Diagnostic tools of caprine and ovine anaplasmosis: a direct comparative study

Molecular epidemiology of anaplasmosis in Indian dromedary camels

The present study aimed to investigate the molecular epidemiology, risk factors, and haemato-biochemical changes in anaplasmosis in Indian dromedary camels. Blood samples collected from 103 camels were analysed using blood smear examination and semi-nested PCR based on the 16s rRNA gene to diagnose anaplasmosis. The prevalence of anaplasmosis was estimated to be 42.72% (95% CI: 33.59-52.37) by PCR assay and 16.5% (95% CI: 10.47-24.95%) by blood smear examination. Phylogenetic analysis of six partial sequences of 16s rRNA gene obtained in the present study indicated the involvement of multiple Anaplasma species, including A. marginale and A. platys, showing genetic similarity with cattle strains. A novel genotype related to A. camelii/A. cinensis/A. platys group was also identified. Hemato-biochemical examination revealed mild anaemia, increased serum urea nitrogen and creatinine levels, and decreased total protein and albumin levels in Anaplasma-positive animals. The infections were largely subclinical in nature, except in one camel that revealed fever, inappetence, and pale mucous membrane and responded well to treatment with oxytetracycline. To our knowledge, this is the first molecular study on camel anaplasmosis in India, indicating a high prevalence of infection and involvement of multiple Anaplasma species with potential risk for interspecies transmission.

Molecular detection and associated risk factors of Anaplasma marginale, A. ovis and A. platys in sheep from Algeria with evidence of the absence of A. phagocytophilum

Anaplasma species are obligate intracellular rickettsial pathogens that cause significant diseases in animals and humans. Despite their importance, limited information on Anaplasma infections in Algeria has been published thus far. This study aimed to assess the infection rate, characterize Anaplasma species, and identify associated risk factors in selected sheep farms across Oum El Bouaghi region in Algeria. In 2018, we collected 417 blood samples from sheep (Ovis aries) and performed molecular characterization of Anaplasma species infecting these animals. This characterization involved the use of 16S rRNA, msp2, rpoB, and msp5 genes, which were analyzed through nested PCR, qPCR, cPCR, DNA sequencing, and subsequent phylogenetic analysis. Our findings revealed infection rates of 12.7 % for Anaplasma species detected, with Anaplasma ovis at 10.8 %, Anaplasma marginale at 1.7 %, and Anaplasma platys at 0.2 %. Interestingly, all tested animals were found negative for Anaplasma phagocytophilum. Statistical analyses, including the Chi-square test and Fisher exact test, failed to establish any significant relationships (p > 0.05) between A. ovis and A. platys infections and variables such as age, sex, sampling season, and tick infestation level. However, A. marginale infection exhibited a significant association with age (p < 0.05), with a higher incidence observed in lambs (5.2 %) compared to other age groups. Remarkably, this study represents the first molecular detection of A. platys and A. marginale in Algerian sheep. These findings suggest that Algerian sheep may serve as potential reservoirs for these pathogens. This research contributes valuable insights into the prevalence and characteristics of Anaplasma infections in Algerian sheep populations, emphasizing the need for further investigation and enhanced surveillance to better understand and manage these diseases.

Molecular prevalence and associated infection risk factors of tick-borne protozoan and rickettsial blood pathogens in small ruminants

BACKGROUND

Tick-borne blood pathogens cause highly pathogenic diseases, which are associated with substantial economic losses in ruminants. Despite this, epidemiological research on these pathogens remains neglected in many countries. This study initiated a regional epidemiological survey that included the detection of molecular prevalence, associated risk factors, and gene sequencing, combined with phylogenetic analysis, targeting the two main tick-borne blood protozoan and rickettsial pathogens of Babesia, Theileria, and Anaplasma that infect small ruminants. One hundred blood samples were collected from 76 sheep and 24 goats.

