Isolation and molecular identification of Leptospira santarosai and Leptospira interrogans in equines from eastern Mexico

Leptospirosis is an infectious disease with a worldwide distribution, which represents a major challenge in animal production across developing countries, mainly in tropical areas. Horses are particularly susceptible to the disease, presenting manifestations ranging from subclinical to the development of uveitis that compromises the visual health of the animals. In recent years, serological studies have been carried out in equid populations from America, demonstrating high exposure. For this reason, the aim of this study was to demonstrate microbiologically and molecularly the presence of the members of the genus Leptospira in urine samples from equids in an endemic state of leptospirosis in Mexico, and to detect the serological presence of anti-Leptospira antibodies in the sampled animals. For this reason, blood and urine samples were collected from 28 horses and one mule from three localities in the state of Veracruz, Mexico. Urine samples were inoculated in Ellinghausen-McCullough-Johnson-Harris (EMJH) medium, and the recovered isolates were typed using a short Multi Locus Sequence Typing scheme. Amplifications of the expected size were subjected to sequencing, and the recovered sequences were compared with those of reference deposited in GenBank using the BLAST tool. To identify their phylogenetic position, we performed a phylogenetic reconstruction using the maximum likelihood method. Additionally, Microscopic Agglutination test was performed on the serum samples to identify anti-Leptospira antibodies. We recovered 16 urine isolates which tested positive for the presence of Leptospira DNA. The phylogenetic reconstruction and the MLST analysis confirmed the presence of several genotypes of Leptospira interrogans and Leptospira santarosai. An overall serological frequency of 97.1% was detected. Our results represent the first record of the presence of Leptospira through bacteriological isolates in equids from Mexico.

In vitro and in silico studies of the acaricidal and anticholinesterase activities of Randia aculeata seeds against the southern cattle tick Rhipicephalus (Boophilus) microplus

Rhipicephalus (Boophilus) microplus is a leading cause of significant economic losses in the livestock industry, and tick populations have developed multiple forms of resistance to acaricides; therefore, the potential of novel natural bioactive compounds that are effective for targeting ticks must be addressed. The aim of this study was to evaluate the acaricidal and anticholinesterase activities of R. aculeata seeds and to identify naturally occurring compounds that potentially inhibit anticholinesterase through in silico docking. The acaricidal activity of the extract of R. aculeata seeds against larval and adult R. microplus ticks was assessed through immersion tests. Inhibition of anticholinesterase activity was measured spectrophotometrically. Extracts of R. aculeata seeds showed activity against larvae and engorged females of R. microplus, and a reduction in the reproductive index were also observed. Rutin, chlorogenic acid, quercetin, and epicatechin exhibited noteworthy interactions with the active site residues of RmAChE. These findings could significantly contribute to the exploration of novel natural products that can potentially inhibit RmAChE and could be used in the development of new acaricides for tick control.

Effect of an altitudinal gradient on the morphology, molecular identification and distribution of Rhipicephalus linnaei in Veracruz, Mexico

Studies of morphological and genetic variation in vector populations across environmental gradients can help researchers to estimate species' responses to climate change scenarios and the potential risk of disease-causing pathogen expansion, which impacts negatively on human health. In this study, we analysed the effect of altitudinal gradients on the phenotypic response of the hard tick of medical and veterinary importance, Rhipicephalus sanguineus sensu lato (s.l.). Specimens of R. sanguineus s.l. were collected from host animals in one of Mexico's regions with high climatic heterogeneity (Veracruz), and geometric morphometric theory was employed to assess the response of three morphological characters to the altitudinal gradient. Additionally, genetic similarity data were provided, and ecological niche models were used to project the climatic distribution in the region. Our results demonstrate that the shape and size of ticks respond to altitude. Molecular identification indicate that all analysed samples correspond to the tropical lineage recently named Rhipicephalus linnaei. According to ecological niche models, the mean annual temperature contributes significantly to the spatial distribution of this tick species, with areas of higher suitability in the mountainous region. These changes in morphological structure and the presence of ticks at higher altitudinal gradients suggest that R. linnaei has a high potential for adaptation. Due to the variability of ecosystems in the state of Veracruz, our results could be valuable in assessing the response of this tick in a changing environment, aiding in predicting future scenarios in the distribution and abundance of this species.

METARHIZIUM ANISOPLIAE SENSU LATO NATIVE TO LIVESTOCK SOILS CAUSES HIGH MORTALITY ON RHIPICEPHALUS MICROPLUS LARVAE, ADULTS AND AFFECTS THEIR REPRODUCTION

The acaricidal effect of 14 strains of Metarhizium anisopliae sensu lato isolated from soil of livestock farms in the Mexican tropics was evaluated against larvae and engorged females, and during the laying and hatching of eggs of Rhipicephalus microplus (Ixodida: Ixodidae). For each fungal strain, the larvae mortality percentage was evaluated through a larval immersion test, while the reproductive efficiency indices in engorged females were measured using adult immersion tests at a dose of 1 × 108 conidia/ml. All strains of M. anisopliae (s.l.) proved to be highly effective against R. microplus larvae (66-100%) and engorged females (100%). The strains also showed a good effect in inhibiting egg laying (16.45-56.38%) and a moderate effect in decreasing egg hatching (5.24-32.68%). Two strains demonstrated to be effective against all development phases of R. microplus in an integrated manner.

Detection of Bartonella bovis DNA in blood samples from a veterinarian in Mexico

The genus Bartonella encompasses 38 validated species of Gram-negative, facultative intracellular bacteria that colonize the endothelial cells and erythrocytes of a wide spectrum of mammals. To date, 12 Bartonella species have been recorded infecting humans, causing diseases of long historical characterization, such as cat scratch fever and trench fever, and emerging bartonellosis that mainly affect animal health professionals. For this reason, this study aimed to report a documented case of Bartonella bovis infecting a veterinarian from Mexico by the amplification, sequencing and phylogenetic reconstruction of the citrate synthase (gltA) and the RNA polymerase beta-subunit (rpoB) genes, and to report the natural course of this infection. To our knowledge, this work is the first to report the transmission of B. bovis via needlestick transmission to animal health workers in Latin America.

