Seropositivity of Leptospira in rodents, shrews, and domestic animals in Unguja, Tanzania

Background: Leptospirosis is one of the most commonly neglected zoonoses in developing nations including Tanzania. This study aims to find out the seroprevalence of leptospirosis in rodents, shrews, and domestic animals in different regions in Unguja Island, Tanzania.  Methods: A cross-sectional study was carried out from January to April 2022. The blood samples were collected from rodents and shrews (n=248), cattle (n=247), goats (n=130), sheep (n=32), and dogs (n=80). The blood samples were allowed to clot in a slanted position and serum samples were harvested. A microscopic agglutination test (MAT) was performed on the sera to check for leptospiral antibodies using five Leptospira serovars as antigens (Sokoine, Lora, Pomona, Grippotyphosa and Hebdomadis). Results: The overall seropositivity of leptospiral antibodies was 9.68% in rodents and shrews, 14.57% in cattle, 10.01% in goats, 31.25% in sheep, and 26.25% in dogs. The seropositivity of Leptospira varied significantly with animal species (OR=1.9, 95 % CI:1.1-3.3, p=0.03). The most frequently detected serovar was Sokoine (27.89%), followed by Pomona (19.47%), Lora (18.26%), Grippotyphosa (17.98%), and Hebdomadis (8.16%), respectively. Conclusion: Our study suggests that further research should be conducted to find out factors of high seropositivity of leptospiral in Unguja. Vaccination of domestic animals with vaccines against local Leptospira strains should be encouraged, and rodent control and public awareness should be emphasized

Determination of bacterial load and antibiotic susceptibility testing of bacteria isolated from students’ toilets at Sokoine University of Agriculture, Morogoro, Tanzania

The circulation of infectious diseases in the community settings in urban and rural areas remains to be a hectic problem. One of the sources of microbial diseases is toilets. This study aimed at isolating, identifying and establishing bacterial loads associated with public restrooms in students’ hostels at Sokoine University of Agriculture in Morogoro, Tanzania. Samples were collected from a total of thirty toilets (60 samples) in different surfaces; (i) surfaces associated with toilets (toilet seats and toilet bowls), (ii) surfaces routinely touched with hands (door handles in and out of the restrooms, faucet handles and toilet flush handles) and (iii) the restroom floors. Samples were inoculated in MacConkey and Blood agar and then incubated at 37oC for 24 hours. All isolates were sub cultured and identified based on macro- and micro-morphology and Standard Biochemical Tests. The establishment of total bacteria load was done using Standard Plate Count Method. The sensitivity testing of the isolates were carried out using the Disk Diffusion Method on nutrient agar plate. The following bacteria genera and species were isolated from the students’ toilets; Staphylococcus aureus (25.0%), Escherichia coli (36.7%), Pseudomonas aeruginosa (13.3%), Streptococcus pyogenes (6.7%), Proteus mirabilis (6.7%) and Klebsiella pneumonia (11.6%). The results from total bacterial count indicated that the surfaces routinely touched with hands had highest bacteria load compared to restroom floor and toilet seats. However, the differences of means among the surfaces were not statistically significant (P= 0.6762).  Sensitivity testing of the isolates against commonly used antibiotics in the study area showed that all bacterial isolates tested were resistant and intermediate resistant to at least one antibiotic. Keywords: Pathogenic bacteria, Students’ hostels, bacteria count, antibiotic susceptibility testing

