The effects of experimental Trypanosoma (trypanozoon) (brucei) evansi infection on the fertility of male goats

The effects on the fertility of small East African male goats of intravenous infection with Trypanosoma (t) (b) evansi were studied. Six infected bucks developed erratic, low but persistent parasitaemia, the packed cell volume dropped gradually but significantly (p<0.001) and they became emanciated. Half of these bucks developed clinical orchitis. Two bucks died of the disease during the experiment.Semen from all the infected bucks deteriorated in quality and quantity and those with clinical orchitis became totally aspermic. Spermatozoal abnormalities and the number of dead spermatozoa rose significantly. Later in the disease, the testicles of the infected bucks atrophied. Histologically, the testicles from the infected animals became devoid of spermatozoa, the testicular blood vessels contained microthrombi and there was infiltration of inflammatory cells. Subsequently, diffuse calcification set in, with calcium deposits obliterating most of the seminiferous vesicles and ducts and also the epididymal ducts.     

A Preliminary Comparative Study of a Dipstick Colloidal Dye Immunoassay and Two Antigen-detection ELISAs for Diagnosis of Trypanosoma evansi Infection in Cattle

A dipstick colloidal dye immunoassay (DIA) was developed for the field diagnosis of Trypanosoma evansi infection using affinity-purified polyclonal antibodies (PcAbs) and the monoclonal antibody (McAb) 8B9. PcAbs were adsorbed onto Palanil Red dye particles and used as dye reagents. Dipsticks were dotted with four different antibodies; normal rabbit and mouse IgGs as negative controls, and anti-T. evansi PcAb and McAb 8B9, which capture trypanosome antigens in the tested samples. Since the dye reagent bound to the captured antigens, the presence of coloured dots on the dipstick identified trypanosome infections. The sensitivity of the DIA was compared with two antigen detection ELISAs (Ag-ELISA); one was PcAb-based and the other was based on a combination of the same Mc- and PcAbs as were employed for the DIA. With a positive serum, the DIA detected trypanosomal antigen up to a dilution of 1:500 for both the PcAb and McAb dots, at which dilution the PcAb- and combination-based Ag-ELISA gave positive OD readings of 0.13 and 0.36, respectively. When 124 field sera were tested, circulating antigens were detected in 51 (41%) samples by the DIA, and 76 (61%) and 49 (40%) samples by the PcAb- and combination-based Ag-ELISAs respectively, of which 48 (63%) and 34 (69%) were also positive by the DIA.     

Helminths of sheep and goats in desert areas of south-west Mauritania (Trarza)

Faecal samples were obtained from sheep and goats before, during and after the rainy season at three locations in south-west Mauritania. Several animals were also necropsied at the same time.Haemonchus contortus was the most prevalent worm. Infection by digestive-tract strongyles andStrongyloides papillosus was always very light (prevalence less than 20%). Sheep were more heavily infected than goats but animals under 1 year of age were not infected by digestive-tract strongyles. It is likely that young small ruminants became infected during the rainy season and that the parasites so acquired are inhibited in their development and/or survive nearly one year as adults.     

Application of the California mastitis test in intramammary Streptococcus agalactiae and Staphylococcus aureus infections of camels (Camelus dromedarius) in Kenya

A study was conducted on 207 lactating camels in six herds in Kenya to evaluate the California mastitis test (CMT) for the detection of intramammary infections (IMIs) caused by Streptococcus agalactiae and Staphylococcus aureus and to investigate the prevalence of both the pathogens in the camel udder. IMI with S. agalactiae was found in 12% of all camels sampled. IMI with S. aureus was present in 11% of all camels sampled. The herd-level prevalence of IMI varied between 0 and 50% for S. agalactiae and between 0 and 13% for S. aureus. Longitudinal observations over 10–12 months confirmed persistent infections for both pathogens. Observations in one herd suggested that camel pox was a contributing factor in spreading and exacerbating S. agalactiae udder infections.The CMT had quarter-level sensitivities of 77 and 68% for S. agalactiae and S. aureus in camels, respectively. The CMT specificities were 91% for both the pathogens.     