Worldwide comparison between the potential distribution of Rhipicephalus microplus (Acari: Ixodidae) under climate change scenarios

The cattle tick Rhipicephalus microplus (Acari: Ixodidae) has demonstrated its ability to increase its distribution raising spatially its importance as a vector for zoonotic hemotropic pathogens. In this study, a global ecological niche model of R. microplus was built in different scenarios using Representative Concentration Pathway (RCP), Socio-Economic Pathway (SSP), and a climatic dataset to determine where the species could establish itself and thus affect the variability in the presentation of the hemotropic diseases they transmit. America, Africa and Oceania showed a higher probability for the presence of R. microplus in contrast to some countries in Europe and Asia in the ecological niche for the current period (1970-2000), but with the climate change, there was an increase in the ratio between the geographic range preserved between the RCP and SSP scenarios obtaining the greatest gain in the interplay of RCP4.5-SSP245. Our results allow to determine future changes in the distribution of the cattle tick according to the increase in environmental temperature and socio-economic development influenced by human development activities and trends; this work explores the possibility of designing integral maps between the vector and specific diseases.

Molecular detection of Theileria cervi in equids from México

Equine piroplasmosis is a parasitic illness caused by various protozoa of the Babesia and Theileria genera, which parasitize within red blood cells. The transmission of these pathogens occurs through certain genus of ticks, including Amblyomma, Haemaphysalis, Hyalomma, and Rhipicephalus. In recent times, an increase in the identification of new Theileria species and genotypes has been observed. This is further complicated by the presence of mixed Theileria infections in both mammals and tick vectors, particularly in regions where wildlife and livestock share habitats and vectors. Therefore, the objective of this study is to document the occurrence of Theileria cervi in a non-typical host. A total of 88 horses (Equus caballus) and 10 donkeys (Equus asinus) were sampled in three municipalities in Veracruz, Mexico. Molecular techniques were employed to identify Babesia/Theileria through the amplification of a segment of the 18S-rDNA and hsp70 genes. The phylogenetic reconstruction grouped the obtained sequences into a monophyletic cluster alongside sequences of T. cervi. This work represents the first documented occurrence of T. cervi in equids. These findings have significant implications from an epidemiological point of view. In addition, further studies are needed to determine the distribution and pathogenicity of this species for domestic animals and to develop effective control strategies.

Efficacy of hydroethanolic extract of Randia aculeata seed against the southern cattle tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) on naturally infested cattle under field conditions

The cattle tick Rhipicephalus (Boophilus) microplus is a major problem of concern for cattle industry in tropical and subtropical areas. Control of cattle tick is based mainly on the use of chemical acaricides, which has contributed to the emerging problem of selection of resistant tick lineages. Plants have been used as an alternative to conventional acaricidal drugs. On the other hand, the acaricidal activity of hydroethanolic extract of Randia aculeata seed (EHRA) has been demonstrated against R. microplus under laboratory conditions. However, the utility of EHRA seed as a potential acaricidal needs to be determined under field conditions. For this reason, the aim of this study was to evaluate the efficacy of the EHRA against R. microplus sprayed on naturally infested calves, determine the effect of the EHRA seed on acetylcholinesterase activity in R. microplus larval and identify the chemical composition of EHRA. Forty-five male calves were divided in three groups and treated with: G1 water; G2 EHRA 20% w/v and G3 coumaphos 0.2% v/v. Acetylcholinesterase (AChE) activity in R. microplus larvae was determined by a colorimetric assay. The chemical composition of EHRA was accessed through HPLC/MS. Significantly fewer ticks were observed after 24 h on the treated group compared to control group. EHRA significantly inhibited in vitro AChE activity in R. microplus at all tested concentrations. Chlorogenic acid, vanillinic acid, p-coumaric acid, caffeic acid. rutin, quercetin, (-)-epicatechin, 4-hydroxybenzoic acid, quercetin, vanillin, 2,4-dimethoxy-6-methylbenzoic acid, scopoletin and ferulic acid were identified in the extract. The results provided new data for the elucidation of the mechanisms of EHRA acaricide action and to further evaluate the use as a new alternative control agent against R. microplus under in vivo conditions.

Serological and Molecular evidence of pathogenic Leptospira species in cattle from slaughterhouses in Veracruz State, Mexico

Cattle raising is the most important livestock activity in Mexico, highlighting the fact that the Country is eight place worldwide in the production of bovine meat. However, cattle can be affected by leptospirosis (a bacterial disease caused by 17 species of spirochetes of the genus Leptospira), which cause reproductive problems that translate into great economic losses. Additionally, these zoonotic agents can cause a rapidly evolving febrile condition in humans, which can be solved after the first week of symptoms or could progress to develop a severe late-phase manifestations. Despite the great impact of these agents on the economy and Public Health, epidemiological surveillance against the infectious disease that cause is not present in municipal slaughterhouses (MS). Therefore, the aim of this study was to identify, using serological and molecular methods, the circulating Leptospira species in three MS in Veracruz State. The frequency of anti-Leptospira antibodies was 67.5%. Additionally, five sequences were recovered that were 99% similar to L. interrogans. This work represents the first national effort for the evaluation of MS as sentinel units, that allow establishing the diversity of species of the genus Leptospira that circulate in cattle and establishing intervention measures for workers risk mitigation, who come into contact with the fluids and organs of infected animals.

Molecular detection of Coxiella-like endosymbionts and absence of Coxiella burnetii in Amblyomma mixtum from Veracruz, Mexico

Ticks are obligate ectoparasites associated with a wide range of vertebrate hosts, including domestic animals. Moreover, ticks are capable of transmitting many pathogens such as Coxiella. To date, Coxiella burnetii, the etiological agent of coxiellosis or Q fever, is the only valid species of the genera. Nevertheless, a wide range of agents denominated Coxiella-like have been detected in recent studies, mainly associated with ticks. The pathogenicity of these Coxiella-like agents is controversial as some of them can infect both birds and humans. In Mexico, knowledge about Q fever is scarce and limited to historical serological records, and there is an overall lack of molecular proof of any agent of the genus Coxiella circulating in the country. Therefore, the aim of this study was to detect the presence of Coxiella in ticks associated with cattle in all 10 regions of Veracruz, Mexico. To accomplish this objective, first, we identified ticks collected from cattle and horses in Veracruz. Then, for Coxiella detection, DNA extraction from ticks and PCR amplification of the 16S-rDNA of Coxiella was performed. Finally, we performed a phylogenetic reconstruction to determine the Coxiella lineages detected. From the 10 regions sampled we collected 888 ticks grouped in 180 pools, and only five Amblyomma mixtum from the locality of Castán, and one from Los Angeles from Tuxpan were found positive, which represents a frequency of 20% for each locality. This study represents the first attempt at molecular detection of Coxiella in ticks associated with cattle in the state of Veracruz, the major livestock producer in the country. The findings of the present study are relevant as they establish a precedent regarding the circulation of Coxiella-like agents, as well as the absence in three municipalities of the state of Veracruz of C. burnetii, an abortive agent of livestock importance.

