A case of "misplaced" Tritrichomonas foetus infection in a dog in Northern Italy.

An 8-year-old, spayed female Rottweiler dog, under immunosuppressant treatment for protein-losing enteropathy (PLE) and intestinal lymphangiectasia, was presented for anorexia, poor general conditions and episodes of diarrhea. A subcutaneous mass between the caudal abdominal mammary glands was found. A fine-needle aspiration cytology was performed and revealed the presence of inflammatory cells mixed with pear- or round-shaped microorganisms with cytomorphological features of flagellated protozoan trophozoites, belonging to Trichomonadida order. The final diagnosis of Tritrichomonas foetus infection was achieved with molecular analysis (Real-Time PCR) and sequencing. T. foetus has often been reported as a pathogenic agent in cattle and cats, and rarely reported in dogs, where its pathogenetic role is poorly understood. To the author's knowledge, this is the first case of T. foetus infection described in a location different from the gastrointestinal tract in a dog.

An Unusual Case of Feline Leishmaniosis With Involvement of the Mammary Glands.

We report an unusual case of leishmaniosis with the involvement of mammary glands in an old cat with what seems to be a concurrent regressive feline leukemia virus infection. Leishmania donovani complex parasites were identified for the first time in inflammatory breast fluid during a clinical recurrence manifested about 4 years after the first diagnosis of feline leishmaniosis. Combined treatment with allopurinol and meglumine antimoniate resulted in clinical cure of mammary lesion and a concurrent uveitis.

Divergent selection on milk somatic cell count in goats improves udder health and milk quality with no effect on nematode resistance.

Milk somatic cell count (SCC) is commonly higher in goats than in cattle and sheep. Furthermore, the ability of milk SCC to predict mastitis is considered lower in goats than in cattle and sheep, and the relevance of somatic cell score (SCS)-based selection in this species has been questioned. To address this issue, we created 2 divergent lines of Alpine goats using artificially inseminated bucks with extreme estimated breeding values for SCS. A total of 287 goats, 158 in high- and 129 in low-SCS lines, were scrutinized for mastitis infections. We subjected 2,688 milk samples to conventional bacteriological analyses on agarose and bacterial counts were estimated for positive samples. The SCS, milk yield, fat content, and protein content were recorded every 3 wk. Clinical mastitis was systematically noted. A subset of 40 goats (20 from each line) was subsequently challenged with Haemonchus contortus and monitored for anemia (blood packed cell volume) and fecal egg counts to see if SCS-based selection had an indirect effect on resistance to gastrointestinal nematodes. Milk production traits, including milk quantity, fat content, and protein content, were similar in both goat lines. In contrast, the raw milk SCC almost doubled between the lines, with 1,542,000 versus 855,000 cells/mL in the high- and low-SCS lines, respectively. The difference in breeding value for SCS between lines was 1.65 genetic standard deviation equivalents. The Staphylococcus spp. most frequently isolated from milk were S. xylosus, S. caprae, S. epidermidis, and S. aureus. The frequency of positive bacteriology samples was significantly higher in the high-SCS line (49%) than in the low-SCS line (33%). The highest odds ratio was 3.49 (95% confidence interval: 11.95-6.25) for S. aureus. The distribution of bacterial species in positive samples between lines was comparable. The average quantity of bacteria in positive samples was also significantly higher in high-SCS goats (69 ± 80 growing colonies) than in low-SCS goats (38 ± 62 growing colonies). Clinical cases were rare and equally distributed between high- (n = 4; 2.5%) and low-SCS (n = 3; 2.3%) lines. Furthermore, the larger the amounts of bacteria in milk the higher the SCS level. Conversely, goats with repeatedly culture-negative udders exhibited the lowest SCC levels, with an average of below 300,000 cells/mL. We therefore confirmed that SCS is a relevant predictor of intramammary infection and hygienic quality of milk in goats and can be used for prophylactic purposes. After challenge with H. contortus, goats were anemic with high fecal egg counts but we found no difference between the genetic lines. This result provides initial evidence that resistance to mastitis or to gastrointestinal nematodes infections is under independent genetic regulation. Altogether, this monitoring of the goat lines indicated that SCS-based selection helps to improve udder health by decreasing milk cell counts and reducing the incidence of infection and related bacterial shedding in milk. Selection for low SCC should not affect a goat's ability to cope with gastrointestinal nematodes.

