Prevalence and genetic diversity of Bartonella spp. in wild small mammals from South Africa.

Bartonella spp. are intracellular bacteria associated with several re-emerging human diseases. Small mammals play a significant role in the maintenance and spread of Bartonella spp. Despite the high small mammal biodiversity in South Africa, there is limited epidemiological information regarding Bartonella spp. in these mammals. The main aim of this study was to determine the prevalence and genetic diversity of Bartonella spp. from wild small mammals from 15 localities in 8 provinces of South Africa. Small mammals (n = 183) were trapped in the Eastern Cape, Free State, Gauteng, Limpopo, Mpumalanga, Northern Cape, North West, and Western Cape provinces of South Africa between 2010 and 2018. Heart, kidney, liver, lung, and spleen were harvested for Bartonella DNA screening, and prevalence was determined based on the PCR amplification of partial fragments of the 16S-23S rRNA intergenic spacer (ITS) region, gltA, and rpoB genes. Bartonella DNA was detected in Aethomys chrysophilus, Aethomys ineptus, Gerbillurus spp., Lemniscomys rosalia, Mastomys coucha, Micaelamys namaquensis, Rhabdomys pumilio, and Thallomys paedulcus. An overall prevalence of 16.9% (31/183, 95% CI: 12.2%-23%) was observed. Bartonella elizabethae, Bartonella grahamii, and Bartonella tribocorum were the zoonotic species identified, while the remaining sequences were aligned to uncultured Bartonella spp. with unknown zoonotic potential. Phylogenetic analyses confirmed five distinct Bartonella lineages (I-V), with lineage IV displaying strong M. coucha host specificity. Our results confirm that South African wild small mammals are natural reservoirs of a diverse assemblage of Bartonella spp., including some zoonotic species with high genetic diversity, although prevalence was relatively low.IMPORTANCESmall mammals play a significant role in the maintenance and spread of zoonotic pathogens such as Bartonella spp. Despite the high small mammal biodiversity in southern Africa including South Africa, there is limited epidemiological information regarding Bartonella spp. in these mammals across the country. Results from our study showed the liver and spleen had the highest positive cases for Bartonella spp. DNA among the tested organs. Bartonella elizabethae, B. grahamii, and B. tribocorum were the three zoonotic species identified and five distinct Bartonella lineages (I-V) were confirmed through phylogenetic analyses. To the best of our knowledge, this study presents the first extensive nuclear diversity investigation of Bartonella spp. in South African small mammals in South Africa.

Low genetic diversity and population structuring of Amblyomma hebraeum and Rickettsia africae from coastal and inland regions in the Eastern Cape Province of South Africa.

Amblyomma hebraeum is the main vector of Rickettsia africae, the causative agent of African tick bite fever in southern Africa. Because pathogen dispersal is known to be influenced by tick adaptations to climate or host species, this study aimed to analyse the genetic diversity of A. hebraeum and R. africae infection of ticks collected from cattle in the Eastern Cape province of South Africa. DNA was extracted, amplified, and sequenced for the COI and ITS2 markers from A. hebraeum samples and the 17 kDa and ompA genes for rickettsial detection. Between six and ten haplotypes were identified from 40 COI and 31 ITS2 sequences; however, no population structuring was observed among sites (ΦST = 0.22, p < 0.05). All A. hebraeum isolates clustered with southern Africa GenBank isolates. Rickettsia africae was detected in 46.92% (95% CI = 41%-53%, n = 260) of ticks. All R. africae isolates clustered with strain PELE and Chucks, which were reported previously from South Africa. These results confirm that A. hebraeum populations are undergoing a recent population expansion driven by cattle movement, facilitating local and long dispersal events across the Eastern Cape province.

Metabolomics of Type 2 Diabetes Mellitus in Sprague Dawley Rats-In Search of Potential Metabolic Biomarkers.

Type 2 diabetes mellitus (T2DM) is an expanding global health concern, closely associated with the epidemic of obesity. Individuals with diabetes are at high risk for microvascular and macrovascular complications, which include retinopathy, neuropathy, and cardiovascular comorbidities. Despite the availability of diagnostic tools for T2DM, approximately 30-60% of people with T2DM in developed countries are never diagnosed or detected. Therefore, there is a strong need for a simpler and more reliable technique for the early detection of T2DM. This study aimed to use a non-targeted metabolomic approach to systematically identify novel biomarkers from the serum samples of T2DM-induced Sprague Dawley (SD) rats using a comprehensive two-dimensional gas chromatography coupled with a time-of-flight mass spectrometry (GCxGC-TOF/MS). Fifty-four male Sprague Dawley rats weighing between 160-180 g were randomly assigned into two experimental groups, namely the type 2 diabetes mellitus group (T2DM) (n = 36) and the non-diabetic control group (n = 18). Results from this study showed that the metabolite signature of the diabetic rats was different from that of the non-diabetic control group. The most significantly upregulated metabolic pathway was aminoacyl-t-RNA biosynthesis. Metabolite changes observed between the diabetic and non-diabetic control group was attributed to the increase in amino acids, such as glycine, L-asparagine, and L-serine. Aromatic amino acids, including L-tyrosine, were associated with the risk of future hyperglycemia and overt diabetes. The identified potential biomarkers depicted a good predictive value of more than 0.8. It was concluded from the results that amino acids that were associated with impaired insulin secretion were prospectively related to an increase in glucose levels. Moreover, amino acids that were associated with impaired insulin secretion were prospectively related to an increase in glucose levels.