Suspected natural lysosomal storage disease from ingestion of pink morning glory (Ipomoea carnea) in goats in northern Argentina

This study describes an occurrence of pink morning glory (Ipomoea carnea) intoxication in goats in northern Argentina. The clinical signs displayed by the affected animals were ataxia, lethargy, emaciation, hypertonia of the neck muscles, spastic paresis in the hind legs, abnormal postural reactions and death. The clinico-pathologic examination revealed that the affected animals were anemic and their serum level of aspartate aminotransferase was significantly increased. Cytoplasmic vacuolation in the Purkinje cells and pancreatic acinar cells was observed by histological examination. The neuronal lectin binding pattern showed a strong positive reaction to WGA (Triticum vulgaris), sWGA (succinylated T. vulgaris) and LCA (Lens culinaris). Although I. carnea is common in tropical regions, this is the first report of spontaneous poisoning in goats in Argentina.     

The relationship between serum level of thyroid hormones,trace elements and antioxidant enzymes in dromedary camel (<Emphasis Type="Italic">Camelus dromedarius</Emphasis>)

Thyroid hormones might be able to regulate the activities of superoxide dismutase (SOD), catalase and glutathione peroxidase (GPX). The role of thyroid hormones in metabolic pathways and antioxidant enzyme activities are well known in many species. Nevertheless, there is no report describing probable relationship between thyroid hormones status, erythrocyte antioxidant enzymes and serum profiles of trace elements. This study was undertaken to investigate the relationship between these parameters in Iranian dromedary camels. Blood samples were taken from the jugular vein of 30 clinically healthy Iranian dromedary camels under aseptic conditions during 6 consecutive days of summer. The serum was analyzed for serum profile of thyroid hormones, trace elements, SOD and GPX activity. There were no significant differences in serum thyroid hormones, serum level of zinc (Zn), copper (Cu), manganese (Mn), iron (Fe), selenium and antioxidant enzymes in different days (P > 0.05). There was a significant negative correlation between SOD and Fe (P < 0.01, r = -493). There was no significant correlation between other parameters. In case of copper deficiency likewise the present study, the copper was used to produce more SOD, so there was a decrease in Fe transportation, and it might be a cause of decrease in Fe amount. On the other hand, a relatively small quantity of Fe is present in tissue myoglobin, catalase, peroxidases, and cytochromes. So it might be another cause of decrease in Fe amount. The explanation for these finding is not possible at this moment and further investigations are needed to interpret these changes.     

Salmonella Prevalence and Distribution of Serotypes in Apparently Healthy Slaughtered Camels (Camelus dromedarius) in Eastern Ethiopia

The present study was undertaken to determine the prevalence and distribution of Salmonella from apparently healthy slaughtered camels in Eastern Ethiopia. A total of 714 samples (faeces, mesenteric, lymph nodes, spleen, liver, abdominal and diaphragmatic muscles) from 119 slaughtered camels were analysed. Salmonellae were detected from 116 (16.2%) of the 714 samples examined. Eighteen (15.1%) faeces, 19 (15.9%) mesenteric lymph nodes, 14 (11.8%) livers and 17 (14.3%) spleen samples (n = 119 for each) were positive for Salmonella. Salmonellae were found in 20.1% of the abdominal and diaphragmatic muscles. A total of sixteen different serotypes were identified of which Salmonella saintpaul (38.8%) and S. braenderup (22.4%) were the most prevalent followed by S. muenchen (8.6%), S. kottbus (6.0%) and S. havana (5.2%). Other serotypes, including S. typhimurium, S. heidelberg and S. enteritidis were also detected from Ethiopian camels.     

The detection of subclinical mastitis in the bactrian camel (Camelus bactrianus) by somatic cell count and California mastitis test

Milk samples (n=160) from 7 clinically healthy bactrian camels were cultured to detect subclinical udder infection. The samples were assessed by the Californian mastitis test (CMT) and somatic cell count (SCC). Bacteria were recovered from 36 (22.5%) of the milk samples. Staphylococcus aureus and coagulase-negative staphylococci (CNS) were the main organisms found.Infected quarters had significantly higher mean values for the SCC (p<0.01) and CMT (p<0.001) than non-infected quarters. All 7 camels were infected with CNS but only 4 with S. aureus. CMT values for S. aureus-infected camels were significantly higher than for those only infected with CNS. The values for SCC and CMT were significantly influenced by the stage of lactation (p<0.05). No significant difference was found from the effect of the quarters. Both SCC and CMT were of value in predicting the infection status of the udder.Abbreviations CMT California mastitis test - SCC somatic cell count - CNS coagulase-negative staphylococci     

