Molecular characterization of Rickettsia spp., Bartonella spp., and Anaplasma phagocytophilum in hard ticks collected from wild animals in Benin, West Africa.

Tick and tick-borne pathogens constitute a growing veterinary and public health concern around the world. Ticks are considered natural reservoirs for tick-borne related pathogens and are equally responsible for the spread of infections in animals as well as humans. In this study, the presence of Rickettsia, Bartonella, and Anaplasma phagocytophilum was investigated in hard ticks collected from reptiles, birds, and wild mammalian animals. The sample collection was carried out between December 2020 and September 2021. Adult ticks (male and female) were collected from wild animals in six districts of southern Benin. Molecular analysis was used to verify the presence of pathogens in all the ticks collected from wild animals. A total of 504 ticks were collected and grouped into 115 different tick pools. The PCR analysis detected 19 out of 115 tick pools which turn out positive for Rickettsia spp. and 9/115 tick pools positive for Bartonella spp., while Anaplasma phagocytophilum DNA was not detected in any tick. Several of the tick species collected from our studied reptiles/wild mammalian animals could be potential sources of zoonotic pathogens when subjected to further investigation. Therefore, stringent attention should be established for tick infestation of reptiles/wild mammalian animals in order to put in place proper control and prevention measures for tick-borne diseases in the wild, which could serve as reservoirs in the infestation of domestic animals/humans in the event of any possible contact.

Molecular diagnosis of bovine tuberculosis on postmortem carcasses during routine meat inspection in Benin: GeneXpert® testing to improve diagnostic scheme.

Background and Aim: Bovine tuberculosis (TB) is a zoonotic disease of major public health importance, particularly in African countries, where control measures are limited or largely not applied. This study aimed to determine the accuracy of the currently used bovine TB diagnostic method at slaughterhouses in Benin; this is to contribute to the betterment and improvement in the epidemiological surveillance of the disease in the country. Materials and Methods: A total of 40 tissue samples were collected from meat/viscera (lung, liver, heart, kidney, and the gastro-intestinal tract tissues) at Cotonou slaughterhouses from ruminants suspected to be infected with bovine TB during routine meat inspection. The collected samples were analyzed using GeneXpert testing technique as a reference method. Results: Twenty-six samples tested positive out of the 40 suspected tissue samples collected by GeneXpert diagnostic technique; this shows the limitation of the routine meat inspection in detecting bovine TB as currently performed in Benin. Conclusion: The outcome of the use of the molecular technique, therefore, supports the importance of the use of a molecular tool alongside the routine meat inspection for a better understanding of the epidemiology of bovine TB in Benin. However, more robust technical and policy efforts are needed for a sustainable implementation of such a strategy.

Molecular epidemiology of peste des petits ruminants virus in Nigeria: An update.

Peste des petits ruminants (PPR) is a highly contagious viral disease that mainly affects goats and sheep in Asia, Africa and the Middle East. The PPR virus (PPRV) can be classified into four genetically distinct lineages (I, II, III and IV). All have been historically present in Africa, except the Asian lineage IV that has been spreading across the globe and across Africa in recent decades. Previous studies have identified the presence of lineage IV in Nigeria since 2010. In the present study, samples were taken from 429 small ruminants with PPR symptoms across Nigeria in 2017-2020 to provide an update on the distribution and genetic diversity of PPRV in the country. Sequences from a portion of the PPRV nucleoprotein (N) gene were obtained from 91 samples, 90 belonging to lineage IV and one to lineage II. Phylogenetic analysis identified at least four lineage IV sub-clusters in Nigeria, grouping samples across multiple regions. Our results suggest extensive endemic circulation of a wide range of PPRV strains across Nigeria and across borders with neighbouring countries, underlining the difficulty involved in controlling the disease in the region.

Treatment of Girolando cattle dermatophilosis using a combination of different plant extracts in the municipality of Abomey-Calavi, Republic of Benin.

