Food-borne parasitic zoonosis: Distribution of trichinosis in Thailand

Trichinosis is among the most common food-borne parasitic zoonoses in Thailand and many outbreaks are reported each year. This paper investigates the distribution of the disease in regions of north, north-east, central and south Thailand. Between the earliest recorded of outbreak of trichinosis in Mae Hong Son Province in 1962 and 2006, there have been 135 outbreaks involving 7340 patients and 97 deaths in Thailand. The highest number of cases, 557, was recorded in 1983. Most infected patients were in the 35-44 year age group, and the disease occurred more frequently in men than women during 1962-2003, with no significant sex difference during 2004-2006. Outbreaks were most common in the northern areas, especially in rural areas where raw and under-cooked pork and/or wild animals are eaten. Human infections occur annually in northern Thailand during communal feasts celebrating the Thai New Year. Trichinosis causes have been reported every year, supporting the need for planning education programs.

Bio-control of Some Food-Borne Pathogenic Bacteria by Bacteriophage

In recent years, researchers tended to bring new alternative to biological protective systems used in conservation of food and production of safe food. Use of bacteriophage against to pathogen bacteria in food was the most hopeful system in these methods about bio-control. Controls of bacteriophage for each pathogen species and subspecies and determination of phage-host originality are important because efficient bio-control was achieved. Researches concentrated on some food-borne pathogen bacteria such as E. coli O157：H7, Campylobacter, Salmonella and Listeria. In a consequence of these studies made as in vitro and in vivo, first commercial production of phage which will be used in foods was made in Netherlands. Also, it has been informed that use of phage is cost-efficient alternative as compared with other preservatives. This review, discussed application of bacteriophages as bio-control agents in food and advantages and disadvantages about uses of bacteriophages by taking into account antimicrobial characteristics of them.

Progress on the melanoidins produced by the Maillard reaction of fermented food and traditional Chinese medicine

FMs(Food-borne melanoidins)are brown high molecular weight polymers formed by the Mailiard reaction between carbohydrates and nitrogen-containing compounds during the processing of food or Traditional Chinese Medicine(TCM),and are widely found in food-borne products such as TCM concoctions,bakery,brewing,soy sauce,ferment and other food-borne products.FMs not only have a variety of biological activities,such as antioxidant,antibacterial,immunomodulation,regulation of intestinal flora,etc.,and can change the color,aroma and taste of food.The diversity of its components has become a research hotspot at home and abroad in recent years,with a wide range of application prospects.Therefore,this paper summarizes the existing information on FMs at home and abroad,mainly describes their preparation process,physicochemical properties,structural characteristics and functional activity research progress.Typical FMs,such as coffee,biscuits,wine and soy sauce in daily food,and Polygonatum,Perilla oil,Black ginseng,and Red jujube in T,were highlighted.Summarising the current status of research between the chemistry and pharmacodynamics of relevant FMs and presenting challenges and future recommendations for melanoidin research.In future research on FMs,one should pay more attention to basic research,especially isolation and purification and generation mechanisms,to further demonstrate the biological activity of FMs in vivo and in clinical trials.Thus,the potential value of its existence is deeply exploited to meet the needs of technology,production and health.

慢性细菌性前列腺炎对精子功能影响的研究

作者对慢性细菌性前列腺炎 (CBP)伴不育症患者 (31例 )及正常有生育男子 (15例 )的精子 ,以去透明带地鼠卵穿透试验 (HOP)、精子尾部低渗肿胀试验 (HOS)、精子头部DNA荧光染色有效精子计数 (ESC)为指标 ,探讨了慢性细菌性前列腺炎对精子受精能力、精子膜及DNA双螺旋结构的影响 .结果显示 :CBP组的精子穿卵率和受精卵外精子附着数及ESC均明显地低于对照组 (P<0 .0 0 1) ,CBP组的HOP亦低于对照组 (P <0 .0 5 ) .结果提示 :慢性前列腺炎可致精液成分发生改变 ,使精子膜结构完整性遭破坏致使精子受精能力降低 .

食源性细菌耐药性检测方法的研究进展

文章综述常用的扩散法、稀释法和Etest法,以及一些新兴的分子生物学和电化学药敏试验方法,对其原理、特点和局限性进行了简要分析,展望了食源性细菌药敏试验方法的未来发展方向和研究趋势,旨在为新型药敏试验方法的开发提供参考。

Isolation, serotype diversity and antibiogram of Salmonella enterica isolated from different species of poultry in India