Prevalence and risk factors of coccidiosis in calves from Veracruz, México

The objectives of the present study were: (1) to determine the prevalence of Eimeria spp. sporulated oocysts in calves from 26 Municipalities in the Central Zone of the State of Veracruz, Mexico, (2) to identify the Eimeria spp. infecting calves, and (3) to identify the risk factors associated with the presence of Eimeria spp. in tropical cattle. A total of 930 individual fecal samples were analyzed by using the McMaster technique; then, oocysts were maintained in 2.5% potassium dichromate to allow sporulation. The general prevalence of calves with Eimeria spp. oocysts was 39.7% (370/930). Of a total of 10 identified species, Eimeria canadensis was the most observed, followed by Eimeria bovis and Eimeria zuernii. The statistical analysis showed an association between the age of the calves (5 to 9 months), the presence of other animals, the physiographic regions and the restricted type of husbandry with the presence of Eimeria spp. in calves (P<0.05). Protective risk factors, such as: routine coprological analysis was also associated with a decrease in infection. These data demonstrate the presence of coccidia in cattle from the State of Veracruz, additionally to the necessary measures that must be taken to control this parasitosis.

First report of Babesia bigemina in Lama glama in a zoological garden of Veracruz, Mexico

Zoological gardens represent specialised centres for the preservation of biological inventories and genetic diversity, allowing the recognition of multiple species in critical conservation categories. However, the close coexistence of multiple species of vertebrates that may be associated with various species of ectoparasites may be the cause of the transmission of multiple infectious agents, among which tick-borne pathogens stand out. In these areas, several animal species usually live in a small space and proximity to other wildlife, visitors and keepers. In Mexico, little is known about the disease agents transmitted by arthropods in zoological gardens. For this reason, the aim of this study was to identify the presence of Babesia/Theileria in animals maintained in captivity. As a part of a project identifying vector-borne pathogens in wildlife, 24 animals were sampled in the Miguel Angel de Quevedo zoo. Molecular identification of Babesia/Theileria was realised through amplification of a fragment of the mitochondrial cytB gene and the ribosomal 18S-rDNA. Two neotropical camelids (Lama glama) tested positive (2/3 = 66.6%) to Babesia bigemina. Our results represent the first record of B. bigemina in animals in captivity in a zoological garden in Mexico and the first finding of this haemoparasite in neotropical camelids in Mexico.

Spatial epidemiology of Leptospira sp. exposure in bovines from Veracruz, México

Bovine leptospirosis is a bacterial disease that affects cattle herds, causing economic losses due to reproductive problems which require expensive treatments. The main source of transmission for cattle is still uncertain, but rodents and bats can play an important role in the transmission cycle by being maintenance hosts for the pathogenic species of the bacterium and spreading it through urine. In this study, we characterize possible risk areas for bovine leptospirosis exposure in the state of Veracruz, Mexico, based on the geographical distribution of flying (bats) and terrestrial (rodents and opossums) wild hosts of Leptospira sp. reported in Mexico, in addition to climate, geography, soil characteristics, land use and human activities (environmental variables). We used a generalized linear regression model to understand the association between the frequency of anti-Leptospira sp. antibodies (a proxy of exposure) in cattle herds exposed to Leptospira, the favourability of wild hosts of Leptospira as well as the environmental variables. The parameterized model explained 12.3% of the variance. The frequency of anti-Leptospira sp. antibodies exposure in cattle herds was associated with elevation, geographic longitude, pH of the soil surface and environmental favourability for the presence of rodents, opossums and bats. The variation in exposure was mainly explained by a longitudinal gradient (6.4% of the variance) and the favourability-based indices for wild hosts (9.6% of the variance). Describing the possible risks for exposure to Leptospira in an important and neglected livestock geographical region, we provide valuable information for the selection of areas for diagnosis and prevention of this relevant disease.

An atypical case of Babesia bigemina parasitising a dog from a rural area of eastern Mexico

Abstract A dog that shared habitat with domestic animals in a cattle farm and that was exposed to wildlife was taken to a private practitioner for clinical examination. The analyses conducted on the patient revealed the presence of Babesia bigemina by a molecular test. Clinical signs such as lethargy, anorexia and hyperthermia > 39 °C, pale mucous membranes and blood urine were observed in the patient. The animal was treated with imidocarb dipropionate (two doses each 0.5 ml/10 kg b.w. at an interval of 14 days). On treatment day 7, the clinical signs were mostly reduced. On day 30, PCR was carried out to assess the efficacy of the treatment, with a negative result. This case represents the first report of babesiosis due to B. bigemina in a dog living on a cattle farm in Mexico. It indicates the lower host specify of these pathogens and that dogs can play a role as sentinels of vector-borne parasites in livestock animals.

Serosurveillance and risk factors for Neospora caninum infection in water buffaloes (B. bubalis) from central and southern Mexico

The water buffalo (B. bubalis) is an alternative to cattle ranching in several regions of southern Mexico. Here we report seroprevalence and risk factors associated with the protozoan parasite, Neospora caninum, in water buffaloes in six buffalo production units, in municipalities from central and southern Veracruz, Mexico. Antibodies to N. caninum were assessed in serum samples of 543 buffaloes by a commercial ELISA-kit, and 44.8% (243/543; 95% CI 40.5-49.0) were seropositive. Questionnaires were used to collect epidemiological data and to identify risk factors associated with N. caninum infection. Data analysis indicated that older buffaloes (≥7 year) exhibited the highest seroprevalence for neosporosis 62.3% (38/61; 95% CI 49.7-73.4) (P ≤ 0.05). Buffaloes that were in close contact with cattle had higher seroprevalence 47.6% (168/353; 95% CI 42.3-52.9) (P < 0.01) than those that were not in contact 36.8% (70/190; 95% CI 30.0-44.1). Our findings provide important information to implement preventive measures in the buffalo farms.

