First Report on Molecular Characterization of Anaplasmosis in Small Ruminants in Pakistan

On-farm epidemiology, virulence profiling, and molecular characterization of methicillin-resistant Staphylococcus aureus at goat farms

Antimicrobial resistance (AMR) becomes a challenging issue that limits the therapeutic options for both veterinary and public health professionals. The current study aimed to investigate the on-farm epidemiology, antibiotics resisting profiling, virulence analysis, and molecular detection of methicillin-resistant Staphylococcus aureus (MRSA) at the caprine-human interface. A total of 768 goat milk samples and 94 skin swabs from farm personnel were collected from 30 goat flocks and processed for isolation of S. aureus. The study isolates were confirmed as MRSA based on the oxacillin and cefoxitin disc diffusion test and the presence of mecA gene. MRSA isolates of goats and human origin were characterized and further evaluated for the presence of virulence genes responsible for intramammary infections and public health hazards. The results revealed 26.82 % and 27.79 % goat milk samples and human samples positive for S. aureus, respectively. A higher MRSA prevalence of 35.92 % and 10.71 % was found in goat and human isolates respectively. The phylogenetic analysis revealed a lesser extent of homology in mecA gene of S. aureus isolates at the caprine-human interface. Moreover, this study revealed strong evolutionary connection between the study isolates and MRSA isolates of Pakistani cattle and buffalo while the in-silico protein analysis showed that all sequences have the same protein motifs resembling penicillin binding protein 2a. The risk factors analysis revealed that teat length, drainage system, hygienic measures during milking, use of teat dip, teat injury, and veterinary services were significantly associated with subclinical mastitis in goats. A total of 43.24 % of local MRSA isolates showed multi-drug resistance (MDR). The isolates showed higher resistance to oxytetracycline followed by gentamicin and vancomycin while moxifloxacin, and linezolid were among the susceptible antibiotics. Local MRSA isolates carried virulence markers (nuc and coag genes) and biofilm-associated icaA (43.24 %) and icaD (29.73 %) genes which are responsible for the intramammary infection. The local isolates also carried the virulence genes of public health concern including the enterotoxin C (sec) gene (24.3 %), enterotoxins B (seb) gene (5.41 %), and enterotoxin D (sed) gene (2.7 %). Enterotoxins A (sea) and E (see) genes were not detected in any isolate. The study concluded that MRSA is an emerging and prevailing pathogen in dairy goats with a high potential to transmit to associated human beings. The presence of a variety of virulence factors as well as the associated antibiotic resistance makes MRSA a potential threat at animal-human interface and thus demands further research.

Molecular prevalence and phylogeny of Anaplasma marginale, Anaplasma ovis and Theileria ovis in goats and sheep enrolled from a hill station in Punjab, Pakistan

Anaplasma marginale (A. marginale), Anaplasma ovis (A. ovis) and Theileria ovis (T. ovis) are among the most commonly reported intracellular tick borne pathogens that infect ruminants across the globe causing huge economic losses. This study aims to report the prevalence and phylogenetic evaluation of these three pathogens infecting sheep and goats (n = 333) that were enrolled from Fort Munro region in Pakistan by using msp1b, msp4 and 18S rRNA genes for A. marginale, A. ovis and T. ovis respectively. Results revealed almost similar infection rates in sheep and goats with an overall prevalence of 11% for A. marginale, 28% for A. ovis and 3% for T. ovis. Concurrent infection was also recorded, however, the number of animals infected with two pathogens (n = 24; 7.2%) was higher than infection with three pathogens (n = 2; 0.6%). Risk factor analysis revealed that sheep reared in small herds had higher A. marginale (P = 0.03) and A. ovis (P = 0.04) infection rates compared to those from large herds. In addition, it was observed that bucks (P ≤ 0.05) and tick-free goats (P ≤ 0.05) exhibited higher A. ovis infection rates than nannies. Phylogenetic analysis of all three pathogens showed that Pakistani isolates were clustered together and were closely related to previously deposited Pakistani isolates as well as with those that were reported from worldwide countries. In conclusion, we are reporting that Pakistani sheep and goats have A. marginale, A. ovis and T. ovis mediated infections and control measures should be taken against them to improve the productivity of the livestock sector.