Metabolomics (Non-Targeted) of Induced Type 2 Diabetic Sprague Dawley Rats Comorbid with a Tissue-Dwelling Nematode Parasite.

Type 2 diabetes is a non-communicable metabolic syndrome that is characterized by the dysfunction of pancreatic ß-cells and insulin resistance. Both animal and human studies have been conducted, demonstrating that helminth infections are associated with a decreased prevalence of type 2 diabetes mellitus (T2DM). However, there is a paucity of information on the impact that helminths have on the metabolome of the host and how the infection ameliorates T2DM or its progression. Therefore, this study aimed at using a non-targeted metabolomics approach to systematically identify differentiating metabolites from serum samples of T2DM-induced Sprague Dawley (SD) rats infected with a tissue-dwelling nematode, Trichinella zimbabwensis, and determine the metabolic pathways impacted during comorbidity. Forty-five male SD rats with a body weight between 160 g and 180 g were used, and these were randomly selected into control (non-diabetic and not infected with T. zimbabwensis) (n = 15) and T2DM rats infected with T. zimbabwensis (TzDM) (n = 30). The results showed metabolic separation between the two groups, where d-mannitol, d-fructose, and glucose were upregulated in the TzDM group, when compared to the control group. L-tyrosine, glycine, diglycerol, L-lysine, and L-hydroxyproline were downregulated in the TzDM group when compared to the control group. Metabolic pathways which were highly impacted in the TzDM group include biotin metabolism, carnitine synthesis, and lactose degradation. We conclude from our study that infecting T2DM rats with a tissue-dwelling nematode, T. zimbabwensis, causes a shift in the metabolome, causing changes in different metabolic pathways. Additionally, the infection showed the potential to regulate or improve diabetes complications by causing a decrease in the amino acid concentration that results in metabolic syndrome.

Effect of Schistosoma haematobium infection on the cognitive functions of preschool age children and benefits of treatment from an endemic area in Zimbabwe.

BACKGROUND: Schistosomiasis is known to affect the cognitive functions of children, however, but there is paucity of information on its impact on early childhood development in developing countries where the disease is endemic. This study aimed at determining the effects of schistosomiasis due to Schistosoma haematobium on early childhood development in children below 5 years old from Murewa District, Zimbabwe, including the benefits of treatment. METHODS: Preschool age children (PSAC) under the age of 5 years were screened at baseline and at 6 months post-treatment for S. haematobium infections diagnosed using the urine filtration method. Cognitive domains were assessed using the Griffith Mental Developmental Scales III on 136 PSAC. Multivariate logistic regression was used to determine the level of association between S. haematobium infection and performance in the cognitive domains adjusting for confounding factors (i.e. nutrition, hemoglobin levels, gender and age). Median Development Quotient scores of each cognitive domain at baseline and at 6 months post-treatment were compared and quantified. RESULTS: After adjusting for confounding factors, PSAC infected with S. haematobium had greater odds of having lower scores in the Foundation of Learning Domain (OR = 3.9, p = 0.008), Language and Communication Domain (OR = 3.2, p = 0.017), Eye-Hand Coordination Domains (OR = 10.7, p = 0.001), Personal-Social-Emotional Domain (19.3, p = 0.001) and in the Overall General Development Domain (7.2, p = 0.011). Improvement of cognitive performance was observed at 6 months post treatment in the following Domains; Language and Communication Domain (p = 0.003), Eye-Hand Coordination Domain (p = 0.02) and General Development Domain (p = 0.006). CONCLUSION: The study showed that S. haematobium infection in PSAC is associated with lower cognitive scores in the Foundation of Learning, Language and Communication, Eye-Hand Coordination, Personal-Social-Emotional and in the Overall General Development domains. Our results strengthen the call for inclusion of PSAC in routine deworming programs for the control of urinary schistosomiasis and the need to develop locally validated tools to monitor early child development in endemic areas where resources are limited.

Knowledge and practices on consumption of free-range chickens in selected rural communities of KwaZulu-Natal, South Africa, with focus on zoonotic transmission of Toxoplasma gondii and Toxocara spp.