Acaricidal activity of the hexanic and hydroethanolic extracts of three medicinal plants against southern cattle tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)

The southern cattle tick Rhipicephalus microplus is a major problem for the cattle industry in tropical and subtropical areas worldwide. Chemical products are commonly applied to control it; however, their indiscriminate use has resulted in the appearance of resistant lineages. In the last decades, plants have been used as an alternative to conventional acaricidal drugs, as several plant compounds repel activity, decrease the reproductive potential and reduce the survival rate of ticks. For this reason, the in vitro efficacy of hexanic and hydroalcoholic extracts of Randia aculeata, Moringa oleifera and Carica papaya were evaluated against the larvae and engorged females of R. microplus. Larval packet tests and adult immersion tests were performed with seven concentrations of each of the extracts. The extracts obtained with hydroethanolic solution (polar solvent) exhibited a higher acaricidal activity than extracts prepared with n-hexane (non-polar solvent). Hydroethanolic extracts of R. aculeata seed and shell showed the highest larvicidal activity against R. microplus (100 and 91% mortality, respectively) at a concentration of 100 mg/mL. Randia aculeata (seed and shell), M. oleifera and C. papaya treatments at the same concentration (100 mg/mL) also resulted in adult mortality of 85, 75, 66 and 55%, respectively. The adult immersion test showed that hydroethanolic extracts derived from R. aculeata seed significantly reduced the index of egg laying and increased the percentage inhibition of oviposition of female ticks at a concentration of 100 mg/mL. These results indicate that the tested extracts exhibit acaricidal activity and could be considered as potential agents for the development of alternative natural acaricides against R. microplus.

No molecular evidence of SARS-CoV-2 infection in companion animals from Veracruz, Mexico

Active epidemiological surveillance of infectious agents represents a fundamental tool for understanding the transmission dynamics of pathogens and establishing public policies that can reduce or limit their expansion. Epidemiological surveillance of emerging agents, such as the recently recognized severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of COVID-19, is essential to establish the risk of transmission between species. Recent studies reveal that companion animals are organisms susceptible to being infected by this pathogen due to the close contact they have with their owners. For this reason, the aim of the present work was to detect the presence of SARS-CoV-2 in dogs and cats in the state of Veracruz, Mexico, where there is active transmission of this microorganism in human populations. Oral and nasopharyngeal swab samples were collected from dogs and cats with a history of exposure to patients with COVID-19. Total RNA was extracted and detection of viral genes N1 and N2 was performed by reverse transcription polymerase chain reaction (RT-qPCR). All 130 samples of companion animals tested by RT-qPCR for SARS-CoV-2 were negative at the time they were collected. This study represents the second active surveillance of SARS-CoV-2 in populations of domestic dogs and cats in Latin America and the first approach in Mexico. Given that coronaviruses have shown a high capacity to be transmitted between species, it is imperative to establish measures to prevent this agent from entering and establishing in populations of companion animals.

Inferring the Potential Distribution of an Emerging Rickettsiosis in America: The Case of Rickettsia parkeri

Tick-borne rickettsioses represent a severe public health problem that has increased in recent decades by several activities that place human populations in contact with a wide range of vectors. In particular, Rickettsia parkeri, an eschar-associated spotted fever agent, represents an emerging pathogen that has been gradually identified throughout America. In the present work, we compiled an occurrence database of these bacteria, as well as its vectors, in order to identify the potential distribution of these bacteria and to detect the risk areas where this emerging pathogen may be circulating. The results show the at-risk areas to be broad regions in Central America, on the coast of Venezuela, Colombia, Ecuador, Peru, and Chile, part of Brazil and Argentina, and the greater part of Bolivia, Paraguay, and Uruguay. Particularly, in Mexico, conditions exist for widespread dissemination. Our results must be considered for the establishment of active acarological surveillance in previously unsampled areas, as well as the establishment of prevention measures for vulnerable populations and risk groups participating in outdoor activities that can place them in contact with this pathogen.

Morphometrics of Amblyomma mixtum in the State of Veracruz, Mexico

The tick Amblyomma mixtum is an ectoparasite of veterinary and public health importance because of its role as a vector of zoonotic pathogens. However, little is known about A. mixtum intraspecific variability and if morphological differentiation exists between populations across its geographic range. This study aimed to determine by electron microscopy the morphological variability of A. mixtum populations in the state of Veracruz, which has a large livestock population among states in Mexico. Forty male and 40 female A. mixtum collected from the 10 natural regions of Veracruz state were analyzed microscopically to accomplish main component analysis for each sex. Clusters were calculated with the out-tree method and a dendrogram produced to group the specimens according to their morphometric characteristics. Using 10 main components, 77% of the morphological variation of the ticks was explained. This is a reflection of scarce intraspecific variation between females. The dendogram for females grouped six clusters of specimens with similar characteristics. Morphometric variability in males was described using eight main components. Limited intraspecific variation was also observed between males. In males, the dendogram yielded six groups with similar morphometric characteristics. Morphometric analyses confirmed that the only species from the Amblyomma cajennense complex that are parasites to livestock in Veracruz state is A. mixtum. The eryxenous nature of A. mixtum combined with the frequent movement of livestock hosts may contribute to the apparent homogeneous phenotype of this tick species in Mexico.

Molecular detection of Theileria equi in horses from Veracruz, Mexico

Equine piroplasmosis is a tropical parasitic disease caused by several intraerythrocytic members of the genera Babesia and Theileria. These pathogens are transmitted by multiple tick species and are considered as important exotic microorganisms in several countries. Equine piroplasmosis causes significant economic losses due to abortions, decreased activity and even death of equines, making surveillance of these infectious disease essential. In the northern and eastern parts of Mexico, few molecular and serological reports have been made on the presence and exposure of horse to these agents. For this reason, the aim of the current work was to perform a molecular detection study of Babesia and Theileria in equines from the state of Veracruz, Mexico. A total of 100 whole blood samples were tested. Chelex-100 resin was used for DNA extraction and a fragment of 459 bp of the 18S rRNA gene of members of the genera Babesia/Theileria were identified. Of the 100 samples analysed, 18 tested positive for Babesia/Theileria, resulting in a prevalence of 18 %. Identity analyses and phylogenetic reconstruction revealed that all samples were infected with Theileria equi. This work represents the first molecular record of Babesia/Theileria in equines from the state of Veracruz, Mexico, and demonstrates the endemicity of T. equi in this region of the country.