Short communication: Occurrence and persistence of Prototheca zopfii in dairy herds of Korea.

Bovine mastitis caused by Prototheca has been reported globally, and its incidence is increasing in dairy herds. The present study aimed to investigate the occurrence of Prototheca and persistence of Prototheca zopfii strains in Korean dairy herds. A total of 187 (7.5%) P. zopfii strains were isolated from 2,508 quarter milk samples collected from 50 dairy farms throughout Korea from 2015 to 2017. Prototheca zopfii was isolated from one farm among the 50 farms over the 3-yr period. The P. zopfii isolates belonged to genotype 2. Overall, Prototheca-positive quarter milk samples showed high somatic cell counts with an average value of log 6.48 ± 6.54 cells/mL. Prototheca zopfii was found to be persistent in an infected farm over a 2-yr period. To the best of our knowledge, this is the first report on the presence and persistence of protothecal mastitis caused by P. zopfii genotype 2 in a Korean dairy herd. This disease leads to a significant increase in somatic cell counts in milk, which persists for more than 1 yr in the affected cow udder. These results suggest that P. zopfii could pose a serious risk to dairy herds. Thus, strict surveillance for protothecal mastitis is urgently needed and sanitary conditions regarding the environment and milk collection are essential because of the lack of effective treatment options.

Important knowledge gaps among pastoralists on causes and treatment of udder health problems in livestock in southern Ethiopia: results of qualitative investigation.

BACKGROUND: Ethiopia has high prevalences of udder health problems including clinical and subclinical mastitis across production systems in different livestock species. Previous studies on udder health problems have largely focused on identification of mastitis causing microbial pathogens and associated risk factors. However, relatively little is known about the knowledge and beliefs of livestock keepers regarding udder health problems. An understanding of the beliefs on the other hand would facilitate effective communication between livestock keepers and animal health professionals. Therefore, this study aimed at exploring the knowledge and belief surrounding the causes, clinical signs and treatments for udder health problems in (agro-) pastoral communities in southern Ethiopia using qualitative investigation. RESULTS: The result showed that udder health problem, locally known as 'dhukkuba muchaa', which translates to 'disease of teats', was classified into three main types: (1) tick infestation (dirandisa), (2) swelling of udder often with pus discharge (nyaqarsa) and (3) acute mastitis caused by evil eye (buda) with 'bloody milk'. Tick infestation was perceived to directly cause mechanical damage to udder tissue or to resulting in swelling leading to nyaqarsa. Our analysis also revealed the strong misperception that acute and severe swelling of udder was caused by evil eye. According to the pastoralists, cows with large udders in the late pregnancy are prone to evil eye infliction upon giving birth. The pastoralists often treat udder health problems by combining both modern and traditional methods. Removal of ticks by hand and acarcide application were the preferred methods for limiting tick infestation while swelling and evil eye cases were treated with antibiotics (e.g. oxytetracycline). The study also revealed that specific herbs, only known by the herbalists, were used for traditional treatment of udder health. Although this information could not be divulged at the time, it should form the subject of further investigation. Traditional treatment for evil eye was often administered through nostrils, raising questions about its effectiveness. CONCLUSION: The narration given by the pastoralists in associating tick infestation with udder health problems was compatible with existing scientific evidences. In this respect, such local knowledge can be better utilized for the educational messages targeting control and management of tick infestation in livestock. However, the misperception of causes for acute udder swelling as evil eye can be problematic as far as the application of appropriate treatment and management of the problem is concerned. The misperception can significantly impact the welfare of animals and highlights the need for capacity building of the pastoralists on the causes and treatment of udder health problems.

Identification of microfilaria in a mammary mass aspirate from a female dog.

A filarial nematode larva (microfilaria) was found in an aspirate of a mammary mass from a dog imported to Saskatchewan from Myanmar. This was an unusual location for a microfilaria and numerous filarial nematodes infecting dogs in Asia had to be considered. This report describes the laboratory diagnosis of canine heartworm disease in this dog.

