ABSTRACT
Background and Aim: Among Streptococcus suis serotypes, S. suis serotype 2 is the most significant serotype that causes serious diseases in pigs and humans worldwide. The present study aimed to estimate the global prevalence of S. suis serotype 2 isolated from pigs, determine its trend, and explore the factors associated with this serotype. Materials and Methods: We retrieved relevant published studies from PubMed, Scopus, and the Web of Science. The retrieved citations were screened for possible inclusion. Relevant data were then extracted from the included studies. The random-effects model was used for all meta-analyses. A subgroup meta-analysis was used to assess the heterogeneity of the prevalence for four characteristics (continents, sampling organs, reporting unit, and pig's health status). A cumulative meta-analysis was performed to determine the cumulative prevalence over time. Meta-regression analysis was used to determine the trend of pooled prevalence of S. suis serotype 2 over time. Results: Of 600 articles retrieved, 36 studies comprising a total sample size of 6939 isolates or samples from 16 countries of four continents were included for meta-analysis. The pooled prevalence of S. suis serotype 2 isolated from pigs was 13.6% (95% confidence interval [CI], 10.7%-17.1%), with high heterogeneity among the included studies (Cochran's Q, 431.6; p < 0.001; I2 = 91.9%; Table-1). No statistical significance was observed among subgroups of the four characteristics examined. However, the pooled prevalence of S. suis serotype 2 was as high as 16.0% (95% CI, 12.5%-20.3%; n = 16) in diseased pigs compared with 9.9% (95% CI, 5.6%-17.0%; n = 15) in healthy pigs. The pooled prevalence of S. suis serotype 2 isolated from pigs did not significantly decrease over time [regression coefficient = -0.020 (95% CI, 0.046-0.006, p = 0.139)]. The pooled prevalence of S. suis serotype 2 isolated from pigs fluctuated slightly between 13.2% and 17.8% from 2007 to 2023, although the pooled prevalence gradually decreased from 30.6% in 1987 to over 20% in 2003. Conclusion: The global prevalence of S. suis serotype 2 isolated from pigs was estimated to be 13.6% (approximately 10% in healthy pigs and around 16% in diseased pigs). S. suis serotype 2 isolated from pigs did not change significantly over time. These results indicate that S. suis serotype 2 remains a problem for the pig industry and poses a threat to human health.
ABSTRACT
Oxidative stress is defined as an imbalance between reactive oxygen species (ROS) production and antioxidant defense mechanisms of the body. An overproduction of ROS leads to lipid and protein oxidation, injuring the cells both in normal and pathological conditions. Rice bran protein hydrolysates (RBH) has potent antioxidant, anti-inflammatory, anti-angiotensin converting enzyme (ACE) and hypolipidemic effects. Little is known, however, about the effects of RBH in dogs. The present study evaluated the antioxidative, anti-ACE and metabolic effects of RBH in adult dogs. Eighteen adult dogs were divided into 2 groups: control (n=7) and RBH supplemented groups (n=11), received a diet with the same nutritional compositions. The RBH supplemented group was fed with RBH 500 mg/kg body weight (BW) mixed with food for 30 days. BW, blood glucose, lipid profiles, liver enzymes, electrocardiography (ECG), plasma ACE activity, oxidative stress and antioxidant biomarkers were determined on day 0 and day 30 of supplementation periods. Results showed that RBH decreased oxidative stress and increased antioxidant biomarkers by significantly reducing plasma malondialdehyde (MDA) and protein carbonyl, enhanced blood glutathione (GSH) and improved the GSH redox ratio. Moreover, decreased LDL-C and increased HDL-C levels were found after RBH supplementation whereas BW, blood glucose, liver enzymes, plasma ACE activity, plasma catalase (CAT) and superoxide dismutase (SOD) activity and cardiac function were not significantly changed. These results suggest that RBH may help to lower the risk of oxidative stress and dyslipidemia in adult dogs.
