AIM: The objective of this study was to determine the pathogenicity of Salmonella enterica subspecies enterica serovar Enteritidis (SE) phage type (PT) 1 in one-day-old specific pathogen-free (SPF) chicks.
METHODS: Seventy, one-day-old SPF chicks, were divided into SE group (30 chicks), mortality group (10 chicks), both orally inoculated (1.0 ml) with SE PT1 (1 × 108 colony-forming unit per 1.0 ml), and one control group (30 chicks). The chicks were sacrificed at 6 and 12 hours, and days 1, 2, 3, 5, 7, 10, 14, and 21 post-inoculation (pi). Samples were collected for bacterial isolation, histological examination, and ultrastructural examination.
RESULTS: Starting from day 2 pi, the body weight in the SE group significantly (p < 0.05) decreased. The SE isolation percentages from the liver, spleen, mid-intestinal content, cecal content, cecal tonsil, blood, and cloacal swab were 0.73, 0.77, 0.33, 0.33, 0.36, 0.40, and 0.30, respectively. The isolation percentage in the liver was significantly (p < 0.05) higher than the blood and cloacal swab. The villi heights and crypt depths in the SE group were significantly (p < 0.05) greater and smaller, respectively. Ultrastructurally, erosion and necrosis were observed in the microvilli of the cecal tonsil. The bacteria were engulfed by macrophages at the interepithelial clefts of the M-like M cells.
CONCLUSION: It was concluded that the inoculation of SE PT 1 in one-day-old chicks caused a systemic infection with diarrhea, a decrease in the body weight and villi height in the duodenum, jejunum, and ileum, and high bacterial loading in the liver with mild gross and histological lesions of organs, erosion, and necrosis of microvilli and low mortality. The bacteria entered the body system from the intestinal tract through the interepithelial clefts of the M-like M cells of the cecal tonsil.
METHODS: The full genomic sequences of all known different RV-A and -B prototypes were downloaded from the National Centre for Biotechnology Information (NCBI) and divided into minor low-density lipoprotein receptor (LDLR) and major intercellular adhesion molecule groups (ICAM). The sequences were edited using Biological Sequence Alignment Editor, v 7.2.0 (BioEdit software) to study each capsid protein (VP1, VP2, VP3, and VP4) and analyzed using the EMBL-EBI ClustalW server and the more current Clustal Omega tool for the calculation of the identities and similarities.
RESULTS: We analyzed and predicted immunogenic motifs from capsid proteins that are conserved across distinct RV serotypes using a bioinformatics technique. The amino acid sequences of VP3 were found to be the most varied, while VP4 was the most conserved protein among all RV-A and RV-B strains. Among all strains studied, RV-74 demonstrated the highest degree of homology to other strains and could be a potential genetic source for recombinant protein production. Nine highly conserved regions with a minimum length of 9-mers were identified, which could serve as potential immune targets against rhinoviruses.
CONCLUSION: Therefore, bioinformatics analysis conducted in the current study has paved the way for the selection of immunogenic targets. Bioinformatically, the ideal strain's capsid protein is suggested to contain the most common RVs immunogenic sites.
METHOD: Information from 2469 notifying health units in Mexican municipalities was used for this cross-sectional analysis. Multiple logistic regression with interaction effects was chosen as the final model and sensitivity analysis was done to assess potential exposure misclassification of pregnancy status.
RESULTS: Pregnant women were found to have higher odds of severe dengue [1.50 (95% CI 1.41, 1.59)]. The odds of dengue severity varied for pregnant women with DENV-1 [1.45, (95% CI 1.21, 1.74)], DENV-2 [1.33, (95% CI 1.18, 1.53)] and DENV-4 [3.78, (95% CI 1.14, 12.59)]. While the odds of severe dengue were generally higher for pregnant women compared with non-pregnant women with DENV-1 and DENV-2, the odds of disease severity were much higher for those infected with the DENV-4 serotype.
CONCLUSION: The effect of pregnancy on severe dengue is moderated by the dengue serotype. Future studies on genetic diversification may potentially elucidate this serotype-specific effect among pregnant women in Mexico.
METHODS: From 2014 to 2017, a total of 245 invasive S. pneumoniae isolates from children ≤5 years of age were received from hospitals all around Malaysia. All isolates were identified and subjected to serotyping and antimicrobial susceptibility testing.
RESULTS: Of the 245 isolates, 117 (48.0%) were from children aged <1year, 46 (19.05%) were from children aged 1-2 years, and 82 (33.0%) were from children aged 2-5 years. The most common serotypes were 14 (26.9%), 6B (19.6%), 19A (11.8%), 6A (10.6%), and 19F (6.9%) and vaccine coverage was 88.2% for PCV13, 64.1% for PCV10, and 63.3% for PCV7. Resistance to penicillin was 0.2% for non-meningitis cases and 22.2% for meningitis cases; erythromycin resistance was reported in 42.9%, co-trimoxazole in 35.9%, and tetracycline in 42.9%.
CONCLUSIONS: Serotypes 14, 6B, 19A, 6A, and 19F were the most common serotypes isolated from children with IPD in Malaysia during this pre-vaccination era. The lack of reports on the serotype distribution has limited action for the implementation of PCV in the national immunization programme (NIP). The information from this study may benefit future policies for the introduction of PCV in the Malaysian NIP and ultimately may reduce the morbidity and mortality among children in Malaysia.
METHODS: We conducted a thorough literature search using PubMed without restrictions on publication date as well as Google Scholar to manually search for other relevant articles. Abstracts were included if they described data pertaining to Leptospira spp. in rats (Rattus spp.) from any geographic region around the world, including reviews. The data extracted from the articles selected included the author(s), year of publication, geographic location, method(s) of detection used, species of rat(s), sample size, prevalence of Leptospira spp. (overall and within each rat species), and information on species, serogroups, and/or serovars of Leptospira spp. detected.
FINDINGS: A thorough search on PubMed retrieved 303 titles. After screening the articles for duplicates and inclusion/exclusion criteria, as well as manual inclusion of relevant articles, 145 articles were included in this review. Leptospira prevalence in rats varied considerably based on geographic location, with some reporting zero prevalence in countries such as Madagascar, Tanzania, and the Faroe Islands, and others reporting as high as >80% prevalence in studies done in Brazil, India, and the Philippines. The top five countries that were reported based on number of articles include India (n = 13), Malaysia (n = 9), Brazil (n = 8), Thailand (n = 7), and France (n = 6). Methods of detecting or isolating Leptospira spp. also varied among studies. Studies among different Rattus species reported a higher Leptospira prevalence in R. norvegicus. The serovar Icterohaemorrhagiae was the most prevalent serovar reported in Rattus spp. worldwide. Additionally, this literature review provided evidence for Leptospira infection in laboratory rodent colonies within controlled environments, implicating the zoonotic potential to laboratory animal caretakers.
CONCLUSIONS: Reports on global distribution of Leptospira infection in rats varies widely, with considerably high prevalence reported in many countries. This literature review emphasizes the need for enhanced surveillance programs using standardized methods for assessing Leptospira exposure or infection in rats. This review also demonstrated several weaknesses to the current methods of reporting the prevalence of Leptospira spp. in rats worldwide. As such, this necessitates a call for standardized protocols for the testing and reporting of such studies, especially pertaining to the diagnostic methods used. A deeper understanding of the ecology and epidemiology of Leptospira spp. in rats in urban environments is warranted. It is also pertinent for rat control programs to be proposed in conjunction with increased efforts for public awareness and education regarding leptospirosis transmission and prevention.