Chickens are a host to a variety of pathogens of zoonotic importance and this depends more on the husbandry system practiced. Toxoplasma gondii and Toxocara spp which are more prevalent in free-range chickens (FRC) can be acquired by humans via the ingestion of raw or undercooked meat (muscle) and/or viscera contaminated with infective stages of T. gondii and Toxocara spp. This study aimed to assess knowledge and practices on the household consumption of FRC meat and viscera by rural communities in KwaZulu-Natal (KZN) province, South Africa, as a risk factor in the transmission of zoonotic pathogens with special emphasis on T. gondii and Toxocara spp. A cross-sectional study was conducted on twenty (20) randomly selected households in four selected communities located on the northern coast (Gingindlovu and Ozwathini) and southern coast (uMzinto and Shongweni) of KZN province using a semi-structured questionnaire. To determine the presence of selected zoonotic pathogens in FRC, birds were purchased from randomly selected households in the study localities for sacrifice. Brain tissues were collected and subjected to molecular detection of T. gondii using TOX4 and TOX5 primers while other tissues and organs that were collected were subjected to molecular detection of Toxocara spp using Nem 18S primers. Questionnaire data were analyzed using the statistical package for social sciences (SPSS) version 25.0. Descriptive and chi-square statistics were used to assess knowledge and practices related to FRC consumption and zoonosis transmission. Molecular results showed four positive samples for T. canis from Gingindlovu (n = 1), uMzinto (n = 1), and Shongweni (n = 2). The role of FRC consumption in zoonosis transmission is discussed.

Epidemiology, prevention and control of gastrointestinal helminths of small ruminants in the Caribbean region-a scoping review.

This review gathered information from peer-reviewed publications on the epidemiology, prevention and control of gastrointestinal helminths (GIHs) parasites of small ruminants in the Caribbean region from 1990 to 2021. Literature search was performed on four electronic databases using a combination of search terms and Boolean operators. Results showed that gastrointestinal nematodes (GINs) were the most common parasites, with seven genera documented across six reviewed countries. Haemonchus contortus was the most common species occurring in all six countries, and predominant in occasions where mixed infections were observed. Moniezia species were the only Platyhelminth species documented in Trinidad and Grenada. The overall prevalence of GIH infections was observed to be high in goats than in sheep. A high level of anthelminthic resistance (AR) with H. contortus was reported, whilst other nematodes showed to be effectively controlled by one or more anthelmintic drugs. FAMACHA© method was applied in the identification of anaemic animals for selective treatment, hence contributing to the decreased use of anthelmintic drugs. There is a need for national surveys of GIHs and AR in small ruminants in the Caribbean countries. Surveys, coupled with the use of molecular techniques to detect and identify species of GIHs present in the Caribbean region, as well as their epidemiology which will inform development of integrated control strategies is recommended. There is also a need to create awareness to small ruminant farmers in the region on the prevailing challenge of AR and limit wanton use of anthelminthics to reduce or prevent AR in small ruminants.

Knowledge, attitudes and practices on African tick bite fever of rural livestock communities living in a livestock-wildlife interface area in the Eastern Cape Province of South Africa.

BACKGROUND: African tick bite fever (ATBF) caused by Rickettsia africae and transmitted by Amblyomma spp. ticks is one of the zoonotic tick-borne fevers from the spotted fever group (SFG) of rickettsiae, which is an emerging global health concern. There is paucity of information regarding the occurrence and awareness of the disease in endemic rural livestock farming communities living in livestock-wildlife interface areas in South Africa. METHODS: The purpose of the study was to assess the level of knowledge, attitudes and practices on ticks and ATBF infection from a community living in livestock-wildlife interface areas in South Africa. A focus group discussion (FGD) was carried out followed by verbal administration of a standardized semi-structured questionnaire a month later to 38 rural livestock farmers (23 from Caquba area and 15 from Lucingweni area where A. hebraeum was absent). An FGD was conducted in Caquba (situated at the livestock-wildlife interface where Amblyomma hebraeum was prevalent on cattle and infected with Rickettsia africae) in the O.R. Tambo district of the Eastern Cape province of South Africa. RESULTS: Results from the FGD and questionnaire survey showed that participants from the two rural communities were not aware of ATBF and were not aware that ticks are vectors of the disease. Respondents from Caquba reported of having frequent exposure to tick bites (91.3%, 21/23) specifically from the anthropophilic A. hebrauem which they were able to identify as Qwelagqibe in IsiXhosa (their vernacular). Thirteen out of 15 (86.7%) of respondents from Lucingweni reported that they had never been bitten by ticks, which corresponded with the absence of A. hebraeum from their locality as evidenced from results of a concurrent study on prevalence of ticks on livestock in the area. Both communities confirmed to being "very concerned" of tick bites and we presume this was more related to the localized wounds from the bites than to the diseases transmitted by the ticks. CONCLUSIONS: We recommend future studies encompassing seroprevalence of ATBF in Caquba and other communities at risk in South Africa including establishing surveillance systems to monitor the seasonal infection rates in ticks, cattle and humans.