Epidemiology and Phylogeny of Anaplasma ovis with a Note on Hematological and Biochemical Changes in Asymptomatic Goats Enrolled from Four Districts in Punjab, Pakistan

Background: Anaplasma ovis is an intra-erythrocytic gram negative rickettsial bacterium that infects small ruminants, resulting in huge economic losses worldwide. Materials and Methods: The present investigation aims at reporting the molecular prevalence of A. ovis in 1200 asymptomatic goats that were enrolled from 4 districts (Layyah, Lohdran, Dera Ghazi Khan, and Rajanpur) in Punjab, Pakistan by targeting the msp4 gene of bacterium. Risk factors associated with the prevalence of A. ovis and phylogeny of bacterium were also documented. Results: 184 out of 1200 (15%) goat blood samples were infected with A. ovis. The prevalence of the pathogen varied with the sampling sites (p = 0.005), and the highest prevalence was detected in goats from Layyah (19%) followed by Rajanpur (17%), Dera Ghazi Khan (15%), and Lohdran district (9%). The represented partial msp4 gene amplicon was confirmed by Sanger sequencing and deposited to GenBank (OP225957-59). Phylogenetic analysis revealed that the amplified isolates resembled the msp4 sequences reported from Iran, Mangolia, Sudan, and the United States. Sex and age of goats, herd composition and size, and the presence of ticks on goats and dogs associated with herds were the rick factors associated with the prevalence of A. ovis. Red blood cells, lymphocytes (%), neutrophils (%), hemoglobin, and hematocrit levels in blood and Aspartate amino transferase, urea, and creatinine levels in serum were disturbed in A. ovis infected goats when compared with uninfected animals. Conclusion: We are reporting the prevalence of A. ovis in Pakistani goats from four districts of Punjab and these data will help in developing the integrated control policies against this tick-borne pathogen that is infecting our goat breeds.

Molecular Epidemiology, Seasonality and Phylogenetic Investigations of Anaplasma ovis in Small Ruminants from Diverse Agro-Climatic Regions of Punjab, Pakistan

Anaplasma (A.) ovis is the most important cause of anaplasmosis in small ruminants. The current study was planned to estimate the molecular prevalence, risk factors, and phylogenetic analysis of A. ovis infection in sheep and goats from different agro-climatic regions of Central and Southern Punjab, Pakistan. A total of 400 jugular blood samples were collected from asymptomatic goats (n = 200) and sheep (n = 200) from the Jhang and Dera Ghazi Khan districts from January 2021 to February, 2023. Two hundred blood samples were collected from each district. Ten union councils (UC) were randomly chosen from each district, and 20 samples were collected from each UC based on the multistage cluster sampling technique. The samples were analyzed with PCR targeting the major surface protein (msp4) gene of A. ovis. The overall molecular prevalence of anaplasmosis was 57.5%. The disease occurrence was higher in Dera Ghazi Khan (61.5%) than in the Jhang district (53.5%). Infection positivity was greater in goats (65.5%) than in sheep (49.5%). Multivariate logistic regression analysis indicated that host species [sheep; Odds Ratio (OR) = 3.212; p = 0.000, Confidence Interval (CI) = 1.968-5.242], age (adult; OR = 2.606; p = 0.003, CI = 1.398-4.858), and acaricide use (never; OR = 13.671; p = 0.000, CI = 6.414-26.283) were significantly higher risk for A. ovis in small ruminants (p< 0.05; OR > 1). The sequencing and phylogenetic analysis of four representative isolates in the current study (Genbank numbers; Goats: OQ302202, OQ302203; Sheep: OQ319592, OQ319593) revealed novel strains of A. ovis with 97-100% similarity from different countries. The msp4-based goat isolates showed greater genetic diversity, while sheep genotypes showed homology with isolates from Italy, Spain, Hungary, Cyprus, Spain, Iran, and China. The current surveillance study will help in devising prevention and control strategies regarding anaplasmosis in small ruminants. However, there is a need for further study on the clinicopathological and vector competence aspects of these genotypes.

Molecular Evidence and Hematological Profile of Bovines Naturally Infected with Ehrlichiosis in Southern Punjab, Pakistan

PURPOSE

Ehrlichiosis is one of the tick-borne diseases, which is not only neglected in Pakistan but only a few reports have been documented throughout the globe. The purpose of this study is to highlight and report the neglected pathogen from bovines in Pakistan.

