RESUMO
The Middle East respiratory syndrome Coronavirus (MERS-CoV) is one of the human coronaviruses that causes severe respiratory infection. Bats are considered to be the natural reservoir, where dromedary camels (DC) are the intermediate hosts of the virus. The current study was undertaken to provide an update on global distribution of the virus in camels, and to investigate the pooled prevalence and camel-associated risk factors of infection. After registration of the review protocol in the Open Science Framework, data searches were conducted on 18 April 2023 through Embase, PubMed, Scopus, and Web of Science. Considering only natural MERS-CoV infection in camels, 94 articles were selected for data curation through blind screening by two authors. Meta-analysis was conducted to estimate the pooled prevalence and to evaluate camel-associated risk factors. Finally, the results were presented in forest plots. The reviewed articles tested 34 countries, of which camels of 24 countries were seropositive and in 15 countries they were positive by molecular method. Viral RNA was detected in DC. Non-DC, such as bactrian camels, alpaca, llama, and hybrid camels were only seropositive. The global estimated pooled seroprevalence and viral RNA prevalence in DC were 77.53% and 23.63%, respectively, with the highest prevalence in West Asia (86.04% and 32.37% respectively). In addition, 41.08% of non-DC were seropositive. The estimated pooled prevalence of MERS-CoV RNA significantly varied by sample types with the highest in oral (45.01%) and lowest in rectal (8.42%) samples; the estimated pooled prevalence in nasal (23.10%) and milk (21.21%) samples were comparable. The estimated pooled seroprevalence in <2 years, 2-5 years, and > 5 years age groups were 56.32%, 75.31%, and 86.31%, respectively, while viral RNA prevalence was 33.40%, 15.87%, and 13.74%, respectively. Seroprevalence and viral RNA prevalence were generally higher in females (75.28% and 19.70%, respectively) than in males (69.53% and 18.99%, respectively). Local camels had lower estimated pooled seroprevalence (63.34%) and viral RNA prevalence (17.78%) than those of imported camels (89.17% and 29.41%, respectively). The estimated pooled seroprevalence was higher in camels of free-herds (71.70%) than confined herds (47.77%). Furthermore, estimated pooled seroprevalence was higher in samples from livestock markets, followed by abattoirs, quarantine, and farms but viral RNA prevalence was the highest in samples from abattoirs, followed by livestock markets, quarantine, and farms. Risk factors, such as sample type, young age, female sex, imported camels, and camel management must be considered to control and prevent the spread and emergence of MERS-CoV.
RESUMO
This study aimed to estimate the antimicrobial resistance (AMR) patterns and tetracycline-resistant gene profiles of Escherichia coli (E. coli) from broiler meat and livers sourced from live bird markets (LBMs) and supermarkets (SMs) in Chattogram, Bangladesh. In total, 405 samples were collected from SMs and LBMs, comprising muscle (n = 215) and liver (n = 190) samples. Disc diffusion tests were used to determine antimicrobial susceptibility profiles. PCR was used to identify E. coli and tetracycline-resistant genes. Over half (57%) of the chicken product samples were positive for E. coli. The AMR profiling of these isolates showed that the highest prevalence of resistance was against sulphamethoxazole-trimethoprim (89%), followed by tetracycline (87%), ampicillin (83%), and ciprofloxacin (61%). Among the antimicrobials listed by the World Health Organization as critically important, E. coli isolates were found to be resistant to cephalexin (37%), gentamicin (32%), and colistin sulfate (21%). A large proportion of E. coli demonstrated multi-drug resistance (MDR). Most (84%) of the tetracycline-resistant isolates encoded tetA. Of the remaining isolates, 0.5% encoded tetC, 6.0% encoded two genes, and 3.6% of isolates were tetD, which was newly identified by this study in Bangladesh. Broiler products in Bangladesh are frequently contaminated with multi-drug-resistant E. coli, with differential carriage of tetracycline genes. The prevalence of tetracycline resistance among E. coli indicates a concern for poultry health and welfare regarding the management of colibacillosis. It also indicates growing public health risks of AMR among broiler-associated pathogens, which can be transferred to humans via the food chain. Appropriate control measures should be developed and implemented, focused on the rational use of antimicrobials in poultry farming systems, to mitigate risk from this drug-resistant zoonotic pathogen from foods of animal origin and to protect public health.
