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Large-scale poultry production in low- and middle-income countries may be a source of adulterated products (e.g., Salmonella contamination, antibiotic residues) that can be disseminated over wide areas. We employed a cross-sectional survey of 199 randomly selected poultry farms in Lagos State, Nigeria, to estimate the prevalence of non-typhoidal Salmonella (NTS), and biosecurity and antibiotic use practices. Pooled fecal samples were collected from laying chickens and from poultry handlers. Selective culture, biochemical assays, and PCR (invA) were used to isolate and confirm NTS isolates. NTS was detected at 14% of farms (28/199) and from 10% of farm workers (6/60). Multivariate logistic regression analysis indicated that antiseptic foot dips reduced the odds ratio (OR) for detecting NTS in chicken feces [OR: 0.55; 95% confidence interval (CI) 0.07-0.58]. Most farms (94.5%, 188/199) used antibiotics for treatment and prophylaxis, but no farms (0/199) exercised withdrawal before sale of products. Most farms (86.4%, 172/199) reported using antibiotic cocktails that included medically important colistin, ciprofloxacin, chloramphenicol, and gentamicin. Egg production in Lagos State relies heavily on antibiotics and antibiotic residues are likely passed to consumers through poultry products, but there is evidence that low-cost biosecurity controls are effective for limiting the presence of NTS on farms., (© 2024. The Author(s).)

Five subcluster C1 mycobacteriophages, Blackbrain, Cactojaque, Kboogie, Trinitium, and YoungMoneyMata, were isolated from soil using the host Mycobacterium smegmatis mc 2 155. The genome sizes range from 154,512 to 156,223 bp. The largest genome encodes 237 predicted proteins, 34 tRNAs, and 1 transfer-messenger RNA (tmRNA)., Competing Interests: The authors declare no conflict of interest.

Four lytic mycobacteriophages, namely, SynergyX, Abinghost, Bananafish, and Delton, were isolated from soil in Washington, DC, using the bacterial host Mycobacterium smegmatis mc 2 155. Analysis of the genomes revealed that they belong to two subclusters of actinobacteriophage cluster B (subclusters B2 and B3) and subcluster D1 of cluster D.

The course-based research experience (CRE) with its documented educational benefits is increasingly being implemented in science, technology, engineering, and mathematics education. This article reports on a study that was done over a period of 3 years to explicate the instructional processes involved in teaching an undergraduate CRE. One hundred and two instructors from the established and large multi-institutional SEA-PHAGES program were surveyed for their understanding of the aims and practices of CRE teaching. This was followed by large-scale feedback sessions with the cohort of instructors at the annual SEA Faculty Meeting and subsequently with a small focus group of expert CRE instructors. Using a qualitative content analysis approach, the survey data were analyzed for the aims of inquiry instruction and pedagogical practices used to achieve these goals. The results characterize CRE inquiry teaching as involving three instructional models: 1) being a scientist and generating data; 2) teaching procedural knowledge; and 3) fostering project ownership. Each of these models is explicated and visualized in terms of the specific pedagogical practices and their relationships. The models present a complex picture of the ways in which CRE instruction is conducted on a daily basis and can inform instructors and institutions new to CRE teaching.

Two temperate mycobacteriophages, Dallas and Jonghyun, were isolated from soil in Washington, DC, using the bacterial host Mycobacterium smegmatis mc 2 155. Analysis of the genomes revealed that Dallas and Jonghyun belong to clusters J and G, respectively. The structures of the genomes are typical of their respective clusters.

Background: Awareness of various aspects of Diabetes Mellitus (DM) is essential for the prevention, management and control of the disease. However, several studies have consistently shown that awareness of DM in the general population is low. None of these studies, however, was conducted in The Gambia, even though the condition constitutes a major public health problem in the country. In this paper, we assessed the awareness of DM among diabetic patients attending the Medical Out-Patient Department (MOPD) of Royal Victoria Teaching Hospital (RVTH), Banjul., Methods: We interviewed 200 patients attending the MOPD of RVTH. We used a tool containing questions on patient's demographic characteristics and awareness of various aspects of DM including general knowledge on DM, causes, complications, management and prevention., Results: Of the 199 patients who were aware of their condition, only 47% said they knew what DM is. Similarly, 53% of the study participants had no knowledge of the causes of DM and about 50% were not aware of the methods of prevention. 67% knew that DM can result to loss of sight while 46.5% knew that DM can cause poor wound healing. Few respondents knew that DM can lead to kidney failure (13.5%), skin sepsis (12.0%), heart failure (5.5%) and stroke (4.5%). Close to 50% of the respondent did not know how DM can be prevented. Level of education, duration of illness and knowledge of a family member with diabetes were important predictors of knowledge in our study., Conclusion: Our study shows that the majority of patients attending the MOPD have poor knowledge on several aspects of DM. Hence, there is need for conscious efforts towards improving the level of awareness through health education and promotion, not limited to the hospital but also within the general population, as part of strategies to prevent, manage and control DM.