RESULTS

Microscopic examination of Giemsa-stained blood films revealed that 73% of the samples were infected with at least one species of the three blood pathogenic organisms. Molecular diagnosis based on the 18 S rRNA for Babesia and Theileria species and the major surface protein 4 (msp4) for Anaplasma species, revealed that 43% of the small ruminants were infected with at least one of these pathogens. The animal's sex was the most significant associated risk factor, with 49.4% of female animals infected compared with only 4% of male animals (P < 0.05). The open breeding system recorded the highest infection rate for tick-borne blood pathogens. Homology-based and phylogenetic analyses indicated that the specific isolate species were Babesia ovis (B. ovis), Theileria ovis (T. ovis), and Anaplasma ovis (A. ovis), with sequences showing significant identities with isolates from sheep, goats, and other animal species, and geographically diverse countries in Africa, Asia, and Europe, in addition to Egypt.

CONCLUSION

This was the first molecular evidence of B. ovis, T. ovis, and A. ovis infections in sheep and goat populations in the North Coast region of Egypt. More extensive studies are required to develop an epidemiological map of blood pathogenic organisms, while more effective control strategies are required to reduce the burden of tick-borne pathogens on small ruminants.

Co-exposure to Anaplasma spp., Coxiella burnetii and tick-borne encephalitis virus in sheep in southern Germany

The intracellular bacteria Anaplasma spp. and Coxiella burnetii and the tick-borne encephalitis virus (TBEV) are tick-transmitted pathogens circulating in the southern German sheep population. Knowledge of interaction among Anaplasma spp., C. burnetii and TBEV in sheep is lacking, but together they might promote and reinforce disease progression. The current study aimed to identify co-exposure of sheep to Anaplasma spp., C. burnetii and TBEV. For this purpose, 1,406 serum samples from 36 sheep flocks located in both southern German federal states, Baden-Wuerttemberg and Bavaria, were analysed by ELISAs to determine the antibody levels of the three pathogens. Inconclusive and positive results from the TBEV ELISA were additionally confirmed by a serum neutralisation assay. The proportion of sheep with antibodies against Anaplasma spp. (47.2%), C. burnetii (3.7%) and TBEV (4.7%) differed significantly. Significantly more flocks with Anaplasma spp. seropositive sheep (91.7%) were detected than flocks with antibodies against TBEV (58.3%) and C. burnetii (41.7%), but there was no significant difference between the number of flocks which contained TBEV and C. burnetii seropositive sheep. Seropositivity against at least two pathogens was detected in 4.7% of sheep from 20 flocks. Most co-exposed sheep had antibodies against Anaplasma spp./TBEV (n = 36), followed by Anaplasma spp./C. burnetii (n = 27) and Anaplasma spp./C. burnetii/TBEV (n = 2). Only one sheep showed an immune response against C. burnetii and TBEV. Flocks with sheep being positive against more than one pathogen were widely distributed throughout southern Germany. The descriptive analysis revealed no association between the antibody response of the three pathogens at animal level. Taking the flocks as a cluster variable into account, the exposure to TBEV reduced the probability of identifying C. burnetii antibodies in sheep significantly (odds ratio 0.46; 95% confidence interval 0.24-0.85), but the reason for this is unknown. The presence of Anaplasma spp. antibodies did not influence the detection of antibodies against C. burnetii and TBEV. Studies under controlled conditions are necessary to evaluate any possible adverse impact of co-exposure to tick-borne pathogens on sheep health. This can help to clarify rare disease patterns. Research in this field may also support the One Health approach due to the zoonotic potential of Anaplasma spp., C. burnetii and TBEV.

Natural Co-Exposure to Borrelia burgdorferi s.l. and Anaplasma phagocytophilum: Unraveling the Hematological Profile in Sheep

The occurrence of co-infected hosts and questing ticks with more than one tick-borne pathogen-as in the case of Anaplasma phagocytophilum and Borrelia burgdorferi sensu lato-is expected in endemic regions. Their synergy-in terms of pathogenesis and disease severity-has been suggested previously in humans. Limited data exist on the clinicopathological alterations in co-infected sheep. In this study, we investigated the impact of A. phagocytophilum and B. burgdorferi s.l. seropositivity, alone and in combination, on the hematological parameters of naturally infected sheep. A complete blood count was performed, and indirect immunofluorescence assays were used to detect IgG antibodies against A. phagocytophilum and IgG and IgM antibodies against B. burgdorferi s.l. Single natural exposure to B. burgdorferi s.l. was characterized by low Packed Cell Volume (PCV) values and platelet (PLT) counts, while single exposure to A. phagocytophilum was characterized by low PCV values, low white blood cell (WBC) counts, and an increased risk for leukopenia and neutropenia. Co-exposure resulted in the most severe blood abnormalities; all the blood parameters decreased, and the sheep presented an increased risk for anemia. Our study showed that natural co-exposure to A. phagocytophilum and B. burgdorferi s.l. in sheep leads to more severe blood abnormalities and enhances the pathogenic processes. More studies are needed to clarify the possible background mechanisms.

