Thermophilic Campylobacter species are among the major etiologies of bacterial enteritis globally. This study aimed at assessing the antimicrobial resistance (AMR) profiles, virulence genes, and genetic diversity of thermophilic Campylobacter species isolated from a layer poultry farm in South Korea. One hundred fifty-three chicken feces were collected from two layer poultry farms in Gangneung, South Korea. The Campylobacter species were isolated by cultural techniques, while PCR and sequencing were used for species confirmation. Antimicrobial susceptibility testing for six antimicrobials [ciprofloxacin (CIP), nalidixic acid (NAL), sitafloxacin (SIT), erythromycin (ERY), tetracycline (TET), and gentamicin (GEN)] was carried out by broth microdilution. Three AMR and nine virulence genes were screened by PCR. Genotyping was performed by flaA-restriction fragment length polymorphism (RFLP) and multilocus sequence typing (MLST). Of the 153 samples, Campylobacter spp. were detected in 55 (35.9%), with Campylobacter jejuni and Campylobacter coli being 49 (89.1%) and six (10.9%), respectively. High-level resistance was observed for CIP (100%), NAL (100%), and TET (C. jejuni, 93.9%; C. coli: 83.3%). No resistance was observed for SIT. The missense mutation (C257T) in gyrA gene was confirmed by sequencing, while the tet(O) gene was similar to known sequences in GenBank. The rate of multidrug-resistant (MDR) strains was 8.2%, and they all belonged to C. jejuni. All Campylobacter isolates possessed five virulence genes (cdtB, cstII, flaA, cadF, and dnaJ), but none possessed ggt, while the rates for other genes (csrA, ciaB, and pldA) ranged between 33.3 and 95.9%. The flaA-RFLP yielded 26 flaA types (C. jejuni: 21 and C. coli: five), while the MLST showed 10 sequence types (STs) for C. jejuni and three STs for C. coli, with CC-607 (STs 3611) and CC-460 (ST-460) being predominant. Among the 10 STs of C. jejuni, three were newly assigned. The findings of this study highlight the increased resistance to quinolones and TET, the virulence potential, and the diverse genotypes among Campylobacter strains isolated from the layer poultry farm.
Background: A growing number of Campylobacter species other than C. jejuni and C. coli have been considered as emerging human and animal pathogens. However, the contribution of these species to human gastroenteritis is poorly documented. This study aimed at detecting Campylobacter species from human and cattle faecal samples in Kilosa district, Tanzania using Polymerase Chain Reaction (PCR) amplification of the 16S rRNA gene, and Sanger sequencing . Methods: A total number of 100 faecal samples (70 from human and 30 from cattle) were collected from diarrheic and non-diarrheic patients and healthy cattle in Kilosa district, Tanzania from July to October 2019. Species identification was conducted by PCR and 16S rRNA sequencing. The phylogenetic analysis was carried out by comparison of the 16S rRNA gene sequences to reference strains by the Neighbor-Joining method in MEGA X. Results: Campylobacter species detection rate by PCR was 65.7% (46/70) and 20% (6/30) in humans and cattle, respectively. There were five human diarrheic cases, four showed Campylobacter presence and two were from children ≤15 years of age. In humans, the 16S rRNA sequencing revealed that C. concisus was the most predominant species occurring at a frequency of 37.8% (14/37), followed by uncultured Campylobacter spp. 24.3% (9/37) and C. hominis 21.6% (8/37). The least represented species were C. jejuni and C. lanienae all occurring at 2.7% (1/37). In cattle, five (100%) sequenced PCR products matched with C. lanienae . Phylogenetic analysis revealed that Campylobacter 16S rRNA sequences were closely related to C. concisus , uncultured Campylobacter sp., C. hominis , and C. gracilis . Conclusion: The non- C. jejuni / C. coli species are present in human and cattle faecal samples and their true occurrence is probably under-reported due to shortcomings of conventional techniques used in most diagnostic microbiology laboratories. Based on our findings, we recommend that molecular techniques be adopted for direct detection of Campylobacter species during routine laboratory screening and surveillance studies. Keywords: Campylobacter , molecular diagnostics, polymerase chain reaction, sequencing, gastroenteritis, Tanzania