Transcriptional Regulation of Infectious Feline ERVs

Endogenous retroviruses (ERVs) are the remnants of ancient retroviral infections of germ cells. Previous work identified one of the youngest feline ERV groups, ERV-DC, and reported that two ERV-DC loci, ERV-DC10 and ERV-DC18 (ERV-DC10/DC18), can replicate in cultured cells. Here, we identified another replication-competent provirus, ERV-DC14, on chromosome C1q32. ERV-DC14 differs from ERV-DC10/DC18 in its phylogeny, receptor usage, and, most notably, transcriptional activities; although ERV-DC14 can replicate in cultured cells, it cannot establish a persistent infection owing to its low transcriptional activity. Furthermore, we examined ERV-DC transcription and its regulation in feline tissues. Quantitative reverse transcription-PCR (RT-PCR) detected extremely low ERV-DC10 expression levels in feline tissues, and bisulfite sequencing showed that 5′ long terminal repeats (LTRs) of ERV-DC10/DC18 are significantly hypermethylated in feline blood cells. Reporter assays found that the 5′-LTR promoter activities of ERV-DC10/DC18 are high, whereas that of ERV-DC14 is low. This difference in promoter activity is due to a single substitution from A to T in the LTR, and reverse mutation at this nucleotide in ERV-DC14 enhanced its replication and enabled it to persistently infect cultured cells. Therefore, ERV-DC LTRs can be divided into two types based on this nucleotide, the A type or T type, which have strong or attenuated promoter activity, respectively. Notably, ERV-DCs with T-type LTRs, such as ERV-DC14, have expanded in the cat genome significantly more than A-type ERV-DCs, despite their low promoter activities. Our results provide insights into how the host controls potentially infectious ERVs and, conversely, how ERVs adapt to and invade the host genome

Prevalence and related risk factors of porcine cysticercosis and African swine fever in selected urban/peri-urban areas of Morogoro, Tanzania

This study was carried out to estimate the prevalence and related risk factors of porcine cysticercosis (caused by Taenia solium) and African swine fever (ASF) in domestic pigs, and assesses the state of pork inspection in urban/peri-urban areas of Morogoro region, Tanzania, between November 2010 and January 2011. A two stage random sampling was employed. A total of 260 live pigs were tested serologically. Serum samples were tested for the presence of circulating parasite antigen using a monoclonal antibody-based sandwich enzyme-linked immunosorbent assay (Ag-ELISA) and indirect ELISA (Ab- ELISA) for porcine cysticercosis and ASF, respectively. In addition, a questionnaire survey to collect information on pig production, occurrence and awareness of porcine cysticercosis and African swine fever, risk factors for both diseases was conducted in the selected households from which pigs were sampled. A total of 18 pork traders were also interviewed to collect information on the status of pork inspection. Four pigs (1.54%: 95%CI=0.04–3.1) were found positive by the Ag-ELISA with no statistical significant differences by age group (P=0.57), while ASF antibody titre detection revealed no specific ASF antibody response in all 260 pigs. This study recommends further extensive surveillance aiming at monitoring porcine cysticercosis dynamics in urban/peri-urban pig farming so that more baseline information can be available not only for research purposes but even for design and implementation of long term control strategies. It is recommended that surveillance and control of ASF outbreak in future should focus on the active monitoring, early detection and effective quarantine measures at the point of ASF occurrence

Identification of Felis catus Gammaherpesvirus 1 in Tsushima Leopard Cats (Prionailurus bengalensis euptilurus) on Tsushima Island, Japan

Felis catus gammaherpesvirus 1 (FcaGHV1) is a widely endemic infection of domestic cats. Current epidemiological data identify domestic cats as the sole natural host for FcaGHV1. The Tsushima leopard cat (TLC; Prionailurus bengalensis euptilurus) is a critically endangered species that lives only on Tsushima Island, Nagasaki, Japan. Nested PCR was used to test the blood or spleen of 89 TLCs for FcaGHV1 DNA; three (3.37%; 95% CI, 0.70–9.54) were positive. For TLC management purposes, we also screened domestic cats and the virus was detected in 13.02% (95% CI, 8.83–18.27) of 215 cats. Regarding phylogeny, the partial sequences of FcaGHV1 from domestic cats and TLCs formed one cluster, indicating that similar strains circulate in both populations. In domestic cats, we found no significant difference in FcaGHV1 detection in feline immunodeficiency virus-infected (p = 0.080) or feline leukemia virus-infected (p = 0.163) cats, but males were significantly more likely to be FcaGHV1 positive (odds ratio, 5.86; 95% CI, 2.27–15.14) than females. The higher frequency of FcaGHV1 detection in domestic cats than TLCs, and the location of the viral DNA sequences from both cats within the same genetic cluster suggests that virus transmission from domestic cats to TLCs is likely