Multiple blood pathogen infections in apparently healthy sheltered dogs in southern Thailand

In developing countries such as Thailand, free-ranging dogs are frequently involved in road accidents and contribute to the cost of public healthcare. Shelters play a vital role in communities because they help to control the population of unwanted and free-ranging dogs. This study aimed to investigate blood pathogen infection in sheltered dogs, as it is one of the factors contributing to animal welfare. Blood samples were randomly collected from 141 dogs from the largest shelter (approximately 400–500 dogs in total) in southern Thailand. Blood pathogens were detected using both PCR and light microscopy. Four blood pathogens were identified: Anaplasma platys, Ehrlichia canis, Babesia canis vogeli, and Hepatozoon canis. No trypanosomes were detected. The incidence of blood parasite infection was 56.7% (80/141) by PCR, and 28.4% (40/141) by microscopy. E. canis was the most prevalent pathogen, accounting for 46.1% (65/141) of the cases, while multiple infections accounted for 22% (31/141) of the cases. A triple infection with E. canis, A. platys, and B. canis vogeli was observed in 5.7% (8/141) of the cases. Although PCR is far more sensitive than microscopy, it appears to have equivalent specificity. In conclusion, this study reported a high occurrence of blood pathogen infections in clinically healthy sheltered dogs. Many of them were infected with multiple pathogens and may have been infected before entering the shelter. These findings suggest that a blood test is necessary to screen dogs prior to their admission to the shelter to prevent disease transmission and enhance animal welfare.

Anaplasma ovis Prevalence Assessment and Cross Validation Using Multiparametric Screening Approach in Sheep from Central Tunisia

We conducted a 5-month-long screening of Anaplasma spp. and Anaplasma ovis infection in sheep from central Tunisia. During this longitudinal study, we investigated the infection dynamics using both direct and indirect assessments validated with a polymerase chain reaction (PCR) as the gold standard method. The experimental design included 84 male lambs aged from 6 to 8 months, and 32 ewes, both chosen randomly from June to November with a periodicity of 2 weeks approximately between June and September, and 1 month between September and November. A total of 9 field visits were carried out in this period during which animals were clinically examined and biological samples were extracted. Thus, a total of 716 blood smears, 698 sera from the nine sampling dates, as well as 220 blood samples from the first and the ninth sampling dates were collected from apparently healthy lambs and ewes, respectively, and analyzed by competitive enzyme-linked immunosorbent assay (cELISA) and polymerase chain reaction (PCR) assay, for the detection of Anaplasma antibodies and A. ovis DNA, respectively. Sera were analyzed by competitive enzyme-linked immunosorbent assay (cELISA) and PCR, for the detection of Anaplasma antibodies and A. ovis DNA, respectively. The Anaplasma spp. initial seroprevalence rate was 33.3% in lambs and 100% in ewes, and it then flowed in an upward trend to reach a maximum of 52.6% in lambs, whereas in ewes, the Anaplasma spp. seroprevalence rate remained unchanged and equal to 100%. Meanwhile, the A. ovis initial molecular prevalence was 22.6% at the first visit and 26.3% at the last visit in lambs, whereas in ewes, the molecular prevalence rates of A. ovis were higher in both the first and the last visit estimated at 100% and 85.7%, respectively. The Kappa coefficient between cELISA and PCR indicated a moderate level of agreement on the first sampling date (0.67) and a low agreement level on the last (0.43). Furthermore, an exploratory data analysis using a multimodal machine learning approach highlighted the underlying pattern of each analytical technique used in this study. In this prospect, we were able to establish the performance of each technique at detecting Anaplasma spp. in sheep. The combination of these approaches should improve the field assessment while promoting a data-based decision in precision epidemiology. The genetic follow-up test relevant to A. ovis msp4 sequences revealed three different genotypes, two of which were previously described in Italy.