Consumer knowledge and practices to pork safety in two Taenia solium cysticercosis endemic districts in Eastern Cape Province of South Africa.

BACKGROUND: Globally, Taenia solium can cause cysticercosis in humans (including neurocysticercosis) and in pigs through ingestion of eggs and taeniasis in humans through ingestion of raw/undercooked pork contaminated with mature cysts. It is now recognised globally as one of the most prevalent food-borne parasitic diseases. The majority of cases have been reported in developing countries where consumption of food produced under unhygienic conditions is prevalent, exacerbated by lack of food safety education. The aim of this study was to determine the knowledge and practices of consumers towards pork safety in two districts of the Eastern Cape Province of South Africa, where T. solium cysticercosis is endemic in pigs and humans. METHODS: Three-hundred-and-sixty-one (361) participants were conveniently interviewed on consumer knowledge (harmfulness of T. solium cysticercosis, ability to identify cysts, trustworthiness of registered butcheries and legal requirements) and practices (storage of pork and method(s) of cooking pork safely) through a structured questionnaire. Chi-square for association of variables was used to compare differences in the districts. RESULTS: Overall, 73.1% of the study group from both districts agreed that pork forms an important part of their diet. Consumers (54.2%: 189/349) agreed that pork infected with T. solium cysts could be harmful, and 57.3% (188/328) indicated their inability to identify T. solium cysts in pork when slaughtered at home. Although 69.5% (234/352) trusted pork bought from butcheries, only 52.2% (187/358) were aware that butcheries must present a registration certificate in order to operate. This coincides with the fact that very few (< 10%) were aware of the legal requirements in terms of disease control, slaughter and food preparation. Most consumers (88.7%: 268/302) kept pork in the fridge and only 11.3% (34/302) kept it in a freezer (p = 0.02). Although not significantly different between the districts (p = 0.15), consumers in Alfred Nzo (71.4%: 152/213) and OR Tambo (61.2%: 74/12) mostly cooked pork as a stew, followed by braai/barbeque and frying or baking. This was in line with the fact that consumers in Alfred Nzo (79%: 147/186) and OR Tambo (80.8%: 120) preferred well-cooked pork; the main reason for this was the belief that cooking kills germs (43.6%: 121/277) followed by rendering the meat tasty (26.4%: 73/277). CONCLUSIONS: Consumers surveyed in the two districts were somewhat aware that T. solium cysticercosis could be harmful, although some were not able to identify T. solium cysts in pork. They also lacked sufficient knowledge regarding butchery certification and other legal requirements related to disease control, slaughter and food preparation. Practices related to cooking have the potential to promote the transmission of human taeniasis and the fact that most respondents preferred stewed pork could be a positive sign, as the cysts are destroyed during the cooking process. Results from this study are useful for the development of a control and prevention strategy targeted towards consumers, and the creation of awareness of food safety, with special emphasis on T, solium cysticercosis.

Smallholder pig farming education improved community knowledge and pig management in Angónia district, Mozambique.

Education on pig farming has been recognized as an important method of transferring knowledge and improving production among smallholder pig producers in rural settings, but the effectiveness of this in different rural settings remains unknown. A community-based intervention trial on smallholder pig farmers was conducted with the aim of evaluating the effectiveness of pig farming education. Baseline information was collected using interview-based questionnaires and observations regarding pig welfare and husbandry practices followed by participatory pig farming education and field demonstrations. The study was carried out between May 2014 and May 2016 and involved 90 smallholder pig farmers from six villages in Angónia district, of Tete province in Mozambique. The baseline questionnaire among several aspects regarding pig management highlighted that most farmers had an overall knowledge on aspects of transmission (55.1%) and prevention (48.9%) of African swine fever (ASF), porcine cysticercosis (PC) transmission (8.2%), and field diagnosis (36.7%), and they were not aware of the zoonotic potential of PC or the basic husbandry procedures of pigs kept under permanent confinement. Forty-nine of the 90 farmers enrolled, participated in the pig farming education, which provided the basis for making a comparison between trained (54%) and non-trained (46%) pig farmers. Since knowledge for ASF transmission (P < 0.036), pig pen design (P < 0.014), reasons for confine the pigs (P < 0.016), as well as the adoption of the new introduced pig pen model (P < 0.025), and the practices of acceptable, good hygiene of the pig pen (P < 0.009 and P < 0.014, respectively), improved significantly in both groups, a remarkable spill-over was observed, proving villagers capable of transferring knowledge within the villages. However, water provision and total confinement in both groups were still not practiced by the most farmers following the pig farming education (P > 0.174 and 0.254). It is concluded that despite improved knowledge, the farmers failed to follow several recommendations, most likely due to poverty such as lack of basic resources like food and water, which even the farmers themselves lacked for their day to day living.

