Category Archives: Group B Streptococcus

Hong Kong – Do Not Eat Raw Freshwater Fish to Avoid Harmful Bacteria and Parasites

CFS

Consuming raw freshwater fish (Chinese Yu Sang) can be hazardous to health. Raw freshwater fish including grass carp, bighead carp or snakehead may carry parasites such as Chinese liver fluke, which can cause obstruction, inflammation and cancer of the biliary ducts in the liver. Chinese liver fluke contributes to the majority of local human cases of enteric parasites.

In addition to parasites, eating raw or undercooked freshwater fish can lead to foodborne infections. In the past, there were outbreaks of Group B streptococcus (GBS) infections in Singapore which were associated with raw freshwater fish consumption. GBS can cause infections in different parts of the body including the bloodstream, lungs, bones and joints. People, especially the elderly and people with weakened immunity (e.g. people with chronic diseases), may also contract GBS by exposure to seawater through an existing open wound or a puncture wound when handling raw aquatic products.

In order to protect public health, raw freshwater fish (Chinese Yu Sang) is a prohibited food under the Food Business Regulation (Cap 132X) in Hong Kong. Consumers are advised not to eat raw or undercooked freshwater fish while dining locally or travelling and eat freshwater fish only if it is adequately cooked, especially when having hot pot or congee.

To prevent foodborne diseases, the public should also pay attention to personal, food and environmental hygiene:

  • Always keep your hands clean
  • Cover all wounds when handling raw seafood, and wear protective gloves if possible
  • Store raw and cooked foods separately, and use different knives and cutting boards to handle them separately to avoid cross-contamination
  • Cook food thoroughly before eating

Research – Inactivation of foodborne and other pathogenic bacteria with pyrrolidine based fatty acid amide derivatives

Wiley Online

Abstract

Foodborne pathogens are a persistent threat to food and consumer safety. To mitigate outbreaks and contamination incited by these pathogens, the development of novel preventative safety controls and biorational inactivation measures are paramount. The objectives of this research were to evaluate the efficacy of pyrrolidine-based amide derivatives of decanoic (DEPY), lauric (LAPY), myristic (MYPY) and palmitic (PAPY) fatty acids for in-vitro inhibition and inactivation of various Gram-positive bacterial strains including Listeria monocytogenes (typically associated with foodborne illness), Bacillus subtilis, and Streptococcus mutans and Streptococcus sobrinus (both normally present in the oral cavity and involved with dental caries). Compared to no treatment (control), significant differences (P < 0.05) in the growth of Listeria strains were seen in-vitro with increased inhibition at higher amide concentrations (10,000–20,000 ppm). Furthermore, in-vitro growth inhibition of B. subtilisS. sobrinus, and S. mutans was also observed with an effectiveness of LAPY>MYPY>PAPY>DEPY. In co-inoculation assays, LAPY treatment significantly reduced Listeria growth from 1.55 to >5.0 Log CFU/mL when a concentration range of 5 to 250 ppm was applied. Moreover, Listeria populations on pathogen-inoculated produce were significantly (P < 0.05) reduced from 0.51 to >3.00 Log CFU/g with greater inactivation on carrots compared to alfalfa, soybean, and pistachio. These results demonstrated the potential value of these FA amides against Gram-positive pathogenic bacteria. Biorational applications of antibacterial FA amides on fresh produce as a postharvest intervention process offers a great potential for enhancement of food safety.

Research – Severe Streptococcus equi Subspecies zooepidemicus Outbreak from Unpasteurized Dairy Product Consumption, Italy

CDC

Abstract

During November 2021–May 2022, we identified 37 clinical cases of Streptococcus equi subspecies zooepidemicus infections in central Italy. Epidemiologic investigations and whole-genome sequencing showed unpasteurized fresh dairy products were the outbreak source. Early diagnosis by using sequencing technology prevented the spread of life-threatening S. equi subsp. zooepidemicus infections.

Streptococcus equi subspecies zooepidemicus is a β-hemolytic streptococcus expressing Lancefield group C antigen and is 1 of 3 S. equi subspecies. S. equi subsp. zooepidemicus is an opportunistic pathogen that can infect domestic animals, pets, and wildlife (16). Sporadic human cases have been reported (7), characterized by clinical manifestations that vary from meningitis to sepsis. Human infection generally occurs through direct contact with infected animals or by consumption of contaminated unpasteurized milk or other dairy products (810). We report a large S. equi subsp. zooepidemicus outbreak in Italy.