Molecular Survey and Genetic Characterization of Anaplasma marginale in Ticks Collected from Livestock Hosts in Pakistan

Simple Summary

Ticks transmit different disease-causing agents to humans and animals. Pakistan is an agricultural country, the rural economy mainly relies on livestock farming, and tick infestation is a severe constraint to its livelihood. The genus Anaplasma comprises obligate Gram-negative intracellular bacteria multiplying within the host cells and can be transmitted to humans and animals through the tick vector. The current study aimed to molecularly characterize the Anaplasma spp. in hard ticks infesting livestock in different districts of Khyber Pakhtunkhwa, Pakistan. The present study reported nine species of hard ticks infesting different hosts. The most prevalent tick life stage was adult females, followed by nymphs and adult males. In the phylogenetic tree, 16S rDNA sequences of Anaplasma spp. clustered with sequences of A. marginale. The hard ticks act as a carrier for the transmission of A. marginale. Further extensive country-wide research is required to explore the diverse tick species and the associated pathogens in Pakistan.

Abstract

Ticks transmit pathogens to animals and humans more often than any other arthropod vector. The rural economy of Pakistan mainly depends on livestock farming, and tick infestations cause severe problems in this sector. The present study aimed to molecularly characterize the Anaplasma spp. in hard ticks collected from six districts of Khyber Pakhtunkhwa, Pakistan. Ticks were collected from various livestock hosts, including cattle breeds (Holstein-Friesian, Jersey, Sahiwal, and Achai), Asian water buffaloes, sheep, and goats from March 2018 to February 2019. Collected ticks were morphologically identified and subjected to molecular screening of Anaplasma spp. by amplifying 16S rDNA sequences. Six hundred seventy-six ticks were collected from infested hosts (224/350, 64%). Among the nine morphologically identified tick species, the highest occurrence was noted for Rhipicephalus microplus (254, 37.6%), followed by Hyalomma anatolicum (136, 20.1%), Rhipicephalus haemaphysaloides (119, 17.6%), Rhipicephalus turanicus (116, 17.1%), Haemaphysalis montgomeryi (14, 2.1%), Hyalomma dromedarii (11, 1.6%), Haemaphysalis bispinosa (10, 1.5%), Hyalomma scupense (8, 1.2%), and Haemaphysalis kashmirensis (8, 1.2%). The occurrence of tick females was highest (260, 38.5%), followed by nymphs (246, 36.4%) and males (170, 25.1%). Overall, the highest occurrence of ticks was recorded in the Peshawar district (239, 35.3%), followed by Mardan (183, 27.1%), Charsadda (110, 16.3%), Swat (52, 7.7%), Shangla (48, 7.1%), and Chitral (44, 6.5%). Among these ticks, Anaplasma marginale was detected in R. microplus, R. turanicus, and R. haemaphysaloides. The 16S rDNA sequences showed high identity (98–100%) with A. marginale reported from Australia, China, Japan, Pakistan, Thailand, Uganda, and the USA. In phylogenetic analysis, the sequence of A. marginale clustered with the same species reported from Australia, China, Pakistan, Thailand, Uruguay, and the USA. Further molecular work regarding the diversity of tick species and associated pathogens is essential across the country.

Evaluation of an Indirect Immunofluorescence Assay for the Detection of Anaplasma phagocytophilum Antigen in Ovine Buffy Coat Smears

Diagnosis of anaplasmosis is challenging considering the great variation in clinical signs and the limitations of the available diagnostic assays, while the detection of carrier animals that play a significant role in disease epidemiology as reservoirs is of great significance. In this study, we evaluated the diagnostic accuracy of a newly developed indirect immunofluorescent assay (Ag-IFAT) for the detection of A. phagocytophilum antigens in buffy coat specimens, alone and in combination with cytology, using PCR as a reference. Blood samples were collected from 138 sheep of the Chios breed from six farms in Greece. A buffy coat was extruded from the centrifuged blood. Buffy coat smears were used for cytological examination and the Ag-IFAT assay. The Ag-IFAT assay presented excellent specificity (100%) and high sensitivity (85.4%) for the detection of A. phagocytophilum antigens in buffy coats, and it has an almost perfect agreement with PCR and cytology (κ value = 0.88 and 0.85, respectively). A. phagocytophilum antigens are likely to be detected using Ag-IFAT in a PCR-positive animal, as indicated by the good performance of the assay. Overall, this assay presents high diagnostic accuracy, and it could be used for the detection of animals during the early stage of infection.