The genus Rickettsia in Mexico: Current knowledge and perspectives

The genus Rickettsia encompasses 35 valid species of intracellular, coccobacilli bacteria that can infect several eukaryotic taxa, causing multiple emerging and re-emerging diseases worldwide. This work aimed to gather and summarise the current knowledge about the genus Rickettsia in Mexico, updating the taxonomy of the bacteria and their hosts by including all the records available until 2020, to elucidate host-parasite relationships and determine the geographical distribution of each Rickettsia species present in the country. Until now, 14 species of Rickettsia belonging to four groups have been recorded in Mexico. These species have been associated with 26 arthropod species (14 hard ticks, three soft ticks, two sucking lice, and seven fleas) and 17 mammal species distributed over 30 states in Mexico. This work highlights the high biological inventory of rickettsias for Mexico and reinforces the need to approach the study of this group from a One Health perspective.

Integrative taxonomic description of the chewing louse Tricholipeurus lipeuroides infesting Odocoileus virginianus veraecrucis white-tailed deer in Veracruz, Mexico

Chewing lice (Phthiraptera: Amblycera, Ischnocera) represent a component of the ectoparasite fauna associated with large sized mammals as deers. However, the diversity of chewing louse species infesting deer remains to be fully characterized in the Neotropics. Little is known about the chewing lice infesting the extant fourteen subspecies of white-tailed deer (Odocoileus virginianus) in Mexico. Known to infest white-tailed deer (WTD) in Canada and the United States (U.S.), Tricholipeurus lipeuroides is a chewing louse species that was originally described in the nineteenth century infesting O. v. mexicanus in Mexico. For the first time, infestation of O. v. veraecrucis, a Neotropical WTD subspecies in Mexico, with T. lipeuroides is reported herein. An integrative taxonomic approach was taken by combining morphological and molecular analyses to describe the T. lipeuroides infestion of O. v. veraecrucis. Ecological parameters of the T. lipeuroides infestations were also calculated. The prevalence was 91.7% of the 56 O. v. veraecrucis (29 females and 27 males) inspected while under chemical restraint that were sampled at 3 sites in the central region of Veracruz state in Mexico. The amplification and sequencing of previously reported T. lipeuroides Cytochrome Oxidase Subunit I gene confirmed the identity of all the chewing louse life stages. These results are discussed in the context of comparative analyses on the emergence of novel chewing lice-deer associations.

Molecular detection of Rickettsia species in ticks collected in the Mexico-USA transboundary region

Zoonotic tick-borne diseases, including those caused by Rickettsia species, continue to have serious consequences for public health worldwide. One such disease that has emerged as a major problem in several countries of the American continent is the Rocky Mountain Spotted Fever (RMSF) caused by the bacterium Rickettsia rickettsii. Several tick species are capable of transmitting R. rickettsia, including Amblyomma cajennense, A. aureolatum, A. imitator, Rhipicephalus sanguineus, Dermacentor andersoni, D. variabilis and possibly A. americanum. Despite previous reports in Mexico linking new outbreaks of RMSF to the presence of these tick species, no robust measures have tackled transmission. In the present study, we amplified R. rickettsii from 109 test DNA samples extracted from ticks collected from several animals and humans of Tamaulipas, Mexico, between November 2015 and December 2017. Our analysis revealed the presence of R. rickettsii in six samples and these findings contribute to a spatial distribution map that is intended to minimize the risk of transmission to humans.

Endoparásitos de Odocoileus virginianus y Mazama temama bajo cautiverio en Veracruz, México

El estudio de la parasitología de animales silvestres de importancia económica en cautiverio es relevante, ya que la parasitosis se traduce en pérdidas por disminución de productividad, aumento de gastos veterinarios, infecciones secundarias y pérdida de ejemplares. El objetivo de este trabajo fue determinar la prevalencia y abundancia de la diversidad de endoparásitos presentes en Odocoileus virginianus y Mazama temama en cautiverio. Durante la temporada de lluvias y secas, se recolectaron 60 muestras fecales de seis ejemplares de O. virginianus y cuatro de M. temama de diferente edad y sexo; se usó la técnica de flotación con solución saturada de azúcar, para recolectar e identificar los parásitos mediante comparación anatómica. Se identificaron siete géneros de parásitos: Ascaris sp., Eimeria sp., Estrongilido sp., Strongyloides sp., Parascaris sp., Paragonimus sp., y Taenia sp., siendo los dos primeros con mayor abundancia en ambos cérvidos. La prueba de X2 determinó que la presencia de endoparásitos está asociada al sexo y a la especie de venado: machos y hembras de cada especie de venado, presentaron distinta prevalencia parasitaria. Parascaris sp. y Paragonimus sp., fueron parásitos que se encontraron solamente en O. virginianus. No se encontraron diferencias significativas (P>0.05) entre la abundancia de parásitos entre las épocas de lluvias y secas; el género Ascaris fue significativamente más abundante con respecto a otros parásitos (P<0.05). Esta información sirve para el control y prevención de parásitos de ungulados en cautiverio de importancia económica y para su conservación.

Rickettsia species in ticks that parasitize amphibians and reptiles: Novel report from Mexico and review of the worldwide record

Ticks are obligate haematophagous ectoparasites that are associated with a wide range of vertebrate hosts, among them also reptiles and amphibians. They have dynamic ecological interactions with multiple microorganisms, ranging from endosymbionts to pathogens, such as the members of the genus Rickettsia. The aim of this work was to detect Rickettsia in ticks from amphibians and reptiles from southern Mexico by the amplification, sequencing and phylogenetic reconstruction of the gltA and ompA genes, and also to compile all the published records worldwide of Rickettsia associated with ticks attached to reptiles and amphibians, in order to elucidate the host-parasite relationships, and to identify the geographical distribution of each bacterial species. We record for the first time the presence of Rickettsia sp. strain Colombianensi and Rickettsia amblyommatis in ticks from several reptiles and amphibians collected in three new localities from the states of Guerrero and Veracruz, Mexico. Additionally, we here report 23 Rickettsia taxa associated with 18 tick species attached to 42 host taxa of amphibians and reptiles in 36 countries. Our findings increase the inventory of rickettsia reported in Mexico and summarizes the knowledge of these bacteria associated with ticks of this particular group of vertebrate host worldwide.