RESUMO
Antimicrobial resistance (AMR) has become an emerging health issue globally, posing a threat to zoonotic pathogens and foodborne diseases. In Bangladesh, the poultry sector supplies the majority of the demand for animal-source protein. The irrational and excessive use of antimicrobials (AMU) has been observed in the poultry sector. The development of AMR is associated with many factors, including the knowledge and attitudes of poultry farmers. Therefore, AMR reduction requires intervention from all the stockholders, including the farmers who are considered as end users of antimicrobials. This current research conducted a cross-sectional study to assess the knowledge, attitudes, and practices (KAP) of poultry farmers on AMU and AMR in Bangladesh. We determined the KAP of poultry farmers (broiler and layer farmers) of some selected districts of the country using a tested and paper-based questionnaire. The results demonstrated that most of the respondents have insufficient KAP regarding AMU and AMR. The respondents used a variety of antimicrobials primarily in the treatment of various diseases in poultry. One-third of the farmers did not seek antimicrobials from registered vets. Instead, they depended on others or themselves. The factor score analysis further revealed that the farmers' demographic and socioeconomic variables were significant factors influencing the KAP. An adjusted logistic regression analysis showed that older farmers with 9-12 years of farming experience and graduate-level education, engaging in medium-sized layer farming, were more likely to have correct KAP on AMU and AMR. Further, farmers from the Cox's Bazar region showed correct knowledge, whereas farmers of the Chattogram region showed a correct attitude towards AMU and AMR. A Spearman's rank-order correlation revealed a positive association between knowledge-attitudes and knowledge-practices. The findings of the current investigation provide baseline evidence about the KAP of poultry farmers from low-income resources and offer insights into designing interventions and policies for the use of AMU and AMR in Bangladesh.
RESUMO
BACKGROUND: Tumour metastasis to the brain is a common and deadly development in certain cancers; 18-30 % of breast tumours metastasise to the brain. The contribution that gene silencing through epigenetic mechanisms plays in these metastatic tumours is not well understood. RESULTS: We have carried out a bioinformatic screen of genome-wide breast tumour methylation data available at The Cancer Genome Atlas (TCGA) and a broad literature review to identify candidate genes that may contribute to breast to brain metastasis (BBM). This analysis identified 82 candidates. We investigated the methylation status of these genes using Combined Bisulfite and Restriction Analysis (CoBRA) and identified 21 genes frequently methylated in BBM. We have identified three genes, GALNT9, CCDC8 and BNC1, that were frequently methylated (55, 73 and 71 %, respectively) and silenced in BBM and infrequently methylated in primary breast tumours. CCDC8 was commonly methylated in brain metastases and their associated primary tumours whereas GALNT9 and BNC1 were methylated and silenced only in brain metastases, but not in the associated primary breast tumours from individual patients. This suggests differing roles for these genes in the evolution of metastatic tumours; CCDC8 methylation occurs at an early stage of metastatic evolution whereas methylation of GANLT9 and BNC1 occurs at a later stage of tumour evolution. Knockdown of these genes by RNAi resulted in a significant increase in the migratory and invasive potential of breast cancer cell lines. CONCLUSIONS: These findings indicate that GALNT9 (an initiator of O-glycosylation), CCDC8 (a regulator of microtubule dynamics) and BNC1 (a transcription factor with a broad range of targets) may play a role in the progression of primary breast tumours to brain metastases. These genes may be useful as prognostic markers and their products may provide novel therapeutic targets.