Anaplasma phagocytophilum and Anaplasma ovis-Emerging Pathogens in the German Sheep Population

Knowledge on the occurrence of pathogenic tick-borne bacteria Anaplasma phagocytophilum and Anaplasma ovis is scarce in sheep from Germany. In 2020, owners from five flocks reported ill thrift lambs and ewes with tick infestation. Out of 67 affected sheep, 55 animals were clinically examined and hematological values, blood chemistry and fecal examinations were performed to investigate the underlying disease causes. Serological tests (cELISA, IFAT) and qPCR were applied to all affected sheep to rule out A. phagocytophilum and A. ovis as a differential diagnosis. Ticks were collected from selected pastures and tested by qPCR. Most animals (n = 43) suffered from selenium deficiency and endoparasites were detected in each flock. Anaplasma spp. antibodies were determined in 59% of examined sheep. Seventeen animals tested positive for A. phagocytophilum by qPCR from all flocks and A. phagocytophilum was also detected in eight pools of Ixodes ricinus. Anaplasma phagocytophilum isolates from sheep and ticks were genotyped using three genes (16S rRNA, msp4 and groEL). Anaplasma ovis DNA was identified in six animals from one flock. Clinical, hematological and biochemical changes were not significantly associated with Anaplasma spp. infection. The 16S rRNA analysis revealed known variants of A. phagocytophilum, whereas the msp4 and groEL showed new genotypes. Further investigations are necessary to evaluate the dissemination and health impact of both pathogens in the German sheep population particularly in case of comorbidities.

Seroprevalence and Risk Factors of Anaplasma spp. in German Small Ruminant Flocks

Knowledge about the distribution of Anaplasma spp. in small ruminants from Germany is limited. Therefore, serum samples were examined from 71 small ruminant flocks (2731 sheep, 447 goats) located in the five German federal states: Schleswig-Holstein (SH), Lower Saxony (LS), North Rhine-Westphalia (NRW), Baden-Wuerttemberg (BW) and Bavaria (BAV). Antibodies to Anaplasma spp. were determined by a cELISA based on the MSP5 antigen. A risk factor analysis at animal and flock level was also performed. Antibodies to Anaplasma spp. were detected in 70/71 flocks without significant difference in the intra-flock prevalence (IFP) between the federal states. The mean antibody levels from sheep were significantly lower in northern Germany (LS, SH) compared to west (NRW) and south Germany (BW, BAV). Sheep had a 2.5-fold higher risk of being seropositive than goats. Females and older animals (>2 years) were more likely to have antibodies to Anaplasma spp. in one third and one quarter of cases, respectively. Flocks used for landscape conservation had a five times higher risk of acquiring an IFP greater than 20%. Cats and dogs on the farms increased the probability for small ruminant flocks to have an IFP of above 20% 10-fold and 166-fold, respectively. Further studies are necessary to assess the impact of Anaplasma species on the health of small ruminants in Germany.

Hematologic Conditions of Small Ruminants

Anemia is a clinically important syndrome in small ruminants. Anemia can be divided into regenerative and nonregenerative forms. Differentials for regenerative anemia include hemorrhage owing to gastrointestinal or external parasitism or hemostatic disorders, and hemolysis owing to infectious, osmotic, toxic, and nutritional causes. Differentials for nonregenerative anemia include inflammatory and chronic diseases, renal failure, pancytopenia, copper deficiency, and heavy metal toxicosis. Iron deficiency anemia can be caused by chronic gastrointestinal and external hemorrhage or nutritional deficiency and may be mildly regenerative or nonregenerative. Appropriate diagnostic tests are described along with treatments, including blood transfusion, parasite control, and prevention.