Assessment of the Knowledge and Awareness of Leptospirosis among Households, Farmers, and Livestock Keepers in Unguja Island, Tanzania: A Cross-Sectional Study

Limited understanding exists concerning leptospirosis in Zanzibar. The objective of this study is to evaluate the degree of knowledge and awareness of leptospirosis within the urban and peri-urban populations of Unguja. A cross-sectional study was conducted utilizing semi-structured questionnaires from January to April 2022. Two hundred respondents were randomly selected (130 males and 70 females) aged between 18 and 89 years. Descriptive analysis was employed to assess the main trends in knowledge and awareness, and χ2 analysis was utilized to determine associations between demographic characteristics with respondents' knowledge and awareness. The majority of respondents (64%) lacked awareness of leptospirosis' etiology, but a significant proportion of respondents had a favorable attitude (68.6%) towards leptospirosis compared to their average knowledge and awareness (35%) and practices (29.3%). Nonetheless, the livestock keeper, farmers, fishermen, and healthcare providers had low levels of knowledge and awareness. The findings also demonstrated that males had a strong association with occupational physical activities, while educational level was associated with preventive practices. Living in urban or peri-urban areas was significantly linked with the respondents' practices. The study's outcomes demonstrated low levels of community knowledge and awareness regarding leptospirosis' etiology, mode of transmission, and symptoms among livestock keepers, farmers, fishermen, and healthcare providers. Although most respondents had a favorable attitude, their low level of knowledge and poor practices indicate that supplementing a positive attitude with enhanced knowledge and awareness is necessary to promote individual engagement in preventive measures

Reduced Folate Carrier: an Entry Receptor for a Novel Feline Leukemia Virus Variant.

Feline leukemia virus (FeLV) is horizontally transmitted among cats and causes a variety of hematopoietic disorders. Five subgroups of FeLV, A to D and T, each with distinct receptor usages, have been described. Recently, we identified a new FeLV Env (TG35-2) gene from a pseudotyped virus that does not belong to any known subgroup. FeLV-A is the primary virus from which other subgroups have emerged via mutation or recombination of the subgroup A env gene. Retrovirus entry into cells is mediated by the interaction of envelope protein (Env) with specific cell surface receptors. Here, phenotypic screening of a human/hamster radiation hybrid panel identified SLC19A1, a feline reduced folate carrier (RFC) and potential receptor for TG35-2-phenotypic virus. RFC is a multipass transmembrane protein. Feline and human RFC cDNAs conferred susceptibility to TG35-2-pseudotyped virus when introduced into nonpermissive cells but did not render these cells permissive to other FeLV subgroups or feline endogenous retrovirus. Moreover, human cells with genomic deletion of RFC were nonpermissive for TG35-2-pseudotyped virus infection, but the introduction of feline and human cDNAs rendered them permissive. Mutation analysis of FeLV Env demonstrated that amino acid substitutions within variable region A altered the specificity of the Env-receptor interaction. We isolated and reconstructed the full-length infectious TG35-2-phenotypic provirus from a naturally FeLV-infected cat, from which the FeLV Env (TG35-2) gene was previously isolated, and compared the replication of the virus in hematopoietic cell lines with that of FeLV-A 61E by measuring the viral RNA copy numbers. These results provide a tool for further investigation of FeLV infectious disease.IMPORTANCE Feline leukemia virus (FeLV) is a member of the genus Gammaretrovirus, which causes malignant diseases in cats. The most prevalent FeLV among cats is FeLV subgroup A (FeLV-A), and specific binding of FeLV-A Env to its viral receptor, thiamine transporter feTHTR1, is the first step of infection. In infected cats, novel variants of FeLV with altered receptor specificity for viral entry have emerged by mutation or recombination of the env gene. A novel FeLV variant arose from a subtle mutation of FeLV-A Env, which altered the specific interaction of the virus with its receptor. RFC, a folate transporter, is a potential receptor for the novel FeLV variant. The perturbation of specific retrovirus-receptor interactions under selective pressure by the host results in the emergence of novel viruses