Research – Microbial Properties of Raw Milk throughout the Year and Their Relationships to Quality Parameters

MDPI

Raw milk microbiota is complex and influenced by many factors that facilitate the introduction of undesirable microorganisms. Milk microbiota is closely related to the safety and quality of dairy products, and it is therefore critical to characterize the variation in the microbial composition of raw milk. In this cross-sectional study, the variation in raw milk microbiota throughout the year (n = 142) from three farms in China was analyzed using 16S rRNA amplicon sequencing, including α and β diversity, microbial composition, and the relationship between microbiota and milk quality parameters. This aimed to characterize the contamination risk of raw milk throughout the year and the changes in quality parameters caused by contamination. Collection month had a significant effect on microbial composition; microbial diversity was higher in raw milk collected in May and June, while milk collected in October and December had the lowest microbial diversity. Microbiota composition differed significantly between milk collected in January–June, July–August, and September–December (p < 0.05). Bacterial communities represented in raw milk at the phylum level mainly included Proteobacteria, Firmicutes and Bacteroidota; PseudomonasAcinetobacterStreptococcus and Lactobacillus were the most common genera. Redundancy analysis (RDA) found strong correlations between microbial distribution and titratable acidity (TA), fat, and protein. Many genera were significantly correlated with TA, for example Acinetobacter (R = 0.426), Enhydrobacter (R = 0.309), Chryseobacterium (R = 0.352), Lactobacillus (R = −0.326), norank_o__DTU014 (R = −0.697), norank_f__SC-I-84 (R = −0.678), and Subgroup_10 (R = −0.721). Additionally, norank_f__ Muribaculaceae was moderately negatively correlated with fat (R = −0.476) and protein (R = −0.513). These findings provide new information on the ecology of raw milk microbiota at the farm level and contribute to the understanding of the variation in raw milk microbiota in China. View Full-Text

Research – Characterization of bacteria and antibiotic resistance in commercially-produced cheeses sold in China

Journal of Food Protection

The consumption of cheese in China is increasing rapidly. Little is known about the microbiota, the presence of antibiotic-resistant bacteria, or the distribution of antibiotic resistance genes (ARGs) in commercially-produced cheeses sold in China. These are important criteria for evaluating quality and safety. Thus, this study assessed the metagenomics of fifteen types of cheese using 16S rRNA gene sequencing. Fourteen bacterial genera were detected. Lactococcus , Lactobacillus , and Streptococcus were dominant based on numbers of sequence reads. Multidrug-resistant lactic acid bacteria were isolated from most of the types of cheese. The isolates showed 100% and 91.7% resistance to streptomycin and sulfamethoxazole, respectively, and genes involved in acquired resistance to streptomycin ( strB) and sulfonamides ( sul2) were detected with high frequency. To analyze the distribution of ARGs in the cheeses in overall, 309 ARGs from eight categories of ARG and nine transposase genes were profiled. A total of 169 ARGs were detected in the 15 cheeses; their occurrence and abundance varied significantly between cheeses. Our study demonstrates that there is various diversity of the bacteria and ARGs in cheeses sold in China. The risks associated with multidrug resistance of dominant lactic acid bacteria are of great concern.

Hong Kong – Hong Kong investigating Group B Streptococcus infections linked to fish

Food Safety News

Officials in Hong Kong are investigating an outbreak of invasive Group B Streptococcus cases linked to handling freshwater fish.

The Centre for Health Protection (CHP) of the Department of Health asked the public to not consume raw freshwater fish or aquatic products, and to handle such items with caution to avoid contact with wounds, including small cuts and scratches.

This past week, the Hospital Authority, an agency that manages public hospitals, told the CHP that 88 patients had tested positive for invasive Group B Streptococcus (GBS) in September and October, and provided specimens of 68 patients for genetic sequencing analysis.

This has shown that, amongst the 68 patients, 32 of them belonged to a variety of sequence type 283 (ST283), 27 cases are other serotypes or another strain of ST283, while the results for the remaining nine cases are pending.