Identification de la microfilaire dans le prélèvement par aspiration d'une masse mammaire chez une chienne. Une larve de nématode filaire (microfilaire) a été trouvée dans un prélèvement par aspiration d'une masse mammaire chez un chien importé en Saskatchewan en provenance du Myanmar. Il s'agissait d'un emplacement inhabituel pour une microfilaire et plusieurs nématodes filaires infectant les chiens en Asie ont dû être considérés. Ce rapport décrit le diagnostic de laboratoire de la maladie du ver du coeur canin chez ce chien.(Traduit par Isabelle Vallières).

[Assessment of transmammary transmission of Trichinella patagoniensis in BALB/c mice]. / Evaluación de la transmisión galactógena de Trichinella patagoniensis en ratones BALB/c.

Since 1916 to date, it has been suspected that vertical transmission of parasites from the genus Trichinella could occur in pregnant or lactating women during the parenteral phase of infection. The aim of the present study was to evaluate the transmammary transmission of T. patagoniensis in BALB/c mice. Twenty 7-week-old BALB/c mice were distributed into two groups of 10 individuals each, depending on the time of gestation when they were infected, 15 or 18 days after detection of the vaginal plug. Each group was subdivided into two subgroups of 5 mice each, which were given an oral dose of 100 or 500 infective larvae respectively. Euthanasia and subsequent artificial digestion was performed in the pups and the dams. No T. patagoniensis L1 larvae were found in any of the offsprings analyzed. The observed results suggest that vertical transmission of T. patagoniensis would not be possible in BALB/c mice.

Occurrence of Leishmania infantum and associated histological alterations in the genital tract and mammary glands of naturally infected dogs.

The objectives of this study were to evaluate the occurrence of Leishmania infantum in the male and female genital tract and female mammary glands of dogs and the parasite burden and to identify histological alterations associated with this protozoan. Twenty male and 20 female Leishmania-seropositive dogs with isolation of L. infantum were examined. Tissue samples of the prepuce, glans, epididymis, testes, prostate, vulva, vagina, uterus, uterine tubes, and mammary glands were analyzed by immunohistochemistry and histopathology. For parasitological culture and in situ hybridization, samples were collected from the testis, epididymis, and uterus. Additionally, seminal fluid was aspirated from the epididymis for parasitological culture. In the genital tract, 34 (85 %) dogs, including 18 males and 16 females, were positive for Leishmania. Of these, 27 (79 %) animals were symptomatic. Leishmania was detected in the mammary glands of 13 (65 %) females. L. infantum was isolated for the first time from the seminal fluid and uterus of naturally infected dogs. The parasite burden and intensity of the inflammatory reaction were greater in the prepuce and glans of males and in the vulva and mammary glands of females. In addition to inflammation, testicular degeneration, atrophy, absence of spermatogenesis, and necrosis were observed. Detection of amastigote forms in the mammary gland lumen indicates possible elimination of this parasite in milk. The frequent parasitism observed in the genital tract of infected males and females and the viability of L. infantum in seminal fluid and uterus suggest the possibility of bidirectional venereal and vertical transmission.

Transmammary infection in BALB/c mice with chronic toxocariasis.

Human toxocariasis is a neglected public health problem. Infection of humans generally results from the accidental ingestion of embryonated Toxocara canis eggs, but it is important to broaden knowledge about other forms of transmission. This study aimed to demonstrate the prevalence of transmammary transmission in mice with chronic toxocariasis. BALB/c mice in groups 1 (G1) and 3 (G3) were inoculated with 1200 T. canis eggs 60days before mating, whereas those of group 2 (G2) were not infected. After delivery, the G1 neonates were transferred to G2 females to be nursed, and vice versa. Thus, the mice generated by G2 females and breastfed by G1 females could be infected only during lactation. In the G3 group, offspring were not exchanged. The search for T. canis larvae in the bodies of the lactating females and their offspring was performed after weaning and at 60days old, respectively. The frequency of transmammary infection in the mice generated by G2 uninfected females and breastfed by G1 infected females was 19.8%, which was similar to that observed (19.6%) in the mice bred and fed by G3 females. The frequency of infection in the mice generated by G1 females and breastfed by G2 females was only 4.2%, which was lower than that of G1 (p=0.0064) and G3 (p=0.0062) groups. Transmammary infection by mice with chronic toxocariasis was found to be more prevalent than congenital infection.