Quantitative and Morphological Blood Cell Findings Associated with the Presence of Antigen and/or Antibodies Against Anaplasma phagocytophilum in Sheep

Anaplasma phagocytophilum is the causative agent of a disease known as tick borne fever in sheep, although fever is not always present. Due to inconclusive clinical signs, diagnosis is based on the cytological or molecular detection of the microorganism in blood and/or the determination of antibodies against A. phagocytophilum. The aim of the study was to determine the alterations caused by the presence of antibodies and/or the antigen of A. phagocytophilum in the blood cell count and morphology in sheep. Cytology and indirect immunofluorescence assay were performed for detection of antibodies and the antigen of A. phagocytophilum, respectively. The samples were divided into four groups depending on the result of the antigen and antibody detection. The samples that were only positive for antigen detection had mild anemia, leukopenia (lymphopenia), and thrombocytopenia. The samples that were positive in both assays had anemia, leukopenia (neutropenia and lymphopenia), and thrombocytopenia. Samples that were positive only for antibody detection had mild leukopenia. Morphological findings in infected sheep included band neutrophils, toxic neutrophils, reactive lymphocytes, and activated monocytes. The hematological findings along with cytological and serological tests can contribute to the assessment of the stage of the disease. A combination of leukopenia and thrombocytopenia raises a strong suspicion of the disease. When the microorganism and antibodies are simultaneously present, sheep are more susceptible to secondary complications. The first reported morphological findings and the quantitative hematological alterations are indicative of an inflammatory reaction, antigenic stimulation, and stress.

Molecular prevalence, characterization and associated risk factors of Anaplasma spp. and Theileria spp. in small ruminants in Northern Pakistan

This study was conducted in four districts (Malakand, Swat, Bajaur and Shangla) of Northern Pakistan to investigate the prevalence, associated risk factors and phylogenetic analyses of Theileria and Anaplasma species in small ruminants. A total of 800 blood samples, 200 from each district, were collected from apparently healthy animals. PCR assays were performed using generic primers for Anaplasma spp. and Theileria spp. as well as species specific primers for A. ovis and T. ovis. Overall infection prevalence was 361/800 (45.1%). Theileria spp. infection prevalence (187/800, 23.3%) was higher than Anaplasma spp. (174/800, 21.7%). Amplified partial 18S rRNA genes were sequenced and enrolled animals were found to be infected by T. ovis (115/800, 14.3%), and at least two more Theileria species (72/800, 9%) were present (T. lestoquardi and T. annulata). All blood samples that were found to be positive for Anaplasma spp. were also positive for A. ovis. Infection prevalence was higher in sheep (227/361, 28.3%) compared to goats (134/361, 16.6%) (p < 0.005). Univariable analysis of risk factors showed that host, age, grazing system and acaricide treatment were significant determinants (p < 0.05) for both Theileria and Anaplasma infections. Multivariable analysis revealed that host, sex, age, tick infestation and grazing system were significant risk factors (p < 0.005) for both pathogens. Phylogenetic analysis revealed variants among the A. ovis and T. annulata samples analysed, indicating that different genotypes are circulating in the field while T. ovis presented the same genotype for the samples analysed.

Systematic Review of Ticks and Tick-Borne Pathogens of Small Ruminants in Pakistan

Ticks and tick-borne diseases (TTBDis) are a major constraint to the health and production of small ruminants in Pakistan. Despite being the subject of intermittent studies over the past few decades, comprehensive information on the epidemiology and control of TTBDis is lacking. Herein, we have systematically reviewed the current knowledge on TTBDis of small ruminants in Pakistan. Critical appraisal of the selected 71 articles published between 1947 to 2020 revealed that morphological examination had been the most widely used method for the identification of TTBDis in Pakistan. Tick fauna comprise at least 40 species, mainly belonging to Haemaphysalis, Hyalomma and Rhipicephalus. The prevalence of ticks is the highest in summer (June–September) and it is also higher in goats than sheep. Anaplasma, Babesia and Theileria spp. are the major tick-borne pathogens (TBPs), and their prevalence is usually higher in sheep than goats. Spatio-temporal distribution, genetic diversity and control of ticks and TBPs of small ruminants as well as the competence of tick vectors for various TBPs remain to be explored. Therefore, coordinated and focused investigations are required to fill knowledge gaps in these areas to maximise the health, production and welfare of small ruminants and minimise economic losses associated with TTBDis in Pakistan.

