Category Archives: Faecal Streptpcocci

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 – The Investigation of Changes in Bacterial Community of Pasteurized Milk during Cold Storage

MDPI

Abstract

The quality of pasteurized milk is commonly assessed through microbiological analysis, with variations in storage conditions significantly impacting the suppression of bacterial growth throughout the milk’s shelf life. This study investigated the dynamics of total bacterial counts (TBCs) and bacterial community shifts in milk that underwent pasteurization at 80 °C for 15 s. The milk was subsequently stored at 4 °C for varying intervals of 1, 4, 7, 10, 13, and 16 days. Culture-based testing revealed a significant TBC increase during the storage period spanning 1 to 16 days (up to −log10 4.2 CFU/mL at day 16). The TBC in pasteurized milk exhibited accelerated microbial growth from day 13 onwards, ultimately peaking on day 16. Bacillus was detected through 16S rRNA identification. Principal component analysis demonstrated a significant impact of storage time on bacterial communities in pasteurized milk. Analysis of bacterial diversity revealed a negative correlation between the Shannon index and the duration of pasteurized milk storage. Using high-throughput sequencing, Streptococcus and Acinetobacter were detected as prevalent bacterial genera, with Streptococcus dysgalactiae and Streptococcus uberis showing as dominant taxa. The presence of Streptococcus dysgalactiae and Streptococcus uberis in pasteurized milk might be attributed to the initial contamination from raw milk with mastitis. This study offers new evidence of the prevalence of bacterial community in pasteurized milk, thereby adding value to the enhancement of quality control and the development of strategies for reducing microbial risks.

Thailand issues Streptococcus suis warning as 2 dozen deaths reported

Food Safety News

Health officials in Thailand are urging people not to eat raw or undercooked pork after hundreds of cases and two dozen deaths were recorded.

From January to November 2023, there were 500 Streptococcus suis cases with 24 deaths in several different provinces, according to the Department of Disease Control (DDC).

Patients reported eating raw or undercooked pork, meals with pig’s blood as well as working with potentially infected animals.

Officials highlighted a trend on social media that involved eating raw food and drinking alcohol but said this puts people at risk of being infected.

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 – Enhanced antimicrobial effectiveness of synergistic mixtures of rambutan peel extract and cinnamon essential oil on food spoilage bacteria and bio-based food packaging

Wiley Online

Staph

This research aims to enhance antimicrobial activity of rambutan peel extract (RPE), by mixing with cinnamon essential oil (CEO). The mixture of RPE and CEO with different weight ratios (10:0, 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, 2:8, 1:9, and 0:10) had been prepared and the antimicrobial efficacy was tested. Nine strains of bacteria: Gram-positive bacteria (Bacillus sp., Enterococcus faecalisLeuconostoc sp., Micrococcus luteusStaphylococcus aureus, and Streptococcus sp.) and Gram-negative bacteria (Escherichia coliPseudomonas fluorescens, and Salmonella typhimurium) were selected as the representative of pathogenic and food spoilage bacteria. Mixing RPE with CEO in a ratio of 5:5 showed the best synergistic effect against those bacteria. Addition of RPE/CEO in a weight ratio of 5:5 improved the antimicrobial activity of whey protein isolated (WPI) films, and enhanced strength, stiffness, and water resistance of the film.

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.

Singapore – Tilapia linked to Streptococcus outbreak in Singapore

The Fish Site

Tilapia have been linked to an outbreak of Streptococcus, which affected 146 people in Singapore, prompting the FAO to issue a “risk profile report” to raise awareness of the threat.

In 2015, around 146 people became ill after eating a traditional raw freshwater fish dish in Singapore, with several people eventually having to have limbs amputated. It turns out that they had developed blood poisoning linked to a bacterium called Streptococcus agalactiae, also called Group B Streptococcus (SBS). The specific strain responsible for the outbreak was a unique sequence type 283 (ST283). A four-page factsheet, Invasive disease linked to raw freshwater fish, has just been made available, as has a more comprehensive Risk profile – Group B Streptococcus (GBS) – Streptococcus agalactiae sequence type (ST) 283 in freshwater fish.

Dr Tim Barkham, an associate professor at Tan Tock Seng Hospital in Singapore, first identified the human health risk. “Many microbiologists were surprised, as invasive GBS disease in people has not been known to be foodborne previously,” he said.

Research – Detection of pathogenic bacteria and fungi on biometric surface of Automated Teller Machines located in Brazilian public hospital

Academic Journals

The Automated Teller Machine (ATM) is used by millions of people as an alternative to gain time instead of using traditional banking systems in Brazil and ATMs are frequently localized in São Paulo city around the hospitals. However, ATMs might be potential devices for microbial accumulation and transmission in the community. The objective of the present study was to evaluate forty-two ATMs, in two hospital areas (A and B) in São Paulo city for the presence of pathogenic fungi and bacteria. Samples were collected from biometric surfaces of the devices with sterile cotton swabs soaked in the sterile physiologic saline and were cultured on selective agar for yeasts, filamentous fungi and bacteria in the period of January 2017 to March 2018. Complementary biochemical tests were applied to confirm the bacteria and the taxonomic identification of molds was performed considering the morphological characteristics by microscopic observation. Our results suggest that the biometric surfaces in ATMs is an important environmental source of microbes, once that the genera Staphylococcus was predominant in all agencies of both hospital areas (83.3%), following of Streptococcus spp. (57%) and Enterococcus spp. (50%). The group of Enterobacteriaceae (Gram negative bacilli) were most frequent in both areas studied (57%). Seven different fungi genera were isolated from ATMs in area A and B and yeasts were predominant in all samples collected (47%), comparing with filamentous fungi (23%). We conclude that biometric ATM surfaces play an important role in microbial transmission in hospital settings, and healthcare professionals should wash and disinfect their hands carefully before touching patients.