Isolation, characterization, and biological evaluation of a potent anti-malarial drimane sesquiterpene from Warburgia salutaris stem bark.

BACKGROUND: Malaria continues to be a global burden as the efficacy of most commercial anti-malarial drugs has been compromised by the evolution of parasite resistance. With the urgent need created for the development of alternative and more efficient anti-malarial drugs, this study focused on the evaluation of anti-malarial agents of the Warburgia salutaris stem bark. METHODS: The stem bark was extracted with dichloromethane followed by silica gel column chromatography that led to the isolation of iso-mukaadial acetate, a drimanoid sesquiterpene. This compound was characterized by spectroscopic analysis (1H NMR, 13C NMR, IR and MS), and its structure was confirmed by X-ray crystallography. In vitro anti-plasmodial activity was investigated using a chloroquine sensitive NF54 Plasmodium falciparum strain. Cytotoxicity was measured using the MTT assay on HEK239 and HEPG2 cell lines. Chloroquine-sensitive Plasmodium berghei was used to infect Sprague-Dawley rats for in vivo studies. The W. salutaris crude extract and iso-mukaadial acetate were administered orally at 0.5; 1.5, 2.5 and 5 mg/kg, chloroquine was used as the reference drug. Determination of percentage parasitaemia, haematological parameters, and rat body weights was done throughout the experimental study period. RESULTS: The crude extract and iso-mukaadial acetate showed very good activity on the inhibition of parasite growth (IC50 0.01 ± 0.30 µg/ml) and (IC50 0.44 ± 0.10 µg/ml), respectively, with iso-mukaadial acetate having cytotoxicity activity of 36.7 ± 0.8 and 119.2 ± 8.8 (µg/ml) on HEK293 and HEPG2 cells, respectively. The crude extract and iso-mukaadial acetate reduced percentage parasitaemia in a dose-dependent manner in comparison to the control. There were no significant differences in the haematological parameters in all the experimental groups in comparison to control group. This study proves that W. salutaris contains components (including iso-mukaadial acetate) that exhibit anti-malarial activity. This study scientifically validates the use of this plant in folk medicine. CONCLUSIONS: This study proves that Warburgia salutaris contains components (including iso-mukaadial acetate) that exhibit anti-malarial activity and scientifically validates the use of this plant in folk medicine.

Malaria incidence trends and their association with climatic variables in rural Gwanda, Zimbabwe, 2005-2015.

BACKGROUND: Malaria is a public health problem in Zimbabwe. Although many studies have indicated that climate change may influence the distribution of malaria, there is paucity of information on its trends and association with climatic variables in Zimbabwe. To address this shortfall, the trends of malaria incidence and its interaction with climatic variables in rural Gwanda, Zimbabwe for the period January 2005 to April 2015 was assessed. METHODS: Retrospective data analysis of reported cases of malaria in three selected Gwanda district rural wards (Buvuma, Ntalale and Selonga) was carried out. Data on malaria cases was collected from the district health information system and ward clinics while data on precipitation and temperature were obtained from the climate hazards group infrared precipitation with station data (CHIRPS) database and the moderate resolution imaging spectro-radiometer (MODIS) satellite data, respectively. Distributed lag non-linear models (DLNLM) were used to determine the temporal lagged association between monthly malaria incidence and monthly climatic variables. RESULTS: There were 246 confirmed malaria cases in the three wards with a mean incidence of 0.16/1000 population/month. The majority of malaria cases (95%) occurred in the > 5 years age category. The results showed no correlation between trends of clinical malaria (unconfirmed) and confirmed malaria cases in all the three study wards. There was a significant association between malaria incidence and the climatic variables in Buvuma and Selonga wards at specific lag periods. In Ntalale ward, only precipitation (1- and 3-month lag) and mean temperature (1- and 2-month lag) were significantly associated with incidence at specific lag periods (p < 0.05). DLNM results suggest a key risk period in current month, based on key climatic conditions in the 1-4 month period prior. CONCLUSIONS: As the period of high malaria risk is associated with precipitation and temperature at 1-4 month prior in a seasonal cycle, intensifying malaria control activities over this period will likely contribute to lowering the seasonal malaria incidence.

Micro-spatial distribution of malaria cases and control strategies at ward level in Gwanda district, Matabeleland South, Zimbabwe.