Bacterias patógenas potenciales al inicio del período seco de vacas doble propósito con mastitis subclínicas / Potential pathogen bacteria during the dry period in dual purpose cows with subclinical mastitis

Los aportes científicos en el campo de la producción láctea alcanzan más de 100 años de arduo estudio, con el fin de producir la mayor cantidad de leche por vaca/año acompañado de una excelente salubridad de la glándula mamaria. Esta salud de la ubre se ha visto afectada por la inflamación del parénquima denominada mastitis causada generalmente por bacterias como los Staphylococcus spp., Streptococcus spp., Corynebacterium spp., enterobacterias, entre otras. El objetivo de este trabajo fue determinar las bacterias existentes en glándulas mamarias con mastitis subclínica al inicio del período seco. Para ello se seleccionaron al azar 39 vacas mestizas doble propósito multíparas al final de la lactancia procedentes de un mismo sistema de producción, con siete meses de gestación, negativas en la prueba de fondo negro y con resultados de CMT ³ +2. Se tomaron muestras de leche para estudio bacteriológico. Se observó crecimiento bacteriano a partir de la leche de 96 cuartos mamarios (61,53%) y en la leche de 49 cuartos no hubo crecimiento (31,41%). Las bacterias más aisladas fueron el Corynebacterium bovis (46,73%), Staphylococcus epidermidis (20,56%), Staphylococcus aureus (12,15%) y Arcanobacterium pyogenes (7,48%). De acuerdo al tipo de crecimiento, se obtuvo un 88,54% de crecimiento puro y un 11,46% de crecimiento mixto y de acuerdo al potencial de patogenicidad se obtuvo un 73,82% de patógenos menores y un 18,69% de patógenos mayores. En conclusión, se identificaron las bacterias presentes en la glándula mamaria con mastitis subclínica al inicio del período seco, su distribución en cuanto a género, especie, tipo de crecimiento y potencial de patogenicidad. Asimismo, estas bacterias pueden generar mastitis clínica en el período productivo con la consecuente baja en la calidad y cantidad de leche producida.

Scientific research in milk production has been evolving over more than 100 years to attain the highest amount of milk/ cow/year along with an excellent health status of the mammary gland. This health status of the mammary gland is affected by parenchymal inflammation, i.e. mastitis, caused in general by bacteria, such as Staphylococcus spp., Streptococcus spp., Corynebacterium spp. and enterobacteria. The objective of this trial was to determine the bacterias present in mammary glands with subclinical mastitis at the beginning of the dry period. Thirty nine (39) multiparous crossbred dual purpose cows at the end of the lactating period were randomly selected; they had a seven-month gestation, and they were negative at the black bottom cup test; they have a ³ +2 score at the CMT as well. Milk samples were taken for bacteriological study. Bacterial growth was observed in milk sample from 96 udder quarters (61.53%) and in milk sample from 49 quarters there was no growth (31.41%). The most frequently isolated bacteria were Corynebacterium bovis (46.73%), Staphylococcus epidermidis (20.56%), Staphylococcus aureus (12.15%) and Arcanobacterium pyogenes (7.48%). As for growth type, 88.54% of cultures were pure cultures and 11.46% were mixed cultures. As for pathogenicity potential, 73.82% of the isolates were minor pathogens and 18.69% were major pathogens. In conclusion, bacteria in mammary glands with subclinical mastitis at the dry period, their distribution as for genus and species, growth type and pathogenicity potential were identified. On other hand, these bacteria can generate clinical mastitis in the lactating period with the resulting decrease in the quality and quantity of yielded milk.

Prolactin evokes lactational transmission of larvae in mice infected with Toxocara canis.