The effect of long-term feeding of fresh and ensiled cassava (Manihot esculenta) foliage on gastrointestinal nematode infections in goats

The benefit of long-term feeding of fresh or ensiled cassava foliage on gastrointestinal parasite in goats was evaluated. Eighteen male goats (15.15 ± 2.83kg and between 4–6months) were randomly allocated into three treatments supplemented with 200g of wheat bran head⁻¹ day⁻¹. All groups were fed ad-libitum on either grass (CO), fresh cassava (CaF) or ensiled cassava foliage (CaS). At the beginning of the trial, each goat was inoculated with 3000 L3 containing ≈50% Haemonchus contortus. Individual LWt, FEC and PCV were measured at weekly intervals for 10weeks. At the termination of the experiment all goats were slaughtered for worm recovery and enumeration. The goats in CaF and CaS had similar weight gains while those in CO lost weight (p < 0.05) through the trial. FEC in CaF and CaS were lower (p < 0.05) than CO during the patency of parasite infections, but there was no difference between CaF and CaS goats. PCV of all groups decreased from above 30% to around 25% at the end of the trial. The compositions of established worm burdens were mainly H. contortus (19–40%) and Trichostrongylus colubriformis (55–76%). TWB did not differ among the groups, however, CaS significantly reduced H. contortus burdens, as compared to CaF and CO (p ≤ 0.005). Thus, ensiled cassava foliage reduced the H. contortus population while the fresh foliage only reduced worm fecundity.     

Serological response of guinea pigs to oily and aqueous inactivated vaccines containing a Brazilian isolate of the Bovine Viral Diarrhea Virus (BVDV)

Bovine Viral Diarrhea Virus (BVDV) is widespread in cattle in Brazil and research shows its large antigenic variability. Available vaccines are produced with virus strains isolated in other countries and may not be effective. In this study, inactivated vaccines containing the Brazilian BVDV-Ib IBSP11 isolate were developed and tested on 6 groups of 10 guinea pigs (Cavia porcellus). Animals in groups A and C received an aqueous vaccine (aluminum hydroxide); B and D groups received an oily vaccine (Montanide ISA50); Group E positive-control animals were given an imported commercial vaccine with BVDV-Ia Singer; Group F animals were sham vaccinated (negative control). Groups A, B and E received two doses, and Groups C and D, three, every 21 days. Twelve blood samples were taken, at 21-day intervals over 231 days, and evaluated for antibody titer through virus-neutralization (VN), using a homologous strain (IBSP11), and a heterologous strain (BVDV-Ia NADL). Most animals, 42 days following the first dose, seroconverted to both strains and, after the second dose, there was a significant increase of titers in all groups. The oily formulation induced greater response after the third administration. This increase was not observed with the aqueous vaccines, regardless of the virus used in the VN. Antibody decline was more rapid in animals that received aqueous vaccines. The results showed the importance of studying the influence of endemic strains of commercial vaccines, to improve the efficacy of BVD vaccination. Use of the endemic strain in vaccine formulation presented promising results, as well as the use of guinea pigs as a laboratory model.     

Molecular characterization of Mycobacterium tuberculosis complex (MTBC) isolated from cattle in northeast and northwest China

We studied throat swabs and corresponding serum samples collected from 1067 protein purified derivative (PPD)-tuberculin skin test (TST) positive cattle from different regions of China. The 1067 throat swabs were inoculated onto modified Löwenstein–Jensen medium for the isolation and culture of Mycobacteria. Acid-fast bacilli were identified using traditional biochemical methods, polymerase chain reaction (PCR) amplification and multiplex PCR. They were distinguished as Mycobacterium tuberculosis complex (MTBC) and non-tuberculous mycobacteria (NTM) strains. An indirect Enzyme-Linked Immunosorbent Assay (ELISA) was applied to detect specific antibodies against bovine TB (bTB). Correlations among the ELISA, bacteriology and TST were analyzed and compared. Spoligotyping and variable number tandem repeats–mycobacterial interspersed repetitive unit (VNTR–MIRU) analysis were used to genotype the MTBC. In total, 111 strains of Mycobacteria were cultured from the 1067 throat swab samples, including 43 stains of MTBC (14 strains of Mycobacterium bovis and 29 of Mycobacterium tuberculosis) and 68 strains of NTM. Thirty-eight MTBC strains and four NTM strains were isolated from 72 throat swab samples that the ELISA determined were antibody positive; five MTBC strains and 64 NTM strains were isolated from 995 throat swab samples that were antibody negative on the ELISA. The positive isolation rates of MTBC and NTM were 38.7% (43/111) and 61.3% (68/111), respectively. The concordance rate of cultured MTBC with a positive result on the indirect ELISA for antibody was 52.8% (38/72), which was much higher than the positive rate for TST (4.0%; 43/1067). Genotyping of the 43 strains of MTBC isolated, using spoligotyping and VNTR–MIRU, showed that the 43 isolates had 26 genotypes; 16 strains had a unique genotype. Two groups of six strains and two strains, respectively, showed the same spoligotyping pattern, and belonged to the Beijing family and Beijing-like family, respectively. Combined application of spoligotyping and VNTR–MIRU typing would improve the molecular epidemiological investigation and monitoring of the etiology of bTB in China.     