BACKGROUND: Although there has been a decline in the number of malaria cases in Zimbabwe since 2010, the disease remains the biggest public health threat in the country. Gwanda district, located in Matabeleland South Province of Zimbabwe has progressed to the malaria pre-elimination phase. The aim of this study was to determine the spatial distribution of malaria incidence at ward level for improving the planning and implementation of malaria elimination in the district. METHODS: The Poisson purely spatial model was used to detect malaria clusters and their properties, including relative risk and significance levels at ward level. The geographically weighted Poisson regression (GWPR) model was used to explore the potential role and significance of environmental variables [rainfall, minimum and maximum temperature, altitude, Enhanced Vegetation Index (EVI), Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), rural/urban] and malaria control strategies [indoor residual spraying (IRS) and long-lasting insecticide-treated nets (LLINs)] on the spatial patterns of malaria incidence at ward level. RESULTS: Two significant clusters (p < 0.05) of malaria cases were identified: (1) ward 24 south of Gwanda district and (2) ward 9 in the urban municipality, with relative risks of 5.583 and 4.316, respectively. The semiparametric-GWPR model with both local and global variables had higher performance based on AICc (70.882) compared to global regression (74.390) and GWPR which assumed that all variables varied locally (73.364). The semiparametric-GWPR captured the spatially non-stationary relationship between malaria cases and minimum temperature, NDVI, NDWI, and altitude at the ward level. The influence of LLINs, IRS and rural or urban did not vary and remained in the model as global terms. NDWI (positive coefficients) and NDVI (range from negative to positive coefficients) showed significant association with malaria cases in some of the wards. The IRS had a protection effect on malaria incidence as expected. CONCLUSIONS: Malaria incidence is heterogeneous even in low-transmission zones including those in pre-elimination phase. The relationship between malaria cases and NDWI, NDVI, altitude, and minimum temperature may vary at local level. The results of this study can be used in planning and implementation of malaria control strategies at district and ward levels.

In vivo effects of diabetes, insulin and oleanolic acid on enzymes of glycogen metabolism in the skin of streptozotocin-induced diabetic male Sprague-Dawley rats.

The skin is the largest organ in the body and diabetes induces pathologic changes on the skin that affect glucose homeostasis. Changes in skin glycogen and glucose levels can mirror serum glucose levels and thus the skin might contribute to whole body glucose metabolism. This study investigated the in vivo effects of diabetes, insulin and oleanolic acid (OA) on enzymes of glycogen metabolism in skin of type 1 diabetic rats. Diabetic and non-diabetic adult male Sprague-Dawley rats were treated with a single daily dose of insulin (4 IU/kg body weight), OA (80 mg/kg body weight) and a combination of OA + insulin for 14 days. Glycogen phosphorylase (GP) expression; and GP, glycogen synthase (GS) and hexokinase activities as well glycogen levels were evaluated. The results suggest that diabetes lowers hexokinase activity, GP activity and GP expression with no change in GS activity whilst the treatments increased GP expression and the activities of hexokinase, GP and GS except for the GS activity in OA treated rats. Glycogen levels were increased slightly by diabetes as well as OA treatment. In conclusion diabetes, OA and insulin can lead to changes in GS and GP activities in skin without significantly altering the glycogen content. We suggest that the skin may contribute to whole body glucose homeostasis particularly in disease states.

The prevalence and infection rates of amphistome species in intermediate snail hosts: a systematic review and meta-analysis.

The systematic review and meta-analysis were conducted to determine the estimates of the prevalence and infection rates of natural and experimental infections of amphistome species in intermediate host snails (IHs) across different continents. A search of peer-reviewed literature on natural and experimental infections of freshwater snails with amphistome species was conducted from four electronic databases from 1984 to 2023. The estimates of the prevalence and/or infection rates were based on 36 eligible peer-reviewed articles, which met the inclusion criteria and reported on natural and experimental infections of amphistome species in freshwater snails. The results showed that a total of 1,67,081 snail species from the peer-reviewed articles were examined for natural infections and 7,659 snail species for experimental infections. The overall pooled prevalence of amphistome infections from naturally infected snails was 2% (95% CI: 0-4), while the overall pooled prevalence of amphistome infections from infections was 40% (95% CI: 18-64). The highest pooled prevalence of natural infection was 3%, which was recorded in Europe (95% CI: 1-7%). The highest overall prevalence of naturally infected amphistome was 6% (95% CI: 0-20%) for Paramphistomum epiclitum. The Americas had the highest pooled prevalence of experimental amphistome infection among freshwater snails (66%; 95% CI: 26-96%). The highest pooled infection rate of 65% (95% CI: 12-100%) was recorded for Paramphistomum cervi in experimental infections. Galba truncatula was the only snail that qualified for meta-analysis for natural infection with Calicophoron daubneyi, with a pooled prevalence of 3% (95% CI: 1-8%). Galba truncatula infected with C. daubneyi and P. cervi, and Bulinus tropicus infected with Calicophoron microbothrium in the experimental infection qualified for the meta-analysis, with an overall infection rate of 66% (95% CI: 34-92%) and 30% (95% CI: 0-74%), respectively. The pooled prevalence of amphistome species infection in the intermediate host (IH) snails based on detection techniques was higher with PCR compared to the dissection and shedding of cercariae. The results from the quality effects model revealed a high heterogeneity and publication bias between studies. This meta-analysis provided valuable insights into the prevalence and infection rates of amphistome species in snail IHs across different geographical regions.