Blood flukes or schistosomes are the causative agents of human schistosomiasis, one of the major neglected tropical diseases. Draft genome sequences have been reported for schistosomes, but functional genomics tools are needed to investigate the role and essentiality of the newly reported genes. Vector based RNA interference can contribute to functional genomics analysis for schistosomes. Using mRNA encoding reporter firefly luciferase as a model target, we compared the performance of a schistosome and a human promoter from the U6 gene in driving shRNA in human fibrosarcoma cells and in cultured schistosomes. Further, both a retroviral [Murine leukemia virus (MLV)] and plasmid (piggyBac, pXL-Bac II) vector were utilized. The schistosome U6 gene promoter was 270 bp in length, the human U6 gene promoter was 264 bp; they shared 41% identity. Following transduction of both HT1080 fibrosarcoma cells and schistosomules of Schistosoma mansoni with pseudotyped MLV virions, stronger knockdown of luciferase activity was seen with the virions encoding the human U6 promoter driven shRNA than the schistosome U6 promoter. A similar trend was seen after transfection of HT1080 cells and schistosomules with the pXL-Bac-II constructs-stronger knockdown of luciferase activity was seen with constructs encoding the human compared to schistosome U6 promoter. The findings indicate that a human U6 gene promoter drives stronger shRNA activity than its schistosome orthologue, not only in a human cancer cell line but also in larval schistosomes. This RNA polymerase III promoter represents a potentially valuable component for vector based RNA interference studies in schistosomes and related platyhelminth parasites.

Background: Minimal information on the genome and proteome of Schistosoma haematobium is available, in marked contrast to the situation with the other major species of human schistosomes for which draft genome sequences have been reported. Accordingly, little is known about functional genomics in S. haematobium, including the utility or not of RNA interference techniques that, if available, promise to guide development of new interventions for schistosomiasis haematobia., Methods/findings: Here we isolated and cultured developmental stages of S. haematobium, derived from experimentally infected hamsters. Targeting different developmental stages, we investigated the utility of soaking and/or square wave electroporation in order to transfect S. haematobium with nucleic acid reporters including Cy3-labeled small RNAs, messenger RNA encoding firefly luciferase, and short interfering RNAs (siRNAs). Three hours after incubation of S. haematobium eggs in 50 ng/µl Cy3-labeled siRNA, fluorescent foci were evident indicating that labeled siRNA had penetrated into miracidia developing within the egg shell. Firefly luciferase activity was detected three hours after square wave electroporation of the schistosome eggs and adult worms in 150 ng/µl of mRNA. RNA interference knockdown (silencing) of reporter luciferase activity was seen following the introduction of dsRNA specific for luciferase mRNA in eggs, schistosomules and mixed sex adults. Moreover, introduction of an endogenous gene-specific siRNA into adult schistosomes silenced transcription of tetraspanin 2 (Sh-tsp-2), the apparent orthologue of the Schistosoma mansoni gene Sm-tsp-2 which encodes the surface localized structural and signaling protein Sm-TSP-2. Together, knockdown of reporter luciferase and Sh-tsp-2 indicated the presence of an intact RNAi pathway in S. haematobium. Also, we employed laser scanning confocal microscopy to view the adult stages of S. haematobium., Conclusions: These findings and approaches should facilitate analysis of gene function in S. haematobium, which in turn could facilitate the characterization of prospective intervention targets for this neglected tropical disease pathogen.

RNA interference (RNAi) mediated by short hairpin-RNA (shRNA) expressing plasmids can induce specific and long-term knockdown of specific mRNAs in eukaryotic cells. To develop a vector-based RNAi model for Schistosoma mansoni, the schistosome U6 gene promoter was employed to drive expression of shRNA targeting reporter firefly luciferase. An upstream region of a U6 gene predicted to contain the promoter was amplified from genomic DNA of S. mansoni. A shRNA construct driven by the predicted U6 promoter targeting luciferase was assembled and cloned into plasmid pXL-Bac II, the construct termed pXL-BacII_SmU6-shLuc. Luciferase expression in transgenic fibrosarcoma HT-1080 cells was significantly reduced 96 h following transduction with plasmid pXL-BacII_SmU6-shLuc, which encodes luciferase mRNA-specific shRNA. In a similar fashion, schistosomules of S. mansoni were transformed with the SmU6-shLuc or control constructs. Firefly luciferase mRNA was introduced into transformed schistosomules after which luciferase activity was analyzed. Significantly less activity was present in schistosomules transfected with pXL-BacII_SmU6-shLuc compared with controls. The findings revealed that the putative S. mansoni U6 gene promoter of 270 bp in length was active in human cells and schistosomes. Given that the U6 gene promoter drove expression of shRNA from an episome, the findings also indicate the potential of this putative RNA polymerase III dependent promoter as a component regulatory element in vector-based RNAi for functional genomics of schistosomes., (Copyright © 2011 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.)