We investigated the trans-lactational maternal-neonatal transmission of Toxocara canis larvae in mice, with particular interest in the role of prolactin in their migration to the mammary gland. Two female mice were infected with 300 T. canis eggs soon after delivery of 27 offspring. After 1 week of breast-feeding, seven larvae were recovered from 4 of 13 offspring. After 2 weeks of lactation, 101 larvae were recovered from all the remaining offspring. Daily prolactin administration (5 microg) was performed 2 weeks before T. canis infection and continued until 2 weeks after infection in six non-pregnant female mice, which resulted in larval accumulation in the mammary gland. Furthermore, prolactin administration in female mice that had been infected with T. canis 4 weeks prior to prolactin treatment induced migration of larvae into the mammary gland. These findings suggest that prolactin is a promoting factor contributing to lactational transmission of T. canis larvae in mice.

Cutaneous toxoplasmosis in a female Japanese cat.

A 16-year-old female Japanese cat was presented with a single mammary-gland nodule approximately 3 cm in diameter. Histologically, the nodule consisted of necrotizing granulomatous panniculitis, vasculitis, and mastitis, and contained free and clustered protozoal organisms. The organism was present in the cytoplasm of macrophages, fibroblasts, endothelial cells, and mammary-gland epithelia. The organism was positive for anti- Toxoplasma gondii and anti- Neospora caninum antibodies. Electron microscopy showed single and grouped tachyzoites, with morphologic features similar to those of T. gondii. Polymerase chain reaction and deoxyribonucleic acid sequence analysis was consistent with T. gondii infection. This is the first report of cutaneous toxoplasmosis in a Japanese cat.

Fluorescent in situ hybridization as a tool to retrospectively identify Cryptosporidium parvum and Giardia lamblia in samples from terrestrial mammalian wildlife.

Fecal samples of five terrestrial mammalian wildlife species stored at 4 degrees C or at -20 degrees C for up to 36 months have been tested for human zoonotic enteric parasites (i.e., Cryptosporidium parvum and Giardia lamblia) using combined fluorescent in situ hybridization (FISH) and direct fluorescent antibody techniques. The prevalence of C. parvum and G. lamblia varied from 20 to 63% (mean, 45.8%) and from 13 to 100% (mean, 53.2%), respectively. The prevalence of C. parvum and G. lamblia infections was higher in small rodents (mean, 68.5%) than in other wildlife (mean, 21%). Overall, 31.1% of animals were coinfected, and coinfections were more prevalent in small rodents (mean, 52%) than in other wildlife species (mean, 13.2%). The present study has shown that the FISH assay can be retrospectively applied to fecal samples for the identification of C. parvum oocysts, but is less suitable for the identification of G. lamblia cysts in such samples. Terrestrial mammalian wildlife, particularly small rodents, can contribute to watershed contamination with C. parvum oocysts and G. lamblia cysts. To control contamination, the management of pristine watersheds used for drinking water purposes should incorporate control measures for terrestrial wildlife, especially field rodents residing within such watersheds.

Comparative effect of Neospora caninum infection in BALB/c mice at three different gestation periods.

Neospora caninum has been recognized as a major cause of infectious bovine abortion worldwide. In the present study, the effect of N. caninum infection in mice at the 3 gestation periods (first, second, and third period) was investigated. In dams, tissue distribution of N. caninum was evaluated by nested polymerase chain reaction. In the progeny, fetal mortality, stillbirth, litter size, neonatal mortality/morbidity, vertical transmission, and parasite burden in neonatal tissues were evaluated. Pregnant BALB/c mice were infected subcutaneously with 2 x 10(6) NC-1 tachyzoites on days 0, 7, or 14 of gestation. Dams from each group were sequentially killed during gestation and postpartum (PP). Pups were killed on days 1 and 7 PP. Infection on day 0 of gestation produced a high vertical transmission rate, although no changes in fetal mortality, stillbirth, and littermate size were observed. The highest level of vertical transmission, together with an increase in fetal mortality and stillbirth and a decrease in litter size, were observed when infection was done on day 7 of gestation. Finally, infection on day 14 of gestation produced the lowest vertical transmission. Furthermore, infection at any time during gestation compromised the postnatal development of pups, because neonates from infected dams showed less body weight and a delay in the hair development.