Prevalence and risk factors of Neospora caninum infection in ovine flocks of central-western Mexico

This study, carried out in 13 sheep flocks of central-western Mexico, aimed to identify the prevalence of anti-N. caninum antibodies, to develop a risk analysis of the infection and to estimate the prevalence of parasite DNA in blood. A total of 368 serum and blood samples were subjected to ELISA and PCR tests, respectively, and the association between the prevalence of antibodies and some management factors was estimated. The overall prevalence of anti-N. caninum antibodies was 13.5% [50/368; 95% confidence interval (CI) 10-17], ranging from 2.7 to 90% per flock, and 92% of the farms had seropositive animals. In ewes the prevalence was 14% (48/348, 95% CI 10-17) and in rams 10% (2/20; 95% CI 1- 33). The mean prevalence of Neospora DNA in blood was 27% (99/368, 95% CI 22-31), implying a range between 16 and 82%. In rams, the prevalence was 5% (1/20 95% CI 2-26), while in ewes it was 28% (98/348, 95% CI 23-33). The agreement between the tests was k = 0.19. The presence of other domestic animal species in the farms [odds ratio (OR) 4.4] and the consumption of placental debris, fetuses and stillborn lambs by dogs living in the farms (OR 5.8) were demonstrated to be risk factors.

Occurrence of Amblyomma mixtum on the water buffalo (Bubalus bubalis) in Mexico

The water buffalo (Bubalus bubalis) is an Asian species of bovine that was introduced in Mexico in 1992 as an alternative for milk and meat production. To date, no surveys have been conducted to identify ticks acquired by water buffaloes since their arrival in the country. Here we report, for the first time, the presence of Amblyomma mixtum, a neotropical tick in the Amblyomma cajennense complex, found on water buffaloes from Mexico and discuss its possible implications in veterinary public health for the region.

Seroepidemiology of Leptospira Infection in Backyard Pigs in Durango State, Mexico

Purpose

This study aimed to determine the seroprevalence and correlates of Leptospira IgG antibodies in backyard pigs in the northern Mexican state of Durango. We performed a cross-sectional study of 305 backyard pigs. Anti-Leptospira IgG antibodies were detected using microscopic agglutination assay (MAT) with a panel of 12 Leptospira antigens.

Results

Overall, antibodies against Leptospira (any of the 12 Leptospira serovars examined) were found in 186 (61.0%) of the 305 pigs studied. Seropositive pigs were found on 80 (70.2%) of the 114 properties surveyed. The predominant serovar was Leptospira interrogans Pomona (n = 55); followed by Leptospira noguchii Lousiana and Leptospira santarosai Tarassovi (n = 53 each); L. interrogans Bataviae (n = 47); Leptospira biflexa Semaranga and L. interrogans Hebdomadis (n = 36 each); L. interrogans Pyrogenes (n = 30); L. interrogans Djasiman (n = 20); Leptospira borgpetersenii Ballum (n = 11); L. noguchii Panama and L. interrogans Canicola (n = 5 each); and L. borgpetersenii Mini (n = 2). Logistic regression showed that seropositivity was associated with low (<1000 m above sea level) altitude (odds ratio [OR] = 3.24; 95% confidence interval [CI]: 2.01–5.20; P < 0.001).

Conclusions

This is the first report of Leptospira exposure in backyard pigs in Mexico and of an association between Leptospira exposure in pigs and altitude. Backyard pigs represent a high-risk group for Leptospira exposure.

Apparently high Leptospira antibody seropositivity in donkeys for slaughter in three municipalities in Durango, Mexico

We determined the seropositive percentage and the determinants of Leptospira exposure in domestic donkeys presented for slaughter in the State of Durango, Mexico. We examined 194 donkeys in 4 gathering premises. Sera of donkeys were analyzed for anti- Leptospira IgG antibodies using a microscopic agglutination assay with a panel of 7 Leptospira antigens. The association between Leptospira seropositivity and general characteristics of donkeys was assessed by bivariate and multivariate analyses. Antibodies against Leptospira (for at least 1 of the 7 Leptospira serovars examined) were found in 151 of 194 (77.8%) donkeys. Seropositive donkeys were found in all regions, municipalities, and premises examined. The predominant serovar was L. interrogans Icterohaemorrhagiae ( n = 117; 60.3%), followed by L. interrogans Sejroe ( n = 96; 49.5%), L. interrogans Canicola ( n = 10; 5.2%), L. kirschneri Grippotyphosa ( n = 6; 3.1%), L. borgpetersenii Ballum ( n = 5; 2.6 %), L. biflexa Semaranga ( n = 3; 1.5%), and L. noguchii Panama ( n = 2; 1%). Leptospira seropositivity was associated with gathering premises (OR = 2.64; 95% CI: 1.27-5.46; p = 0.009) and municipalities (OR = 0.11; 95% CI: 0.01-0.78; p = 0.02). Our results demonstrate an apparently high seropositive percentage of Leptospira infection in the donkeys studied in Mexico.

Genetic structure analysis of Amblyomma mixtum populations in Veracruz State, Mexico

Amblyomma mixtum Koch, 1844 parasitizes livestock, humans, and wildlife in Mexico. However, information on population genetics for this tick species in the country is missing. Tick samples were collected from livestock in ten regions across the state of Veracruz (22°28'N, 17°09'S, 93°36'E, 98°39'W) to analyze the genetic structure of   A. mixtum populations. Ticks were morphologically identified using taxonomic keys. In order to test the intra-specific variability of A. mixtum fragments of the mitochondrial gene 16S-rRNA and cytochrome oxidase subunit 1 (COI) were amplified. Ninety-six sequences were amplified from the 50 specimens' analyzed (96% amplification success). Eleven haplotypes were detected in 16S-rRNA gene and 10 more for COI. Neutrality tests showed negative results in most of the locations analyzed, which is indicative of an excess of recently derived haplotypes. However, these results were not statistically significant. Minimal union network analysis revealed that there is no separation of populations by geography, and that there is an overlap of several haplotypes among diverse populations. Significant genetic differentiation was not detected in the A. mixtum populations sampled in the state of Veracruz, Mexico, this may be due to the frequent movement of livestock hosts. This is the first report on the genetic structure of A. mixtum populations in Mexico.