The objectives of the study were to determine by the use of a structured questionnaire the prevalence of malaria and its associated symptoms amongst school children and to relate these to the prevalence of malaria determined by microscopic examination. The questionnaire was administered to 840 pupils of classes 3, 5 and 7 (age range 5-16 years) in 17 primary schools of the Kumba Health District of Cameroon. Blood samples were collected from the same individuals for identification of malaria parasites. The prevalence rate by microscopic examination was 41.4% significantly higher (P<0.001) than 23.9% obtained by questionnaire survey. Headache and fever had similar prevalence rates (53.6% and 53.0% respectively) which were significantly higher (P<0.001) than the prevalence rate of malaria by microscopic examination. Other malaria hyphen;related symptoms gave rates which greatly underestimated the prevalence of malaria (P<0.001). There was no significant correlation between the prevalence rates obtained by questionnaire and the rate of malaria by microscopy. The sensitivity and specificity of these screening tests for malaria were all low. The use of the microscope as a malaria diagnostic tool at primary health care unit is strongly recommended.

Objective: To assess the prevalence and intensity of urinary schistosomiasis in school pupils aged five to sixteen years., Setting: Barombi Kotto Health Area, southwest Cameroon., Design: A cross-sectional study., Subjects: Three hundred and forty seven primary school children., Intervention: All children found to be infected were treated with praziquantel (biltricide)., Main Outcome Measures: The study would be able to provide baseline information on the epidemiology of schistosomiasis which is vital for control strategies., Results: The overall prevalence of Schistosoma haematobium in the study areas was 53.6%, with the highest prevalence of 73.9% recorded in Barombi Kotto village. Children resident on Barombi Kotto island were more significantly infected than those on the peripheral mainland (93.3% versus 46.2%, p < 0.01). Prevalence rate and intensity of infection did not vary significantly (p > 0.05) with sex, class or age of the pupils. The mean egg count varied significantly between schools (p < 0.001)., Conclusion: Barombi Kotto village was identified as the focus of urinary schistosomiasis, with the highest recorded in children dwelling on the island, the surrounding lake being the main focus of transmission. Focal snail control as an adjunct of chemotherapy and intensive health education for the local population are strongly recommended as a means of reducing the high infection rate in the area.

Biomedical studies accompanied by a questionnaire survey were carried out on 803 pupils of classes 3, 5 an 7 attending 17 primary schools in the Kumba Health District to determine the prevalence of soil - transmitted nematodes and infection-associated morbidity. The prevalence rate of worms in the sample population from the questionnaire survey was 42.3% which correlates closely with 44.2% recorded for abdominal pains. The biomedical studies gave a worm infection rate of 67.1%. Ascaris lumbricoides, Trichuris trichiura and hookworm had prevalence rates of 54.9%, 33.8% and 20.3% respectively. Mixed infections were recorded in 34.4 % of the sample population compared to 32.8% for single infections. Hookworm infection rate was significantly higher in the rural areas than in the urban areas (27.5 % versus 14.8%, P < 0.001). A similar trend was observed for T. trichiura (38.4% versus 30.3 %, P < 0.02). Prevalence of A. lumbricoides was similar in the urban and rural areas (56.5% versus 52.6%). Males carried heavier burdens of Ascaris and Trichuris than females. The worm burden for all 3 species decreased as children moved to higher classes and with age after the first decade of life. There was a significant correlation between the intensities of infection of A. lumbricoides and T. trichiura.

Studies were carried out on 855 pupils of classes 3, 5 and 7 (age range 5-16 years) attending 17 primary schools in the Kumba Health District, Cameroon, to determine the infection pattern of Schistosoma haematobium in its different communities. The results reveal prevalence rates of 9.7 % for urinary schistosomiasis and 11.6 % for haemuturia. The focal area for Schistosomiasis was Barombi kotto with a prevalence rate of 75.9 %, a finding not significantly different from 78.2 % for haematuria. Low prevalence rates were recorded in the villages at the periphery of Barombi Kotto and also in the vicinity of Kumba town. Lake Barombi Kotto and "Kumba Water" were the main sources of infection in these areas. No significant differences in prevalence were observed between males and females or between children in the different classes surveyed. Age-specific evaluation revealed that peak infection was attained at