From wildlife to humans: The global distribution of Trichinella species and genotypes in wildlife and wildlife-associated human trichinellosis.

Zoonotic nematodes of the genus Trichinella are foodborne parasites that have a global distribution in wild carnivores and omnivores, with spillover and spillback into domestic livestock and people, with concomitant trade and health consequences. Historically, most human cases were linked to domestic pigs infected with Trichinella spiralis, but under current high biosecurity swine production in many countries, wildlife have become a more important source of human trichinellosis. The aim of this review is to update the global distribution of Trichinella species and genotypes reported in wildlife, as well as reported human outbreaks from the consumption of wildlife. Using several online databases and by "snowballing" references, hundreds of reports of Trichinella spp. in wildlife published between January 1991 and December 2023 provide an important update to the host and geographic range for each of the recognized 13 species/genotypes, grouped by continent. Surveillance effort was highest in Europe and North America, while Africa, Asia, Oceania, Central and South America have had limited surveillance, in some instances with human cases serving as sentinels of transmission in a region. Dozens of human outbreaks are described, with wild boars (Sus scrofa) being the most frequently implicated wildlife species in human outbreaks globally. Bears are an important source of infection in North America, for wildlife tourism, and importation of bear meat has also been implicated in multicountry outbreaks. The largest study limitation was the dearth of molecular identification of larvae in both wildlife surveillance studies and human outbreaks, particulary in under-studied regions. We highlight the need for enhanced molecular epidemiological approaches to outbreaks of this important foodborne parasite, and emphasize the need for a One Health approach to manage Trichinella spp. which transmit among terrestrial and marine wildlife (including migratory birds), pigs, horses, and people, often across large geographic scales and borders.

Amphistome Infection and Species Diversity of Freshwater Snails Collected from Selected Wildlife Drinking Water Sources in Matebeleland Region of Zimbabwe.

This study aimed at determining the identity of freshwater snails collected from selected water habitats frequented by wildlife as source of drinking water in the Matebeleland region of Zimbabwe and further screening the identified snails for natural infections with amphistomes using PCR. A total of 487 freshwater snails were collected from six areas in the Matebeleland region of Zimbabwe for identification and screening of amphistome infection. Eight freshwater snail species were morphologically identified and Biomphalaria pfeifferi, Bul. tropicus, Bul. truncatus, Bul. globosus, and L. (R.) natalensis were confirmed using the COI gene. Bulinus tropicus and Phy. acuta were the most abundant species at 33.9% (165/487) and 31.2% (155/487), respectively. DNA of amphistome was detected in 11.9% (58/487) of the collected snails. The highest infection rate was detected in Bul. globosus (44.4%). West Nicholson recorded the highest infection rate (33.9%), and infection was not detected in L. (R.) natalensis, Phy. acuta, and Bellamya spp. Amphistome DNA from M. tuberculata was successfully sequenced and identified as Calicophoron microbothrium. An additional band was detected in M. tuberculata, Bul. tropicus, and Bul. trancatus, which showed a 96.42% similarity to Paragonimus sp. sequence in the GenBank.

Prevalence and geographical distribution of amphistomes of African wild ruminants: A scoping review.

This review summarizes published records on the prevalence, species diversity, geographical distribution, mixed infections, co-infections with other trematodes and intermediate hosts (IHs) of amphistomes (rumen flukes) of wild ruminants in Africa. Literature search was conducted on Google Scholar, PubMed and JSTOR, using a combination of predetermined search terms and Boolean operators. Of the 54 African countries searched, results showed that occurrence of amphistome infections in wild ruminants have only been reported in 23 countries. A total of 38 amphistome species consisting of the following 11 genera were recorded, viz Bilatorchis, Calicophoron, Carmyerius, Choerecotyloides, Cotylophoron, Explanatum, Gastrothylax, Gigantocotyle, Leiperocotyle, Paramphistomum and Stephanopharynx. These were recorded in 39 wild ruminant species, belonging to the Bovidae family. The genus Carmyerius recorded the highest number of species (n = 13) across nine countries Africa. However, Calicophoron species (n = 9) were more widely distributed, occurring in 17 countries across all regions of Africa. Species of this genus collectively infected 27 wild ruminant species. However, at a species level, Cotylophoron cotylophorum infected the highest number of wild ruminant species. Prevalence of infection based on post-mortem examination ranged from 1.89% in African Buffalo to 100% in Defassa waterbuck from Egypt and Zambia, respectively. The most common mixed infections recorded were those between amphistomes of the same or different genus. Snail intermediate hosts (IHs) were described for 10/38 amphistome species, and these were predominantly species from Plarnobidae family. Despite the richness in diversity of amphistomes infecting wild ruminants in Africa, there is need to further confirm identity of snail IHs and the amphistome species using both morphological and molecular techniques. Furthermore, more studies are recommended to assess the burden of amphistomosis in commercially reared wildlife/game farming, mixed game and livestock farming systems in Africa.