Seroepidemiology of Bovine Herpes Virus-1 Infection in Water Buffaloes from the state of Veracruz, Mexico

Water buffaloes (Bubalus bubalis) were introduced to Mexico at the end of the last century. In Mexico, buffaloes are commonly pastured together with cattle; however few studies have been done on buffalo herd health in Mexico. We hypothesized that a better knowledge of the epidemiology of infections shared between cattle and buffaloes may improve herd profitability and promote buffalo production in areas unsuitable to cattle farming. This study aimed to determine the prevalence of antibodies against bovine herpes virus - 1 (BoHV1) in water buffaloes raised on six farms from the state of Veracruz, Mexico. Of 368 buffaloes sampled, 217 (59%) were seropositive for BoHV-1. Age was identified as a risk factor for BoHV-1 infection with buffaloes older than 5 years being the most likely to be infected. Animals more than 7 years old had the highest prevalence (86.0%). Females and males had similar seroprevalence rates. Females with history of abortion had higher prevalence of antiBoHV-1 antibodies than those with no record of abortion. Buffaloes and cattle were raised together in only one of the six farms under study. Interaction with cattle was not a risk factor for BoHV-1 seropositivity. This study showed that BoHV-1 is prevalent among buffalo herds in the state of Veracruz, Mexico. Buffaloes appear to play an important role in the epidemiology of BoHV-1 infection in parts of Mexico when there is no apparent risk of interaction with cattle. Animal health programs established to mitigate the burden caused by BoHV-1 must take into consideration buffaloes when this bovid species is part of the agroecosystem shared with cattle.

Detection of pathogenic Leptospira species associated with phyllostomid bats (Mammalia: Chiroptera) from Veracruz, Mexico

The genus Leptospira encompass 22 species of spirochaetes, with ten pathogenic species that have been recorded in more than 160 mammals worldwide. In the last two decades, the numbers of records of these agents associated with bats have increased exponentially, particularly in America. Although order Chiroptera represents the second most diverse order of mammals in Mexico, and leptospirosis represents a human and veterinary problem in the country, few studies have been conducted to identify potential wildlife reservoirs. The aim of this study was to detect the presence and diversity of Leptospira sp. in communities of bats in an endemic state of leptospirosis in Mexico. During January to September 2016, 81 bats of ten species from three localities of Veracruz, Mexico, were collected with mist nets. Kidney samples were obtained from all specimens. For the detection of Leptospira sp., we amplified several genes using specific primers. Amplicons of the expected size were submitted to sequencing, and sequences recovered were compared with those of reference deposited in GenBank using the BLAST tool. To identify their phylogenetic position, we realized a reconstruction using maximum-likelihood (ML) method. Twenty-five samples from three bat species (Artibeus lituratus, Choeroniscus godmani and Desmodus rotundus) showed the presence of Leptospira DNA. Sequences recovered were close to Leptospira noguchii, Leptospira weilii and Leptospira interrogans. Our results include the first record of Leptospira in bats from Mexico and exhibit a high diversity of these pathogens circulating in the state. Due to the finding of a large number of positive wild animals, it is necessary to implement a surveillance system in populations of the positive bats as well as in related species, in order to understand their role as carriers of this bacterial genus.

Seroepidemiology of Infection with Neospora Caninum, Leptospira, and Bovine Herpesvirus Type 1 in Water Buffaloes (Bubalus Bubalis) in Veracruz, Mexico

We aimed to determine the seroprevalence of infection with Neospora caninum, Leptospira, and bovine herpesvirus type 1 and risk factors associated with these infections in water buffaloes in Veracruz State, Mexico. Through a cross-sectional study, 144 water buffaloes (Bubalus bubalis) raised in 5 ranches of Veracruz were examined for anti-N. caninum and anti-bovine herpesvirus type 1 antibodies by enzyme immunoassays, and anti-Leptospira interrogans antibodies by microscopic agglutination test.

Of the 144 buffaloes studied, 35 (24.3%) were positive for N. caninum, 50 (34.7%) for Leptospira, and 83 (57.6%) for bovine herpes virus. The frequencies of leptospiral serovars in buffaloes were as follows: 18.7% for Muenchen (n = 27), 10.4% for Hardjo LT (n = 15), 9.0% for Pyrogenes (n = 13), and 4.8% for Icterohaemorrhagiae (n = 7). Seropositive buffaloes were found in all 5 ranches studied. Logistic regression showed that cohabitation of buffaloes with cows was associated with infection with Leptospira (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.04–4.5; P = 0.03) and bovine herpesvirus (OR, 12.0; 95% CI, 4.0–36.2; P < 0.01).

This is the first study that provides serological evidence of N. caninum, Leptospira, and bovine herpesvirus type 1 infections in water buffaloes in Mexico. Our findings could be used to enhance preventive measures against these infections.

Prevalence of Cryptosporidium in small ruminants from Veracruz, Mexico

BACKGROUND

Cryptosporidiosis is a zoonotic disease caused by the protozoan parasite Cryptosporidium spp. that can affect domestic animal and human populations. In newborn ruminants, cryptosporidiosis is characterized by outbreaks of diarrhea, which can result in high morbidity and economic impact. The aim of the present study was to determine the prevalence of Cryptosporidium spp. in small ruminants from the Perote municipality in Veracruz State, Mexico. One hundred and sixty small ruminants (80 sheep and 80 goats) from eight farms located in four towns of the Perote municipality were examined following a cross-sectional study design. Stool samples were analyzed by a modification of the Faust centrifugation method, and the presence of Cryptosporidium spp. oocysts was examined using a modification of the Ziehl-Neelsen staining procedure. Bivariate and multivariate analyses were used to assess the association of Cryptosporidium infection and the general characteristics of the animals studied.

