Evaluation of goat based ‘Indigenous vaccine’ against Bovine Johne’s Disease in endemically infected native cattle herds.

‘Indigenous vaccine’ prepared from ‘Indian Bison Type’ a native bio-type of Mycobacterium avium subspecies paratuberculosis strain ‘S5’ of goat origin (goat based) was evaluated in indigenous cattle herds located in gaushalas (cow shelters), endemic for Bovine Johne’s disease. Cows (893) were randomly divided into vaccinated (702 = 626 adults + 76 calves) and control (191 = 173 adults + 18 calves) groups. Response to vaccination was evaluated on the basis of health (mortality, morbidity), productivity (growth rate, reproductive performance, total milk yield), immunological parameters (LTT, ELISA titer), survivability of animals naturally infected with MAP, bacterimia (by specific blood PCR), sero-conversion (by indigenous ELISA) and status of shedding of MAP in feces (by microscopy) in the two groups before and after vaccination. Reduction in MAP shedding [to the extent of 100% in Herd A; and from 82.1% (0 DPV) to 10.7% (270 DPV) in Herd C] was the major finding in vaccinated cows. Whereas, the control group cows have shown no improvement. As the first indicator of vaccine efficacy, MAP bacilli disappeared from the blood circulation as early as 15 days post vaccination, however, peak titers were achieved around 90 DPV. Peak titers initially declined slightly but were maintained later throughout the study period. Control animals did not show any pattern in antibody titers. Mortality was low in vaccinated as compared to the control groups. Vaccination of endemically infected native cattle herds with inactivated whole-cell bacterin of novel ‘Indian Bison Type’ bio-type of goat origin strain ‘S5’ effectively restored health and productivity and reduced clinical BJD. Application of goat based ‘indigenous vaccine’ for therapeutic management of BJD in native cattle herds (gaushalas) is the first of its kind.

Evaluation of ‘cattle’ and ‘Indian Bison’ type antigens of Mycobacterium avium subspecies paratuberculosis for diagnosis of Bovine Johne’s Disease using ‘indigenous ELISA’ and AGPT .

Two antigens (‘cattle’ type and ‘Indian Bison’ type) of Mycobacterium avium subspecies paratuberculosis were evaluated for diagnosis of Johne’s disease (JD) in a gaushala (cattle herd). Of the 160 cows of Sahiwal and Hariana breeds screened, 81 (50.6%) tested positive in ELISA and 66 (41.8%) in AGPT test. Using the two antigens, 33.5% tested positive in both the tests while 41.1% tested negative. Exclusively, only 8.2% tested positive in ELISA while 17.1% tested positive in AGPT. Two antigens together detected 58.9% prevalence of MAP in the gaushala. Individually, indigenous ELISA using antigen from native source of MAP proved superior to AGPT in the diagnosis of JD in cows.

Obtención y evaluación de un derivado proteico purificado de una cepa argentina de Mycobacterium avium subsp. paratuberculosis / Production and evaluation of a purified protein derivative from an Argentine strain of Mycobacterium avium subsp. paratuberculosis (MAP)

Los derivados proteicos purificados (PPD) son mezclas antigénicas no definidas obtenidas de distintas micobacterias. Los PPD bovino (PPDb) y PPD aviar (PPDa) son los antígenos que se emplean para evaluar la respuesta inmunitaria celular en infecciones como tuberculosis y paratuberculosis en el bovino. El PPDa comercial se produce a partir de Mycobacterium avium subsp. avium, y no a partir de la subespecie paratuberculosis. En este trabajo se seleccionó una cepa local de Mycobacterium avium subsp. paratuberculosis cuyo patrón molecular por RFLP es el más frecuente entre los aislamientos de nuestro país que han sido estudiados, y a partir de esta, se obtuvo un derivado proteico purificado: PPDj-IB. Se emplearon tanto el PPDa comercial como el PPDj-IB como antígenos en la prueba de liberación de gamma-interferón en animales de un tambo con paratuberculosis y en animales control. Aun cuando ambos PPD fueron capaces de estimular diferencialmente la liberación de la citoquina en el tambo infectado (respecto de los tambos control), no hubo diferencias significativas en los niveles de estimulación producidos y solo dos animales fueron positivos mediante el empleo de PPDj-IB. A partir del análisis por Western blot se demostró que el contenido de lipoarabinomano y del antígeno Apa/ModD era distinto en los PDD evaluados. Estas diferencias podrían explicar, en parte, las diferencias en los niveles de estimulación en términos individuales. Si bien el empleo de PPDj-IB no mejoró significativamente los resultados de la prueba de liberación de ?IFN, es importante destacar que se logró producir en el laboratorio un PPD apto para su empleo en ensayos in vitro.