Molecular and serological prevalence of corridor disease (buffalo associated Theileria parva infection) in cattle populations at the livestock/game interface of KwaZulu-Natal province, South Africa.

Theileria parva are intracellular protozoal parasites responsible for three disease syndromes in cattle, namely East Coast fever (ECF), Corridor disease (CD) and Zimbabwean theileriosis. The increase in reports of CD outbreaks in recent years has raised questions about the probability of adaptation of buffalo-derived T. parva strains in cattle herds adjacent to game reserves. A cross-sectional study was conducted from March 2016 to December 2018 to investigate the extent of occurrence of T. parva infections in cattle in the CD-controlled area of KwaZulu-Natal Province. Blood samples were collected from 1137 cattle from 14 herds and analysed by quantitative real-time PCR (qPCR) and indirect fluorescent antibody test (IFAT) to determine the prevalence of T. parva. A total of 484 samples from 4 of the 14 herds were further tested on qPCR for the presence of T. taurotragi infections. The data were analysed using descriptive statistics and a chi-square test was used to assess association between variables. The overall prevalence of T. parva was 1.3% (95%CI:1-2%) and 19.9% (95%CI:17-22%) on qPCR and IFAT, respectively. The qPCR positive samples were detected in March and May while IFAT positive samples were detected in all seasons sampled, with higher numbers during summer months. The Pearson Chi-squared test showed that T. parva prevalence rates based on both qPCR and IFAT were positively associated with herds with previous history of CD outbreaks (χ2 = 8.594, p = 0.003; χ2 = 69.513, p < 0.001, respectively). The overall prevalence of T. taurotragi was 39.4% (95% CI: 35-44%) with the herd-level prevalence ranging between 35.0% and 43.4%. Possible cross-reaction of T. parva IFAT to T. taurotragi was detected on few samples, however, there was no significant association between T. taurotragi infections and IFAT positivity (χ2 = 0.829, p = 0.363). Results from this study demonstrated the extent of occurrence of subclinical carriers and the level of exposure to T. parva infections in cattle populations at a livestock/game interface area of KwaZulu-Natal Province. The molecular and seroprevalence rates were low when compared with other areas where cattle-adapted T. parva infections are endemic. The adaptation of buffalo-derived T. parva in cattle population resulting in cattle-cattle transmissions seem to be unlikely under the current epidemiological state.

Prevalence of tick-borne pathogens in Rhipicephalus species infesting domestic animals in Africa: A systematic review and meta-analysis.

Rhipicephalus ticks transmit important tick-borne pathogens (TBPs) such as Anaplasma, Babesia, and Theileria spp. which cause major economic losses in livestock production and contribute to emerging zoonotic diseases. A vast amount of data is available based on the demonstration of these pathogens in various host tissues, with limited information on the prevalence of these TBPs and their vectors. Quantifying TBPs infection rates among Rhipicephalus spp. is essential for the effective control and management of TBDs in domestic animals and surveillance of emerging diseases in humans, as they have close social associations. This review summarizes the prevalence of TBPs in Rhipicephalus spp. from domestic animals of Africa. A thorough search was done in SCOPUS, Web of Knowledge, PubMed, Google Scholar, and library sources from 2000 to 2022. All research in Africa reporting TBPs infection rates in Rhipicephalus spp. were included in the selection criteria. The meta-analysis evaluated publication bias using funnel plots to analyze the observed heterogeneity and applied a quality effects model. Prevalence estimates were based on data from 46 studies reporting TBPs infection rates in Rhipicephalus spp. from northern and sub-Saharan Africa. Sub-group analysis was done by geographic region and tick genus. A total of 12,368 Rhipicephalus spp. collected from domestic animals in Africa were used in the meta-analysis. The quality effects model revealed a high degree of heterogeneity among studies on the various TBPs. The overall prevalence of detected TBPs such as Theileria spp. was 8% (95% CI: 3-15%), Rickettsia spp. 3% (95% CI: 0-9%), Ehrlichia spp. 7% (95% CI: 2-14%), Anaplasma spp. 8% (95% CI: 2-16%), Coxiella spp. 10% (95% CI: 1-26%) and Babesia spp. 6% (95% CI: 2-12%). Northern Africa had the highest prevalence of Anaplasma spp. 12% (95% CI: 3-25%) and Theileria spp. 16% (95% CI: 0-42%). Whilst West Africa had the highest prevalence for Ehrlichia spp. 12% (95% CI: 3-24%) and eastern Africa for Rickettsia spp. 8% (95% CI: 4-12%). This is a systematic and quantitative investigation of the various TBPs detected in Rhipicephalus tick vectors from domestic animal hosts in Africa. The findings demonstrate considerable species variation across the African continent and offer preliminary estimates of infection rates for the continent.