of two intensive antibiotic treatment regimens. Thirty-one HIV-infected patients with serum rapid plasma reagin titre > or =1:4 and no clinical findings of syphilis were randomized to receive daily intramuscular injections of ceftriaxone or procaine penicillin (plus oral probenecid) for 15 days; 24 returned for follow-up study. Seven of 10 (70%) procaine penicillin-treated patients and 10 of 14 (71%) ceftriaxone-treated patients had a > or =4-fold decline in RPR (P=0.94); two penicillin-treated and one ceftriaxone-treated patient relapsed. Two patients failed ceftriaxone therapy. Three penicillin-treated, and two ceftriaxone-treated patients were serofast. Serological responses were similar in those patients with and without asymptomatic neurosyphilis. There was no difference in the serologic response to daily treatment with ceftriaxone vs that with procaine penicillin plus probenecid; both treatments were associated with comparatively high rates of serological non-response and relapse.

Population structure and evolutionary dynamics of pathogenic bacteria.

Evidence concerning the significance of recombination within natural bacterial populations has historically come from two main sources: multilocus enzyme electrophoresis (MLEE) and nucleotide sequence data. Here we discuss evidence from a third method, multilocus sequence typing (MLST), which is a development of MLEE based on nucleotide sequencing that combines the advantages of both approaches. MLST has confirmed both the existence of clones and the high rates of recombination for several bacterial pathogens. The data are consistent with "epidemic" population structures, where clones are superimposed upon a backdrop of frequent recombination, thus, in the short term, resisting the homogenising effect of recombination. The nature of the selective advantage of clones, however, and how this advantage relates to virulence are unclear. The current evidence also has broader implications concerning bacterial species definition, the management of antibiotic-resistant bacteria and the assessment of the dangers of releasing genetically modified organisms into the environment.