The in vitro effect of six antimicrobials against Mycoplasma putrefaciens, Mycoplasma mycoides subsp. mycoides LC and Mycoplasma capricolum subsp. capricolum isolated from sheep and goats in jordan

Respiratory disease in sheep and goats is a major problem in Jordan and is often associated with Mycoplasma species. Without effective vaccines, control is mainly by chemotherapy, but the uncontrolled use of antimicrobials has led to concerns about the potential development of antimicrobial resistance. The in vitro effect of chloramphenicol, florfenicol, enrofloxacin, tylosin, erythromycin and oxytetracycline was determined against 32 isolates of Mycoplasma species-M. mycoides subsp. mycoides LC (6), M. capricolum subsp. capricolum (8) and M. putrefaciens (18), all isolated from either nasal swabs or milk, from sheep and goats in different regions of Jordan. The antimicrobial susceptibility showed some Mycoplasma species-specific differences, with M. capricolum subsp. capricolum being more susceptible to tylosin and erythromycin. Chloramphenicol and florfenicol were the least effective for all three Mycoplasma species. No trends or significant differences in antimicrobial susceptibilities were observed between sheep and goat isolates, between milk or nasal swab isolates, or between isolates from different regions of Jordan. Some isolates of M. capricolum subsp. capricolum and M. putrefaciens showed higher MIC levels with oxytetracycline, as did two isolates of M. mycoides subsp. mycoides LC with tylosin, possibly indicating signs of development of antimicrobial resistance.     

Detection of a novel hemoplasma based on 16S rRNA gene DNA in captive and free-ranging capybaras (Hydrochaeris hydrochaeris)

Two different species of hemoplasmas, Mycoplasma coccoides and M. haemomuris, are known to infect small rodents such as mice and rats. However, there are no previous reports of hemoplasma infection in capybara (Hydrochaeris hydrochaeris). The aim of our study was to determine whether these hemoplasmas might infect capybaras from Southern Brazil. Blood samples from 31 animals: 10 captive and 21 free-ranging capybaras were collected and packed cell volume and total plasma protein were measured. DNA was extracted and PCR assays for M. coccoides and M. haemomuris were performed. Using the M. coccoides-PCR assay 64% of the capybaras were positive, 80% free-ranging and 30% from captive animals. The prevalence of infection between the groups was significantly different (p = 0.001). Sequencing of the nearly entire 16S rRNA gene from the positive samples suggested a novel hemoplasma isolate with identity of 92% with M. coccoides and 86% with M. haemomuris. All capybara samples were negative for M. haemomuris infection. DNA of a housekeeping gene was successfully amplified from all samples. This is the first evidence of a hemoplasma infection in capybaras.     

Molecular identification and characterization of Mycobacterium avium subspecies paratuberculosis in free living non-human primate (Rhesus macaques) from North India