METHODS

In this study, the pathogen was detected initially based on microscopy, followed by the molecular confirmation and phylogenetic analysis of the pathogen from bovines from south Punjab, Pakistan. The hematological parameters were also assessed in Ehrlichia positive and negative animals. The information of different disease determinants was analyzed by a logistic regression model on SPSS.

RESULTS

The study has reported an 11.98% (23/192) prevalence of Ehrlichiosis from bovines. The prevalence was slightly more in cattle (13.5%) as compared to the buffaloes (10.4%). The previous tick's history and tick control methods were proved to be the key factors with the occurrence of the disease. The isolates from Pakistan Ehrlichia spp. Pakistan/31, 36, and 8 clustered with the isolates from the USA, Nicaraguan, France, South Africa, and Uganda. Platelet count, hemoglobin level, and hematocrit were found significantly decreased in Ehrlichia affected animals when compared to the healthy bovines.

CONCLUSION

This is the first report of ehrlichiosis from bovines in Pakistan and will provide the roadmap for future research.

Prevalence, epidemiology, seasonality, and phylogeny of Anaplasma marginale in blood samples of goats collected from Punjab, Pakistan

PURPOSE

In Pakistan, a major constrain to goat farming is the tick and tick-borne diseases that results in financial losses to livestock farmers. This study was conducted to report the molecular prevalence of Anaplasma (A.) marginale in goat blood samples collected during four seasons from Khanewal district in Punjab (Pakistan).

METHODS AND RESULTS

The mps1 gene of A. marginale was targeted in 900 blood samples that were collected on seasonal basis (n = 225 per season) and 6.6% (61/900) goats were found positive with A. marginale. Anaplasma marginale positive PCR products were sequenced and submitted to the GenBank. Prevalence of A. marginale varied with sampling season (P = 0.002) and it was highest in the summer (11.5%) followed by the autumn (7.6%), spring (5.3%), and winter seasons (2.7%) respectively. Anaplasma marginale prevalence varied significantly between goat breeds during the autumn (p = 0.01) and summer seasons (p = 0.02). Goats more than 2 years old and livestock farms where only goats were kept and dogs were associated with herds were risk factors for ovine anaplasmosis during different seasons. White and red blood cell counts and parameters associated with their counts were affected in A. marginale infected goats while studied serum parameters remained unaffected.

CONCLUSION

PCR is a reliable tool for the detection of A. marginale in goat blood samples. A relatively low prevalence of A. marginale in goats of Khanewal district was observed and the parasite prevalence in goats was higher in the summer (May until September) and autumn (October and November) seasons. Control measures are required to prevent tick-borne diseases in ruminants from Pakistan.

Anaplasma ovis infection in sheep from Iran: molecular prevalence, associated risk factors, and spatial clustering

The aim of this cross-sectional study was to determine the molecular prevalence and associated risk factors in sheep populations of Iran. To this end, between March 2017 and February 2018 jugular vein blood samples were collected from 1842 apparently healthy sheep from 327 herds in nine provinces in four ecological zones of Iran. A specific nested-PCR targeting the msp4 gene of A. ovis was employed. Fourteen variables were subjected to logistic regression analyses (univariate and multivariate) to specify the potential risk factors for infection. Statistically significant variables in univariate analyses (P ≤ 0.20) were assessed by multivariable logistic regression to control the confounding factors. Anaplasma ovis DNA was detected in 51.1% of herds (167/327) and 28.3% of animals (521/1842). Among geographical zones, herd and animal prevalence was highest in the Persian-Gulf zone (P < 0.001), and among provinces, Lorestan (in west) and Khuzestan (in south-west) had the highest prevalence (P < 0.001). Analysis of factors associated with A. ovis infection revealed that distance from other farms (OR = 2.52, P < 0.001), presence of other animal species in the farm (OR = 2.03, P = 0.046), season (OR = 1.40, P = 0.005), breed (OR = 3.762, P < 0.001), and age of sheep (OR = 1.20, P = 0.049) are potential risks in Iran. The spatial scan statistic in SaTScan recognized two high risks clusters for A. ovis infection in central (Semnan province) and the Persian-Gulf (Khuzestan province) zones amongst the study areas (P < 0.001). Sequence and phylogenetic analysis of the msp4 gene confirmed the detection of A. ovis. This research is the largest study focusing on ovine anaplasmosis in Iran and shows that infected sheep are present in all geographic zones, bioclimatic areas, and provinces.