Purified Protein Derivatives (PPDs) are non-defined antigens prepared from mycobacteria cultures. They are usually employed to evaluate the specific cellular immune response both in animals and humans. Bovine and avian PPDs are usually employed as antigens in mycobacterial infections such as tuberculosis and paratuberculosis. Nevertheless, PPD from Mycobacterium avium subsp. paratuberculosis, (PPDj) is neither commonly used nor frequently available. However, PPD from Mycobacterium avium subsp. avium is in fact used. We aimed to obtain and evaluate the performance of a PPDj from a local isolate of MAP using the ãInterferon-release assay. The stimulation of ãInterferon-release was significantly different between infected and control cattle when this antigen, named PPDj-IB, was used. Stimulation in the infected animals was similar with both antigens (PPDa and PPDj-IB). However, some animals were positively stimulated with PPDj-IB and not with PPDa. We demonstrated by Western blot that two antigenic molecules, lipoarabinoman and APA/ModD antigen were differentially represented in both PPDs. This could explain the difference in stimulation induction of ?IFN observed at individual level. Although PPDj-IB could not improve PPDa performance, we could easily produce an effective purified protein derivative for in vitro assays.

[Cloning, sequencing and expression of HSP70 c-terminal domain in Mycobacterium avium subsp. paratuberculosis]

Heat shock proteins [HSPs] have been shown to act as an adjuvant when co-administered with different antigens, especially tumor antigens or antigens from infectious agents. C-terminal domain of Mycobacterium tuberculosis heat shock protein 70 [Hsp70], when fused to peptide antigens, provides a unique structure that is able to induce potent immune responses. In this study, aneukaryotic expression vector pEGFP-N1, containing C-terminal domain of Mycobacterium paratuberculosis HSP 70, Green Fluorescent Protein [GFP] gene in the plasmid construct, was designed for use as a reporter. With GFP system, expression of the target protein was evaluated in the cell culture. The nucleotide sequence of the cloned gene was revealed by sequencing. The protein expression of designed plasmid was also proved by reverse transcriptase polymerase chain reaction [RT-PCR]. Our eukaryotic expression vector [pEGFP-N1 -hsp70 c-terminal] was successfully constructed and HSP70 c-terminal domain protein was expressed effectively. The current experiment, as a basis for a new DNAvaccine design, can be used for the future studies on reverse vaccinology

Comparative antibody response of five recombinant antigens in related to bacterial shedding levels and development of serological diagnosis based on 35 kDa antigen for Mycobacterium avium subsp. paratuberculosis

Eighty-five complex (85A, 85B and 85C), 35-kDa and superoxide dismutase (SOD) were cloned, expressed and purified as antigens in an enzyme-linked immunosorbent assay (ELISA) to compare the serological reactivity of cows with different shedding levels of Mycobacterium avium subsp. paratuberculosis (MPT). Antibody responses to all recombinant antigens positively increased depending on shedding levels. In particular, antibody responses to the 35 kDa were higher than those to the others in all shedder groups. Also, the mean of O. D. values among Ag 85 complex, 85B showed slightly higher response than others with high sensitivity and specificity in all shedder groups. In receiver operating characteristic (ROC) curve analysis, the result of 35 kDa ELISA yielded an area under the curve value of 0.945 (95% confidence interval = 0.895 . 0.996), which indicated that this 35 kDa is more accurate indicator of MPT infection than other antigens. At the cut-off point recommended by the ROC curve analysis, the sensitivity and specificity of 35 kDa ELISA were higher than those of other antigens with 93.3% and 86.4%, respectively. Finally, a commercially available ELISA kit was used to clarify 200 positive and 200 negative sera. We then re-tested these serum samples with our ELISA test using the 35-kDa antigens. 35 kDa ELISA and commercial kit showed almost similar results in ROC curve analysis even though two of positive sera in commercial kit were negative in 35 kDa ELISA. The sera, which showed difference in the comparison with commercial ELISA kit, they also did not react with 35 kDa in Western blot. These results suggest that a 35-kDa based ELISA can be useful for detecting MPT infection.

Respueta humoral a micobacterias en pacientes con enfermedad de Crohn / Humoral response to mycobacterium in patients with Crohn disease

El reciente aislamiento de Mycobacterium paratuberculosis de lesiones de pacientes con enfermedad de Crohn (EC) reavivó el interés en el posible origen micobacteriano de esta enfermedad. Sin embargo, las evidencias inmunológicas acumuladas en favor de esta hipótesis son poco sólidas. La respuestaespecífica en la EC podría estar enmascarada por el amplio cruzamiento antigénico que existe entre microbacterias. En este estudio se aplico un procedimiento propuesto para develar la presencia de anticuerpos anti-M. paratuberculosis en la enfermedad de Johne bovina: la absorción de los anticuerpos con reactividad cruzada mediante la preincubación de los sueros con M. phlei. Se cuantificó por enzimoinmunoensayo IgG anti-M. paratuberculosis en 90 muestras de suero de 17 pacientes con EC, 23 con colitis ulcerosa (CU) y 14 con otras patologías intestinales (OP). Muestras de 86 individuos sanos, con tuberculosis, microbacteriosis o micosis sirvieron como control. Se comparó los resultados con los obtenidos con antígenos de M. avium y M. tuberculosis. Se observó una discreta reactividad humoral a micobacterias en pacientes con EC, Cu y OP. Las alteraciones fueron de muy escasa magnitud y frecuencia en relación con las observadas en pacientes con tuberculosis, micobacteriosis y micosis. La absorción de los sueros no develó una presunta respuesta específica en la EC. Tampoco se detectaron elevaciones en los niveles de anticuerpos de pacientes analizados periodicamente. Estos datos no agregan evidencia sólida a la hipótesis del origen micobacteriano de la EC