In recent years, Mycobacterium avium subspecies paratuberculosis (MAP) has emerged as major animal pathogen with significant zoonotic concerns, worldwide. MAP infection is endemic in domestic and wild ruminant population in India. However, information on MAP infection in free ranging animal species and non human primates is limited. Present study aimed to estimate the status of MAP infection in free living Rhesus macaques suffering with multiple clinical conditions (coughing and loose stool). A total of 25 stool samples were collected from six colonies of Rhesus macaques from Mathura region (North India) and screened for the presence of MAP, using microscopic examination and IS900 PCR, directly from stool samples. PCR positive DNA samples were further genotyped using IS1311 PCR-restriction enzyme analysis. Of the 25 stool samples, 10 (40.0%) and 2 (8.0%) were positive for MAP using microscopic examination and direct IS900 PCR, respectively. IS900 PCR positive DNA samples were genotyped as ‘Indian Bison type’, which is a major MAP genotype infecting domestic and wild ruminant species and human beings in India. Prevalence of MAP in Rhesus macaques (Indian monkeys) was moderately high and confirmed interspecies sharing of MAP between domestic livestock and non-human primates. Presence of MAP in non-human primates, support the etiological role of MAP in inflammatory bowel disease patients. Indian monkeys may serve as model for understanding the role of non-human primates in sustenance, transmission and pathogenesis of MAP infection.     

Bovine Herpesvirus 5 (BoHV-5) in Bull Semen: Amplification and Sequence Analysis of the US4 Gene

Bovine herpesvirus type 5 (BoHV-5), which is potentially neuropathogenic, was detected in clinical samples of bovine semen, both directly and after isolation in cell culture, using a nested PCR system for amplifying the US4 gene. Nucleotide sequences generated from the amplicons were analysed and deposited at GenBank (NCBI, Bethesda, MD, USA) under the accession numbers AF298174 and AF330157. Alignment of these sequences and previously deposited sequences of BoHV-1 and BoHV-5 showed 82% and 98% similarity, respectively. The bulls, which were maintained at an artificial insemination centre, had presented no clinical signs, indicating that bovine semen should be screened for BoHV-5 to prevent transmission of the virus.     

Resistance patterns and detection of aac(3)-IV gene in apramycin-resistant Escherichia coli isolated from farm animals and farm workers in northeastern of China

The aminoglycoside apramycin has been used widely in animal production in China since 1999. This study was aimed to investigate the resistance pattern of apramycin-resistant Escherichia coli isolated from farm animals and farm workers in northeastern of China during 2004–2007 and to determine whether resistance to apramycin was mediated by plasmid containing the aac(3)-IV gene and the mode for the transfer of genetic information between bacteria of farm animals and farm workers. Thirty six E. coli isolates of swine, chicken, and human origins, chosen randomly from 318 apramycin-resistant E. coli isolates of six farms in northeastern of China during 2004–2007, were multi-resistant and carried the aac(3)-IV gene encoding resistance to apramycin. Conjugation experiments demonstrated that in all 36 cases, the gene encoding resistance to apramycin was borne on a mobilisable plasmid. Homology analysis of the cloned aac(3)-IV gene with the sequence (accession no. X01385) in GenBank showed 99.3% identity at a nucleotide level, but only with a deletion of guanosine in position 813 of the gene in all 36 cases. The results indicted that resistance to apramycin in these isolates was closely related to aac(3)-IV gene. Therefore, the multi-resistance of E. coli could complicate therapeutic practices for enteric infections in both farm animals and human.     

The ability to enter into an avirulent viable but non-culturable (VBNC) form is widespread among Listeria monocytogenes isolates from salmon, patients and environment

Media-based bacteriological testing will fail to detect non-culturable organisms and the risk of consuming viable but non-culturable (VBNC) Listeria monocytogenes is unknown. We have here studied whether L. monocytogenes obtained from seafoods, processing environment and clinical cases enter the VBNC state and assessed the virulence of the non-culturable forms of the bacteria. A number of 16 L. monocytogenes strains were starved in microcosm water at 4 °C until loss of culturability. Metabolic activity in the VBNC form was measured as ATP generation using a luciferase assay and membrane integrity was examined using the LIVE/DEAD BacLight assay. All tested L. monocytogenes strains entered the VBNC state after starvation in microcosm water. Ongoing mRNA synthesis of hly in VBNC L. monocytogenes cells re-incubated in culture medium indicated a potential virulence of these forms. Sodium pyruvate and replenishment of nutrient were used in attempts to resuscitate VBNC cells. However, VBNC L. monocytogenes were not resuscitated under these conditions. VBNC L. monocytogenes were tested for virulence in a cell plaque assay and by intraperitoneally inoculation in immunodeficient RAG1^−/− mice. Inoculation of VBNC L. monocytogenes in immunodeficient mice did not cause morbidity, and plaque assay on HT-29 cells in culture indicated that the VBNC cells were avirulent. The results indicate that the risk of non-culturable L. monocytogenes in foods, when the VBNC state is induced by starvation, is negligible.