Clinical signs, prevalence, and hematobiochemical profiles associated with Anaplasma infections in sheep of North Iraq

Background and Aim:

Anaplasma infection is a worldwide prevalent condition that causes significant economic losses in affected flocks. This study was conducted to determine the prevalence and clinical signs associated with ovine anaplasmosis as well as the hematological and biochemical changes associated with the disease in natural infection in North Iraq.

Materials and Methods:

A total of 420 sheep were appropriately examined, and the clinical signs were documented accordingly. Blood samples were collected and subjected to parasitological, hematological, and biochemical analyses.

Results:

Anaplasma-infected sheep displayed the following clinical signs: Paleness of the mucous membrane, bloody diarrhea, emaciation, pyrexia, jaundice, nasal discharge, coughing, loss of wool, nervous signs, hemoglobinuria, and lacrimation. The prevalence of Anaplasma infection was 66.19%, and female sheep were significantly (p<0.05) more infected than male sheep. The hematological and biochemical parameters were significantly different between Anaplasma-positive and Anaplasma-negative sheep.

Conclusion:

Anaplasma infection among sheep is a significant concern in North Iraq considering its prevalence, clinical signs, and hematological and biochemical findings, which entirely causes significant debilitating effects on sheep productivity. It is important to pay more attention toward managing tick infestation among sheep to reduce the occurrence of this rickettsial disease for a more robust livestock sector of the Iraqi economy.

Bovine ticks harbour a diverse array of microorganisms in Pakistan

BACKGROUND

Ticks and tick-borne pathogens (TTBP) are a major constraint to livestock production in Pakistan; despite a high prevalence of TTBPs, knowledge on the capacity of Pakistani ticks to carry pathogens and endosymbionts is limited. Furthermore, mixed infections with multiple microorganisms further complicate and limit the detection potential of traditional diagnostic methods. The present study investigated the tick-borne microorganisms in bovine ticks in Pakistan, employing a high-throughput microfluidic real-time PCR based technique.

METHODS

Ticks were collected from clinically healthy cattle (n = 116) and water buffaloes (n = 88) from 30 villages across six districts located in five agro-ecological zones (AEZs) of Pakistan from September to November 2017. The microfluidic real-time PCR was used to test the genomic DNA of individual ticks for the presence of 27 bacterial and eight parasitic microorganisms. Phylogenetic methods were used to assess the genetic relationship of DNA sequences determined herein.

RESULTS

PCR detected DNA of at least one microorganism in each of 221 ticks tested (94.4%, 221/234). DNA-based detection inferred that single pathogens/endosymbionts were the most common (43.4%, 96/221) followed by double (38.9%, 86/221), triple (14.5%, 32/221), quadruple (2.3%, 5/221) and quintuple (0.9%, 2/221) mixed infections. Piroplasms (Babesia/Theileria spp.) were the most prevalent (31.6%, 74/234), followed by Ehrlichia spp. (20%, 47/234) and Anaplasma marginale (7.7%, 18/234). Anaplasma phagocytophilum, A. ovis, A. centrale, Babesia ovis, Borrelia spp., Rickettsia spp., R. massiliae, Bartonella spp. and Hepatozoon spp. were also detected. Endosymbionts such as Francisella-like (91.5%, 214/234) and Coxiella-like (1.3%, 3/234) organisms were also detected in ticks. The highest diversity of microorganisms was detected in Hyalomma anatolicum ticks (test-positive for 14/14 microorganisms), followed by Rhipicephalus microplus (4/14), Hy. hussaini (3/14) and Rh. annulatus (2/14). Ticks collected from cattle carried significantly more frequently piroplasms (41.2%, 54/131; P < 0.05) than those from buffaloes (19.4%, 20/103). However, the overall prevalence of microorganisms did not vary significantly among ticks from the two host species as well as across different AEZs.

CONCLUSIONS

To our knowledge, this is the first study to investigate a wide range of tick-borne microorganisms in bovine ticks using a high-throughput diagnostic method from different AEZs in Pakistan. These findings will aid in establishing the distribution patterns and the control of tick-borne pathogens of bovines in Pakistan.