Unusual finding in a nipple discharge of a female dog: dirofilariasis of the breast.

We report a case of dirofilariasis of the breast occurring in a 6-yr-old Bernese female dog living in central Italy presenting with a breast lump, diagnosed on cytological examination of nipple secretion fluid smears. The direct smears of nipple discharge revealed clusters of glandular cells characterized by mild pleomorphic appearance and the presence of some nematodes of about 350 microm in length in the background. The smears also contained several inflammatory cells, including eosinophils. Both the Knott and the antigen tests were negative for Dirofilaria immitis. The morphological features of this round worm is compatible with that of Dirofilaria repens. The case describes an unusual finding of dirofilariasis presenting as a breast lump, simulating an inflammatory breast carcinoma.

Teat onchocercosis in cows with reference to prevalence, species involved and pathology.

The present study reports teat onchocercosis in cows in the province of Kars in north eastern Turkey with reference to the prevalence, species involved and pathological findings. In the study, 600 cows of various breeds and ages slaughtered in the local abattoir were examined and 145 (24%) were found to have various lesions on their teats, of which 45 (31%) were infected with three Onchocerca species (Onchocerca gutturosa, O. lienalis and an unidentified Onchocerca spp.), identified according to their morphological characteristics. Gross pathological examination of the teats with lesions revealed scabies and chaps of varying sizes, healed sores and small nodules. Histopathologically, large numbers of microfilariae were commonly observed within the collagenous fibre bundles of the dermis, with only a few microfilariae in the dermis in some cases. The microfilariae were also often found to have accumulated around the perivascular spaces and were frequently associated with infiltration by inflammatory cells, predominantly eosinophil leukocytes and mononuclear cells. In two cases, microfilariae were discovered exclusively in the lumen of the capillaries of the dermal papillaries. In one case, in which microfilarae were not encountered, sections of adult worms surrounded by neutrophil leukocytes were detected free in the teat canal. The presence of extensive teat lesions along with microfilariae of the Onchocerca species as found in this study warrants further assessment of the impact of onchocercosis on dairy farming.

Coccidia in the mammary glands of shrews (Order: Insectivora).

Three of 6 female long-clawed shrews, Sorex unguiculatus Dobson, 1890, collected on the island of Hokkaido, Japan, were found to have unsporulated oocysts and sexual stages (both macro- and microgamonts) in varying stages of development of an unidentified coccidium in both lactating and nonlactating mammary glands. Gamonts developed in the alveoli of the mammary glands, and oocysts were found in the lactiferous ducts and in pools of milk. Mature macrogamonts were 11.9 x 15.2 microm (10-14 x 14-20 microm), whereas completely developed microgamonts with many gametes were 14.8 x 16.8 microm (10-18 x 13-20 microm). Oocysts in tissue sections were 19.5 x 13.8 microm and had a smooth outer wall that was <1 microm thick. Little histopathology was associated with the infections. Infected cells were enlarged and appeared cloudy, and in some areas there was leucocytic infiltration by macrophages, small and large lymphocytes, neutrophils, and eosinophils. No basophil was seen. We also found sections of a nematode, probably a Mammanidula sp., in sections of an active mammary gland in 1 of the shrews not infected with the coccidium.

Udder cleft dermatitis and sarcoptic mange in a dairy herd.

