Search

Maize is an important cash and food crop grown in Tanzania and other parts of the world. The crop is susceptible to fungal infestation and subsequent mycotoxins contamination that negatively affects human and animal health as well as the socio-economic status of the farmers and respective stakeholders. The study was conducted to determine occurrence of aflatoxigenic fungi (A.flavus and A.parasiticus) on maize stored in warehouses found in Morogoro municipality and Makambako district in Tanzania. A total of 226 maize samples were collected from six wards in the selected study areas then analysed for aflatoxigenic fungal infestation. Potato Dextrose Agar was used for isolation of the fungi which were then identified to species level via observation of morphological characteristics with aid of taxonomic keys. The proportional occurrence of A. parasiticus and A. flavus with respect to areas where samples were collected was presented using descriptive statistics. The result showed that only 15% (34/226) of the collected samples were contaminated with Aspergillus flavus and Aspergillus parasiticus. Among the samples collected, the occurrence of A. flavus was higher than that of A. parasiticus whereby 28 samples were contaminated with A. flavus while 6 samples with A. parasiticus. We found that the methods used in the storage of this major staple food used by majority of Tanzanians makes it vulnerable to infestation and subsequent contamination by aflatoxigenic fungi. We therefore recommend that responsible sectors should implement appropriate intervention strategies designed to reduce occurrence of aflatoxigenic Aspergillus species on stored maize.

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.

This study was conducted in Zanzibar Island aiming to provide baseline data on the abundance and diversity of rodents and shrews in that area, cross-section survey was conducted involving five selected habitats (farm, domestic, peridomestic, forest, and grazing area) in every six districts and Shehia, a total of 100 Sherman live traps were placed per site in 10 lines each with 10 trapping stations, 10m apart in each station and each line for four consecutive nights; traps were daily baited by using a mixture of peanut butter and maize brans. A total of 324 individual rodents and insectivores were captured from five different habitats. Individuals belonging to eight species were captured out of 4200 trap nights. Rodents species and insectivores which were identified and recorded were: Mastomys natalensis, Mus muscularis, Rattus rattus, Rattus norvegicus, Cricetomy gambianus, Crocidura spp, Arvicanthis spp and Lophuromys spp, the overall trap success was ranging from 2.4% to 15%, Mastomy natalensis was the most abundant species, accounting for 82 (25.3 % ) individuals of all the rodents collected in different habitats, this was followed by Rattus rattus comprised of 77(23.8%) of individuals captured, Rattus norvegicus comprised of 72 (22.2%) , Mus muscularis comprised of 63(19.4%), Cricetomy gambianus comprised of 13(4%), Shrew (Crocidura spp) comprised of 12(3.7%), Lophuromys spp comprised of 3(0.9%) and Arvicanthis spp comprised of 2(0.6%) individuals captured respectively. Analysis showed that there was a statistically significant difference (P

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.

Feline leukemia virus (FeLV) subgroups have emerged in infected cats via the mutation or recombination of the env gene of subgroup A FeLV (FeLV-A), the primary virus. We report the isolation and characterization of a novel env gene, TG35-2, and report that the TG35-2 pseudotype can be categorized as a novel FeLV subgroup. The TG35-2 envelope protein displays strong sequence identity to FeLV-A Env, suggesting that selection pressure in cats causes novel FeLV subgroups to emerge.

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.

The Tsushima leopard cat (TLC) Prionailurus bengalensis euptilurus, a subspecies of P. bengalensis, is designated a National Natural Monument of Japan, and lives only on Tsushima Island, Nagasaki Prefecture, Japan. TLCs are threatened by various infectious diseases. Feline leukemia virus (FeLV) causes a serious infectious disease with a poor prognosis in cats. Therefore, the transmission of FeLV from Tsushima domestic cats (TDCs) to TLCs may threaten the TLC population. We investigated the FeLV infection status of both TDCs and TLCs on Tsushima Island by screening blood samples for FeLV p27 antigen and using PCR to amplify the full-length FeLV env gene. The prevalence of FeLV was 6.4% in TDCs and 0% in TLCs. We also demonstrated that the virus can replicate in the cells of TLCs, suggesting its potential cross-species transmission. The viruses in TDCs were classified as genotype I/clade 3, which is prevalent on a nearby island, based on previous studies of FeLV genotypes and FeLV epidemiology. The FeLV viruses identified on Tsushima Island can be further divided into 2 lineages within genotype I/clade 3, which are geographically separated in Kamijima and Shimojima, indicating that FeLV may have been transmitted to Tsushima Island at least twice. Monitoring FeLV infection in the TDC and TLC populations is highly recommended as part of the TLC surveillance and management strategy.

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. IMPORTANCE The domestic cat genome contains many endogenous retroviruses, including ERV-DCs. These ERV-DCs have been acquired through germ cell infections with exogenous retroviruses. Some of these ERV-DCs are still capable of producing infectious virions. Hosts must tightly control these ERVs because replication-competent viruses in the genome pose a risk to the host. Here, we investigated how ERV-DCs are adapted by their hosts. Replication-competent viruses with strong promoter activity, such as ERV-DC10 and ERV-DC18, were suppressed by promoter methylation in LTRs. On the other hand, replication-competent viruses with weak promoter activity, such as ERV-DC14, seemed to escape strict control via promoter methylation by the host. Interestingly, ERV-DCs with weak promoter activity, such as ERV-DC14, have expanded in the cat genome significantly more than ERV-DCs with strong promoter activity. Our results improve the understanding of the host-virus conflict and how ERVs adapt in their hosts over time.

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&ndash, 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&ndash, 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&ndash, 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.