Objective: To study the occurrence and serotype diversity of Salmonella isolates in different species of poultry(chicken, emu and duck) and determine their resistance pattern against various antibiotics of different classes.Methods: About 507 samples comprising 202 caecal contents and 305 fecal samples from chicken, emu and duck were processed for isolation of Salmonella enterica. Salmonellae were isolated and detected by standard protocol of ISO 6579 Amendment 1: Annex D. Genetic confirmation was also made by using 16 S r RNA genus specific PCR. Serotype specific PCR was also done to detect the most common serovars viz. Salmonella Enteritidis, Salmonella Typhimurium and Salmonella Gallinarum. All obtained isolates were subjected to a set of 25 antibiotics to study their antibiogram by using Baeur-Kirby disk diffusion method.Results: Out of 507 samples processed, 32 isolates of Salmonella enterica(18 from caecal contents and 14 from faecal samples) were obtained, of which 24 belonged to 6 different serovars, 6 were untypeable and 2 were rough strains. Salmonella Enteritidis was the most predominant serotype(9), followed by Salmonella Typhimurium(5), Salmonella Virchow(4), Salmonella Gallinarum(3), Salmonella Reading(2) and Salmonella Altona(1). Antibiotic resistance pattern was maximum(100%) to oxacillin, penicillin and clindamycin, followed by ampicillin(68.75%), tetracycline(65.62%), nalidixic acid(56.25%) and colistin(46.87%). High sensitivity of isolates was recorded for chloramphenicol(96.87%) followed by meropenem(84.37%). Conclusions: Occurrence of high proportion of serovars in our study which can cause serious gastroenteritis in humans is a matter of concern. Salmonella Altona has been detected for the first time in India from poultry. This serotype is known to cause serious outbreaks of gastroenteritis in humans. Multidrug resistant isolates were recovered at high percentage which can be attributed to non-judicious use of antibiotics both in prophylaxis and treatment regimen. This observation draws serious attention as poultry serves as an important source of transmission of these multidrug resistant Salmonella serovars to humans.

Isolation and identification of Salmonella from curry samples and its sensitivity to commercial antibiotics and aqueous extracts of Camelia sinensis(L.) and Trachyspermum ammi(L.)

Objective:To isolate Salmonella from curry samples and to evaluate the drug sensitivity of the food-borne Salmonella and its susceptibility to specific plant extracts.Methods:Salmonella was isolated from the curry samples by standard microbiological methods and was confirmed by biochemical tests.The antibiotic susceptibility test was conducted by disc diffusion method using commercially available antibiotics such as ampicillin,tetracycline,chloramphenicol,kanamycin,and penicillin.In addition,the susceptibility of the food-borne Salmonella was also evaluated against the aqueous extracts of Camelia sinensis(L.) Theaceae(tea leaves) and the Trachyspermum ammi(L.) Apiaceae(ajwain or omum seeds).Results:Out of fifty curry samples,only seven samples were identified to have Salmonella contamination.The Salmonella isolates showed a significant drug resistance pattern except for kanamycin.The plant extracts showed a considerable antibacterial activity against the isolates,indicating the presence of antimicrobial principle which can be exploited after complete pharmacological investigations.Conclusions:The present study demonstrates the occurrence of Salmonella in the curry samples,and shows significant drug resistance against most of the commercially available antibiotics,except kanamycin.Antimicrobial effect of the plant extracts against the food-bone Salmonella suggests that dietary including medicinal herbs would be one strategy to manage food borne pathogens.

全基因组测序在结核病研究中的应用进展

随着技术的发展及成本的降低，全基因组测序已经广泛应用于结核分枝杆菌的各方面研究当中，包括微进化与传播、宏观进化与种系发生、耐药检测等。根据现有研究成果，全基因组测序已经解决了很多传统分子研究方法无法解决的问题，比如鉴定传播链、分辨复发与再感染、解析结核分枝杆菌的进化过程、快速诊断结核病耐药、诊断混合感染等。尽管如此，目前还存在很多问题亟需解决。笔者对全基因组测序技术的研究方向及成果进行回顾，提出其局限性，并展望其应用前景。

Quantitative modeling of bacterial quorum sensing dynamics in time and space

Quorum sensing (QS) refers to the cell communication through signaling molecules that regulate many important biological functions of bacteria by monitoring their population density. Although a wide spectrum of studies on the QS system mechanisms have been carried out in experiments, mathematical modeling to explore the QS system has become a powerful approach as well. In this paper, we review the research progress of network modeling in bacterial QS to capture the system's underlying mechanisms. There are four types of QS system models for bacteria: the Gram-negative QS system model, the Gram-positive QS system model, the model for both Gram-negative and Gram-positive QS system, and the synthetic QS system model. These QS system models are mostly described by the ordinary differential equations (ODE) or partial differential equations (PDE) to study the changes of signaling molecule dynamics in time and space and the cell population density variations. Besides the deterministic simulations, the stochastic modeling approaches have also been introduced to discuss the noise effects on kinetics in QS systems. Taken together, these current modeling efforts advance our understanding of the QS system by providing systematic and quantitative dynamics description, which can hardly be obtained in experiments.