OBJECTIVE: To determine prevalence of udder cleft dermatitis in a dairy herd that was experiencing an outbreak of sarcoptic mange. DESIGN: Clinical survey. ANIMALS: 1,597 Holstein cows and late-gestation heifers. PROCEDURE: Animals were examined for udder cleft dermatitis and for skin lesions consistent with sarcoptic or chorioptic mange. Skin scrapings were collected from 56 cows and examined for ectoparasites. The herd was revisited 1 year later, and prevalences of udder cleft dermatitis and lesions consistent with mange were determined in 506 cows. RESULTS: Of the 1,597 cattle examined, 280 (18%) had udder cleft dermatitis, and 1,397 (87.5%) had lesions consistent with mange. In 43 of 56 (77%) cows, skin scrapings revealed Sarcoptes mites. Udder cleft dermatitis was significantly more common in older than in younger cows. In first-lactation cows, udder cleft dermatitis was less common during the first 4 months of lactation than in the later stages of lactation, but udder cleft dermatitis was identified in cows in all stages of lactation and in cows that were not lactating. The herd was treated with eprinomectin to control mites, and prevalence of lesions consistent with mange 1 year later was only 2.8%. However, prevalence of udder cleft dermatitis was still 12%. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that cows in any stage of lactation and cows that are not lactating can have udder cleft dermatitis but that lesions are more common in older cows. Control of sarcoptic mange was accompanied by a moderate reduction in the prevalence of udder cleft dermatitis but did not eliminate the condition.

Isolation, characterisation and expression of mRNAs encoding the ovine CC chemokines, monocyte chemoattractant protein (MCP)-1alpha and -2.

CC chemokines are important mediators of immune responses, orchestrating the differential recruitment of various leukocyte populations. Despite the large number of known CC chemokines in other species, no cDNA encoding ovine CC chemokines have been isolated. A homology cloning strategy was utilised to isolate the cDNA of ovine CC chemokines. Full-length monocyte chemoattractant protein (MCP)-1alpha and -2 cDNA have been isolated. The predicted ovine MCP-1alpha amino acid sequence shares 87 and 75% identity with bovine MCP-1alpha and porcine MCP-1, respectively. The predicted ovine MCP-2 amino acid sequence shares 92 and 85% identity with bovine and porcine MCP-2, respectively. Northern blot analysis of MCP-1alpha revealed that it is strongly expressed in cells isolated from mammary lavage fluid (MAL) of ewes given intramammary infusions of Haemonchus contortus. Weak signals were detected in mammary and abomasal tissue. Southern blot analysis of reverse transcriptase-polymerase chain reaction (RT-PCR) products indicates that MCP-1alpha mRNA levels increase in abomasum after challenge with H. contortus. MCP-1alpha mRNA levels were also increased in bronchoalveolar lavage (BAL) cells and lung tissue after house dust mite extract (HDME) challenge. Similarly, MCP-2 mRNA was detected by Northern blot analysis at high levels in MAL cells after H. contortus intramammary infusion, and increased in BAL cells and lung tissue in HDME-challenged sheep. MCP-2 mRNA was not detected by Northern blots in whole mammary or abomasal tissue, but Southern blot analysis of RT-PCR products also indicates that MCP-2 mRNA increases in abomasal tissue after challenge with H. contortus. Hence, two ovine CC chemokine mRNA have been isolated that are up-regulated in response to parasite infection and allergen challenge. Ultimately the isolation of these and other ovine CC chemokines will help elucidate a wide variety of immune responses in sheep.

Invasion of West African cattle by the tick Amblyomma variegatum.

Studies in Cameroon and Burkina Faso examined the invasion process of cattle by adult Amblyomma variegatum Fabricius (Acari: Ixodidae) ticks. Nearly all the ticks picked up in the pasture during grazing were found on the limb ends, near the hooves, where they temporarily attached. Then when the cattle lay down, the ticks moved from the feet towards the predilection sites, where they attached definitively. Many ticks disappeared during this displacement. All the female ticks and approximately 70% of the males were thus unable to attach to the predilection sites as long as the pioneer males had not attached and started to produce attraction-aggregation-attachment pheromones. Nevertheless, A. variegatum females and males attached to the feet in similar numbers during grazing, whether the cattle were already infested or not, indicating that stimuli originating from the hosts are powerful enough to attract both sexes. After attachment of the pioneer males, the number of ticks that successfully reached the predilection sites increased. However, even on infested animals, 40-50% of A. variegatum ticks found near the hooves after the grazing periods disappeared during the night following their capture. When moving from the temporary attachment sites towards the final ones, one-third of the ticks changed the individual host. Considering this two-stage infestation process, it is suggested that a targeted tick control, using a foot-bath, might greatly reduce cattle infestation. In particular, it could be effective in traditional herds, with animals grazing permanently during the day, lying down only once back in the night pen.