BACKGROUND AND AIM: Dermatophilosis is a bacterial infection of the skin of animals. It is prevalent worldwide and is caused by Dermatophilus congolensis. The study aimed to assess the therapeutic efficacy of different mixtures prepared with indigenous phytogenetic extracts from Benin in the management and treatment of Girolando cattle that showed high sensitivity to the disease compared to any other known cattle breed in Benin. MATERIALS AND METHODS: Consequently, two types of extact mixtures (extract mixture 1=Elaeis guineensis kernel oil + essential oil of Ocimum gratissimum + sap of Jatropha multifidi; extract mixture 2= O. gratissimum + sap extract of J. multifida) of 20% concentration were prepared and tested on eight Girolando cattle. Two different parts of the affected skin with acute lesions of dermatophilosis were debrided, and 0.5 mL of each of the extract mixture was applied per square centimeter of a single zone of the affected skin. RESULTS: Both extracts mixtures were found to possess significant wound healing properties compared to the control (procaine G penicillin). However, the extract mixture 1, which was made up of Elaeis guineensis kernel oil, essential oil of O. gratissimum and sap of J. multifida (Linn), showed a better result. This was evident by increase in the rate of wound contraction and healing without recurrence 2 weeks after the end of the experiment and the subsequent immediate manifestation of hair or hair growth at the affected area. CONCLUSION: The preliminary findings of this study are very promising. Extract mixture 1 could serve as an alternative in the treatment or management of bovine dermatophilosis in Benin and other dermatophilosis endemic areas of the world. However, in vitro testing and sensitivity against isolated D. congolensis organism using extract mixture 1 as well as cost implications should be studied.

Phenotypic and genotypic characterization of dog tick Rhipicephalus sanguineus sensu lato (Acari: Ixodidae) resistance to deltamethrin in Benin.

The aim of this study was to evaluate the phenotypic and genotypic resistance of Rhipicephalus sanguineus sensu lato to deltamethrin in dogs in the municipality of Natitingou in Benin. In this study, the collection and identification of ticks, Larval Packet Test and specific allele PCR were the main methods used. A total of 41 dogs were examined and 420 ticks were collected in six areas which includes: Tchrimina, Yokossi, Boriyoure, Berécingou, Péporiyakou and Perma. Three species of ticks were identified and they include: R. sanguineus s.l., Rhipicephalus microplus and Haemaphysalis spp. However, R. sanguineus s.l. was the most abundant tick species (9.85) and had the highest parasitic intensity (10.36). The results of the Larval Packet Test showed that the larvae of R. sanguineus s.l. developed a phenotypic resistance against deltamethrin, particularly in the Bérécingou area where resistance ratios of LC50 and LC95 of R. sanguineus s.l. compared to a susceptible strain were 1.591 (1.025-3.054) and 65.339 (20.235-579.825) respectively. The molecular study of the sodium channel gene revealed three genotypes namely the susceptible genotype (SS), the heterozygous genotype (SR) and the resistant genotype (RR), which correlates with the phenotypic results. This information is fundamental to improve monitoring and resistance management strategies of R. sanguineus s.l. ticks to pyrethroids.

Wide circulation of peste des petits ruminants virus in sheep and goats across Nigeria.

Peste des petits ruminants (PPR) is a highly contagious viral disease that mainly affects goats and sheep in Asia, Africa and the Middle East, and threatens Europe [R.E.1]. The disease is endemic on the African continent, particularly in West Africa, and is a major factor driving food insecurity in low-income populations. The aim of this research study was to carry out surveillance, genetic characterisation and isolation of recently circulating PPR viruses (PPRV) in sheep and goats from the six agro-ecological zones of Nigeria. A total of 268 post-mortem tissue samples of lung and mesenteric ganglia were collected from clinically suspected sheep and goats in 18 different states, of which five never previously sampled. The presence of PPRV was confirmed using a reverse-transcription coupled with a polymerase chain reaction (RT-PCR) assay. A total of 72 samples, 17 sheep (6%) and 55 goats (21%), were found to be PPR positive. Positive samples were distributed in almost all states, except Kano, where PPR was detected in previous studies. The PPRV-positive samples were further confirmed by sequencing or virus isolation in areas where the infection had never previously been detected. These results confirm the active circulation of PPRV across all six agro-ecological zones of Nigeria, and consequently, the need for introducing strict measures for the control and prevention of the disease in the country.