A growing number of Campylobacter species other than C. jejuni and C. coli have been considered as emerging human and animal pathogens but their contribution to human gastroenteritis is poorly documented. This study aimed at detecting Campylobacter species from human and cattle faecal samples in Kilosa District, Tanzania using molecular techniques without culture. Seventy (70) faecal samples were collected from five diarrheic and 65 non-diarrheic human patients attending Kilosa District Hospital in Tanzania from July to October 2019. During the same period, 30 faecal samples were also collected from healthy cattle in the same district. Genus and species identification of Campylobacter was conducted on the samples using molecular techniques [the polymerase chain reaction (PCR) and 16S rRNA sequencing]. Phylogenetic analysis was carried out by comparison of the 16S rRNA gene sequences to reference strains by the Neighbor-Joining method in MEGA X. Campylobacter species detection rate by PCR was 65.7% (46/70) and 20% (6/30) in humans and cattle, respectively. There were five human diarrheic cases, four of which were positive for Campylobacter and of these, two were children ≤15 years of age. In humans, 16S rRNA sequencing revealed that C. concisus was the most predominant species occurring at a frequency of 37.8% (14/37), followed by uncultured Campylobacter spp. 24.3% (9/37) and C. hominis 21.6% (8/37). The least represented species were C. jejuni and C. lanienae, all occurring at 2.7% (1/37). In cattle, five (100%) sequenced PCR products matched with C. lanienae. Phylogenetic analysis revealed that with the exception of C. lanienae, 16S rRNA sequences of Campylobacter species were closely related to the reference strains used (Percent identity: 90.51-96.56%). Based on our findings, we recommend that molecular techniques, mainly PCR be adopted for the direct detection of Campylobacter species during laboratory screening and surveillance studies.
The effects of Concept Mapping (CM) and Cooperative Mastery Learning (CML) strategies on students' attitudes towards biology were investigated in this study to instill a positive attitude in students toward biology. The study adopted a quasi-experimental, non-equivalent control group design with pre-and post-tests. A total of 449 senior secondary students (SS2) from Nyamagabe District, Rwanda was studied. Pre- and post-administration of biology Attitude Questionnaire (BAQ) with the reliability (α= 0.95) was used to obtain data. Mean, standard deviation, analysis of covariance, and Bonferroni test were applied for data analysis. The findings showed that students exposed to the CM and CLM strategies have a significantly higher attitude towards biology than those taught using conventional teaching methods (CTM) (F (2, 445) =26.717, p=.000<.05). There was no significant difference in mean attitude scores between male and female students who were taught biology using CM (F (1,148) =.635, p=.427>0.05) and CML (F (1,141) =. 670, p=.796>0.05). Also, the results showed no significant interaction effect of treatment and gender on the attitude of students towards biology (F (2,442) =.586, p=.557>0.05). The study concluded that the CM and CML are effective teaching strategies in raising students’ attitudes towards biology regardless of gender. It is recommended among other things that biology teachers should adopt the CM and CML strategies during instruction to help students develop a positive attitude toward biology.
The emergence of the SARS-CoV-2 Delta variant of concern (lineage B.1.617.2) in late 2020 resulted in a new wave of infections in many countries across the world, where it often became the dominant lineage in a relatively short amount of time. We here report on a novel genomic surveillance effort in Rwanda in the time period from June to September 2021, leading to 201 SARS-CoV-2 genomes being generated, the majority of which were identified as the Delta variant of concern. We show that in Rwanda, the Delta variant almost completely replaced the previously dominant A.23.1 and B.1.351 (Beta) lineages in a matter of weeks, and led to a tripling of the total number of COVID-19 infections and COVID-19-related fatalities over the course of only three months. We estimate that Delta in Rwanda had an average growth rate advantage of 0.034 (95% CI 0.025-0.045) per day over A.23.1, and of 0.022 (95% CI 0.012-0.032) over B.1.351. Phylogenetic analysis reveals the presence of at least seven local Delta transmission clusters, with two of these clusters occurring close to the border with the Democratic Republic of the Congo, and another cluster close to the border with Tanzania. A smaller Delta cluster of infections also appeared close to the border with Uganda, illustrating the importance of monitoring cross-border traffic to limit the spread between Rwanda and its neighboring countries. We discuss our findings against a background of increased vaccination efforts in Rwanda, and also discuss a number of breakthrough infections identified during our study. Concluding, our study has added an important collection of data to the available genomes for the Eastern Africa region, with the number of Delta infections close to the border with neighboring countries highlighting the need to further strengthen genomic surveillance in the region to obtain a better understanding of the impact of border crossings on lowering the epidemic curve in Rwanda.
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