RESULTS

Overall, 112 (70%, 95% CI: 62.3-76.9) of the 160 small ruminants sampled were infected with Cryptosporidium spp. The prevalence of Cryptosporidium spp. infection in goats was 72.5% (95% CI: 61.4-81.9) and in sheep 67.5% (95% CI: 56.1-77.6). Small ruminants aged 1 month old had the highest (88.2%; 95% CI: 63.6-98.5) prevalence of infection. Prevalence varied from 60% to 85% among herds. Animal species, age, sex, breed, farm, town or cohabitation with cattle did not influence the prevalence of Cryptosporidium infection.

CONCLUSIONS

A high prevalence of infection with Cryptosporidium spp. was observed in small ruminants from the Perote municipality in Veracruz, Mexico. Infection was widely distributed among sheep and goats regardless of their age, breed or farm location. Further research is required to identify risk factors for, and to assess the veterinary public health significance of Cryptosporidium infection among sheep and goats in the Mexican state of Veracruz.

Pathogenic Landscape of Transboundary Zoonotic Diseases in the Mexico-US Border Along the Rio Grande

Transboundary zoonotic diseases, several of which are vector borne, can maintain a dynamic focus and have pathogens circulating in geographic regions encircling multiple geopolitical boundaries. Global change is intensifying transboundary problems, including the spatial variation of the risk and incidence of zoonotic diseases. The complexity of these challenges can be greater in areas where rivers delineate international boundaries and encompass transitions between ecozones. The Rio Grande serves as a natural border between the US State of Texas and the Mexican States of Chihuahua, Coahuila, Nuevo León, and Tamaulipas. Not only do millions of people live in this transboundary region, but also a substantial amount of goods and people pass through it everyday. Moreover, it occurs over a region that functions as a corridor for animal migrations, and thus links the Neotropic and Nearctic biogeographic zones, with the latter being a known foci of zoonotic diseases. However, the pathogenic landscape of important zoonotic diseases in the south Texas-Mexico transboundary region remains to be fully understood. An international perspective on the interplay between disease systems, ecosystem processes, land use, and human behaviors is applied here to analyze landscape and spatial features of Venezuelan equine encephalitis, Hantavirus disease, Lyme Borreliosis, Leptospirosis, Bartonellosis, Chagas disease, human Babesiosis, and Leishmaniasis. Surveillance systems following the One Health approach with a regional perspective will help identifying opportunities to mitigate the health burden of those diseases on human and animal populations. It is proposed that the Mexico-US border along the Rio Grande region be viewed as a continuum landscape where zoonotic pathogens circulate regardless of national borders.

Seroprevalence of Toxoplasma gondii infection in water buffaloes (Bubalus bubalis) in Veracruz State, Mexico and its association with climatic factors

Background

Infection with Toxoplasma gondii in water buffaloes (Bubalus bubalis) is of epidemiological importance because of the risk for transmission to humans. We sought to determine the seroprevalence of T. gondii infection in 339 water buffaloes in Veracruz State, Mexico using the modified agglutination test (MAT, cut off 1:25). Seroprevalence association with general characteristics of buffaloes and their environment was also investigated.

Results

Antibodies to T. gondii were found in 165 (48.7%) of the 339 buffaloes with MAT titers of 1:25 in 104, 1:50 in 52, and 1:100 in 9. Bivariate analysis showed that seroprevalence of T. gondii infection was similar in buffaloes regardless of their general characteristics i.e., age, sex, and breed. In contrast, the seroprevalence in buffaloes varied significantly with environmental characteristics including altitude, mean annual temperature, and mean annual rainfall of the municipalities studied. Multivariate analysis showed that T. gondii seropositivity in buffaloes was associated with a mean annual rainfall between 1266–1650 mm (OR = 1.84; 95% CI: 1.15-2.94; P = 0.01).

Conclusions

Results indicate that environmental characteristics may influence the seroprevalence of T. gondii infection in buffaloes. This is the first report on the seroprevalence of T. gondii infection in buffaloes in Mexico. Further research is needed to assess the risk for infection in humans associated with the ingestion of raw or undercooked meat from buffaloes infected with T. gondii.

High prevalence of Toxoplasma gondii antibodies in dogs in Veracruz, Mexico

BACKGROUND

Little is known concerning the prevalence of Toxoplasma gondii infection in dogs in Mexico. Here, we investigated antibodies to T. gondii and associated risk factors in 101 dogs from an animal shelter in Veracruz State, Mexico. Canine sera were assayed for T. gondii IgG antibodies by using the modified agglutination test (MAT, cut off 1:25).

RESULTS

Sixty eight (67.3%) of 101 dogs were seropositive with titers of 1:25 in 16, 1:50 in 8, 1:100 in 9, 1:200 in 10, 1:400 in 10, 1:800 in 10, 1:1600 in 3, and 1:3200 or higher in 2. None of the dogs' characteristics studied including age, sex, breed, and history of deworming, rabies vaccination and contact with cats was associated with seroprevalence of T. gondii infection.

CONCLUSION

Using the dogs as sentinel animals, the results indicate high contamination with T. gondii of the environment in Veracruz, Mexico. Results have public health implications, and further studies in Veracruz should be conducted to establish the sources of environmental contamination with T. gondii and to determine optimal preventive measures against T. gondii infection in humans.

Does home range use explain the relationship between group size and parasitism? A test with two sympatric species of howler monkeys

Group size is related to parasite infections in primates. This relationship probably reflects the fact that group size is associated with body contact between group members and with contact with contaminated items in the environment. The latter is highly associated with range use. In the present study we hypothesized that if infection by directly transmitted parasites (DTP) is mainly determined by the exposure of individuals to parasites that accumulate in the environment, and group size correlates negatively with the intensity of home range use, then smaller groups should be more infected by DTP. Additionally, groups that share a higher proportion of their home range with other groups should be more infected. To test our hypothesis we observed and collected fecal samples of two groups of Alouatta palliata (large group size) and two groups of A. pigra (small group size) that live sympatrically in a forest fragment located in Macuspana (Mexico). Group size was positively correlated with range area size and negatively correlated with the intensity of home range use. Range use variables were not related to either DTP prevalence or load. However, there were significant differences in DTP loads between groups, which were positively correlated with group size. Our results suggest that the intensity of home range use is a poor predictor of DTP infection parameters in groups with marked differences in size. Therefore, it is possible that the individual or combined effects of other ecological (e.g., microclimate), social (e.g., contact rate), or physiological (e.g., immune function) factors are more important in the dynamics of DTP in free-ranging primates.