Peste des petits ruminants in Africa: Meta-analysis of the virus isolation in molecular epidemiology studies.

Peste des petits ruminant (PPR) is a highly contagious, infectious viral disease of small ruminant species which is caused by the peste des petits ruminants virus (PPRV), the prototype member of the Morbillivirus genus in the Paramyxoviridae family. Peste des petits ruminant was first described in West Africa, where it has probably been endemic in sheep and goats since the emergence of the rinderpest pandemic and was always misdiagnosed with rinderpest in sheep and goats. Since its discovery PPR has had a major impact on sheep and goat breeders in Africa and has therefore been a key focus of research at the veterinary research institutes and university faculties of veterinary medicine in Africa. Several key discoveries were made at these institutions, including the isolation and propagation of African PPR virus isolates, notable amongst which was the Nigerian PPRV 75/1 that was used in the scientific study to understand the taxonomy, molecular dynamics, lineage differentiation of PPRV and the development of vaccine seeds for immunisation against PPR. African sheep and goat breeds including camels and wild ruminants are frequently infected, manifesting clinical signs of the disease, whereas cattle and pigs are asymptomatic but can seroconvert for PPR. The immunisation of susceptible sheep and goats remains the most effective and practical control measure against PPR. To carry out PPR vaccination in tropical African countries with a very high temperature, a thermostable vaccine using the rinderpest lyophilisation method to the attenuated Nigeria 75/1 PPR vaccine strain has been developed, which will greatly facilitate the delivery of vaccination in the control, prevention and global eradication of PPR. Apart from vaccination, other important questions that will contribute towards the control and prevention of PPR need to be answered, for example, to identify the period when a susceptible naïve animal becomes infectious when in contact with an infected animal and when an infectious animal becomes contagious.

Comparison of nucleotide sequences of recent and previous lineages of peste-des-petits-ruminants viruses of sheep and goats in Nigeria.

Peste-des-petits-ruminants virus (PPRV) is a highly contagious, fatal and economically important viral disease of small ruminants that is still endemic and militates against the production of sheep and goats in endemic areas of the world. The aim of this study was to describe the viral strains within the country. This was carried out by collecting tissue and swab samples from sheep and goats in various agro-ecological zones of Nigeria. The phylogeny of archived PPRV strains or isolates and those circulating and causing recent outbreaks was determined by sequencing of the nucleoprotein (N)-gene. Twenty tissue and swab samples from apparently healthy and sick sheep and goats were collected randomly from 18 states, namely 3 states in each of the 6 agro-ecological zones visited. A total of 360 samples were collected. A total of 35 samples of 360 (9.7%) tested positive by reverse transcriptase-polymerase chain reaction, of which 25 were from oculo-nasal swabs and 10 were from tissue samples. Neighbour-joining phylogenetic analysis using Phylogenetic Analysis Using Parsimony (PAUP) identified four different lineages, that is, lineages I, II, III and IV. Interestingly, the Nigerian strains described in this study grouped in two separate major lineages, that is, lineages II and IV. Strains from Sokoto, Oyo, Plateau and Ondo states grouped according to the historical distribution of PPRV together with the Nigerian 75/1 strain of lineage II, while other strains from Sokoto, Oyo, Plateau, Akwa-Ibom, Adamawa, Kaduna, Lagos, Bauchi, Niger and Kano states grouped together with the East African and Asian strains of lineage IV. This finding confirms that both lineage II and IV strains of PPRV are circulating in Nigeria. Previously, only strains of lineage II were found to be present in the country.