Molecular detection and prevalence of Theileria ovis and Anaplasma marginale in sheep blood samples collected from Layyah district in Punjab, Pakistan

Theileria ovis and Anaplasma marginale are intracellular pathogens affecting a wide range of animals, causing huge economic losses worldwide. The present study reports the molecular evidence of Theileria ovis and Anaplasma marginale in sheep blood samples (N = 218) collected from Layyah district in Punjab (Pakistan), where economy heavily relies on livestock. A 520 base pair fragment specific for 18S ribosomal RNA gene of Theileria ovis was PCR amplified in 23/218 (10.6%) sheep blood samples, while for Anaplasma marginale, a 265 base pair fragment specific for msp1b gene was generated in 15/218 (6.9%) sheep blood samples. Two blood samples were found co-infected (0.9%) with both parasites. Amplified PCR products of both parasites were confirmed by DNA sequencing and submitted to GenBank. Prevalence of both Theileria ovis (p = 0.3) and Anaplasma marginale (p = 0.4) varied non-significantly among the investigated sheep breeds. Tick burden on dogs present with sheep herds was found associated with Theileria ovis infection in sheep (p = 0.05). It was observed that lambs (p = 0.009), sheep in small herds (p = 0.04), and tick burden on dogs present with sheep herds (p = 0.01) were associated with Anaplasma marginale infection in sheep during the present study. In conclusion, we are reporting a higher prevalence of Theileria ovis than Anaplasma marginale in blood samples of sheep collected from Layyah district. Tick-infested dogs were found to be risk factors for the transmission of both pathogens in sheep, and tick control strategies should be extended to dogs associated with sheep herds in this area.

MOLECULAR INVESTIGATION AND PHYLOGENETIC ANALYSIS OF ANAPLASMOSIS IN DOGS

Anaplasmosis is a widespread vector-borne disease affecting dogs, and Anaplasma platys is the major etiological agent of the disease. The study examines anaplasmosis molecular prevalence, related risk factors, and alteration of hematological variables in Anaplasma-affected dogs. A total of 150 blood samples were collected from dogs in the district of Lahore, Pakistan. The samples were screened with PCR targeting the 16S rRNA gene of Anaplasma. Sequencing of samples that were found positive after performing PCR was conducted. A questionnaire was developed to collect epidemiological data on subject dogs, and the information was analyzed with a logistic regression model using SPSS. The current study revealed an 11.34% (17/150) prevalence of anaplasmosis in dogs based on PCR detection. Tick infestation, previous tick history, house hygiene, and tick control status were major risk factors linked with disease occurrence. Red blood cell count, packed cell volume, hemoglobin, and platelet count were decreased significantly (P < 0.05) in Anaplasma-infected dogs. Phylogenetically, the 2 isolates of the current study clustered together, and that cluster was very similar to A. platys isolates from India, Malaysia, and Thailand.

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.

Molecular evidence of Anaplasma infection in naturally affected domestic cats of Pakistan

Feline anaplasmosis is considered as an emerging tick-borne disease of zoonotic potential. The aim of current study was to investigate the molecular prevalence of anaplasmosis, associated risk factors, and alterations in hematological parameters of domestic cats from Lahore, Pakistan. Blood samples of 100 domestic cats from district Lahore were examined microscopically and the extracted genomic DNA from each sample was processed for the amplification of 16 S rRNA gene of Anaplasma. PCR confirmed isolates were purified for sequencing. The data regarding the risk factors was collected in a predesigned questionnaire and statistically analyzed by logistic regression analysis. The study found a molecular prevalence of 13% (13/100) among analyzed blood samples. The nucleotide analysis of Anaplasmataceae species sequences amplified by PCR showed high resemblance (99%) with isolates from Korea, Japan, Malaysia, Philippines, and India. The potential risk factors found to be significantly associated (p < 0.05) with disease dynamics based on the Chi-Square test were tick infestation on studied animals, previous tick history, tick control status, house hygiene, and housing type. A significant (p < 0.05) decrease in the number of platelets, erythrocytes, hemoglobin level, and pack cell volume was observed in cats suffering from anaplasmosis compared to the healthy ones. The current study is the first report of Anaplasma infection in domestic cats of Pakistan. This study will be effectual in designing the control strategies for this disease.