Deconvolution of the Error Associated with Random Sampling

In this work empirical models describing sampling error (&#916;) are reported based upon analytical findings elicited from 3 common probability density functions (PDF): the Gaussian, representing any real-valued, randomly changing variable x of mean &#956;?and standard deviation &#963;the Poisson, representing counting data: i.e., any integral-valued entity’s count of x (cells, clumps of cells or colony forming units, molecules, mutations, etc.) per tested volume, area, length of time, etc. with population mean of &#956;?and;binomial data representing the number of successful occurrences of something (x+) out of n observations or sub-samplings. These data were generated in such a way as to simulate what should be observed in practice but avoid other forms of experimental error. Based upon analyses of 104 &#916;?measurements, we show that the average &#916;?() is proportional to ?(&#963;x&#8226;&#956;-1;Gaussian) or ?(Poisson & binomial). The average proportionality constants associated with these disparate populations were also nearly identical (;±s). However, since ?for any Poisson process, . In a similar vein, we have empirically demonstrated that binomial-associated ?were also proportional to &#963;x&#8226;&#956;-1. Furthermore, we established that, when all ?were plotted against either ?or &#963;x&#8226;&#956;-1, there was only one relationship with a slope = A (0.767 ± 0.0990) and a near-zero intercept. This latter finding also argues that all , regardless of parent PDF, are proportional to &#963;x&#8226;&#956;-1?which is the coefficient of variation for a population of sample means (). Lastly, we establish that the proportionality constant A is equivalent to the coefficient of variation associated with &#916;?() measurement and, therefore, . These results are noteworthy inasmuch as they provide a straightforward empirical link between stochastic sampling error and the aforementioned Cvs. Finally, we demonstrate that all attendant empirical measures of &#916;?are reasonably small (e.g., ) when an environmental microbiome was well-sampled: n = 16 - 18 observations with &#956;&#8764;3?isolates per observation. These colony counting results were supported by the fact that the two major isolates’ relative abundance was reproducible in the four most probable composition observations from one common population.

Survival of some food-borne bacteria in kefir produced by microbial levan and pullulan

Kefir is a fermented milk product produced by kefir grains traditionally or lyophilized starter culture.Some quality characteristics of kefir produced at 22℃ and 30℃ using kefir grains after addition of microbial levan and pullulan were investigated for 14 days.Additionally,the survival of different Gram-positive and Gram-negative bacteria strains which were inoculated before and after fermentation were investigated during storage.The pH and titratable acidity were in the ranges of 4.67–4.39 and 1.10–0.87%,respectively.The highest exopolysaccharide values(458.3–465.3 mg/kg)were found in the samples produced with the addition of 1%(w/v)of microbial levan at 30℃.Yeast counts were in the ranges of 6.73–5.11 log CFU/mL while the lactobacilli and lactic streptococci counts were in the ranges of 9.64–7.91 and 9.64–8.69 log CFU/mL,respectively.The microbial polysaccharide addition did not show any significant differences in the enumeration of lactic acid bacteria in kefir(p>0.05).All Gram-positive and Gram-negative bacteria grew/survived during fermentation however Listeria monocytogenes was the most susceptible test bacterium to metabolites during storage.The highest reduction in the counts of L.monocytogenes was determined as 2.39 log units after 24 h of fermentation at 30℃ in the samples which were inoculated before fermentation and produced with the addition of pullulan.Kefir samples produced at 30℃ without polysaccharide addition were considered as the best with respect to appearance,taste,consistency and overall acceptability.

Quantum dot biosensor combined with antibody and aptamer for tracing food-borne pathogens

Due to the increasing number of food-borne diseases,more attention is being paid to food safety.Food-borne pathogens are the main cause of food-borne diseases,which seriously endanger human health,so it is necessary to detect and control them.Traditional detection methods cannot meet the requirements of rapid detection of food due to many shortcomings,such as being time-consuming,laborious or requiring expensive instrumentation.Quantum dots have become a promising nanotechnology in pathogens tracking and detection because of their excellent optical properties.New biosensor detection methods based on quantum dots are have been gradually developed due to their high sensitivity and high specificity.In this review,we summarize the different characteristics of quantum dots synthesized by carbon,heavy metals and composite materials firstly.Then,attention is paid to the principles,advantages and limitations of the quantum dots biosensor with antibodies and aptamers as recognition elements for recognition and capture of food-borne pathogens.Finally,the great potential of quantum dots in pathogen detection is summarized.

Antimicrobial effects of carnosic acid,kaempferol and luteolin on biogenic amine production by spoilage and food-borne pathogenic bacteria

Antimicrobial effects of carnosic acid,kaempferol and luteolin on biogenic amine(BA)production by five spoilage(Photobacterium damselae,Proteus mirabilis,Enterobacter cloacea,Pseudomonas luteola and Serratia liquefaciens)and five food-borne pathogenic bacteria(Staphylococcus aureus ATCC29213,Enterococcus faecalis ATCC29212,Escherichia coli ATCC25922,Salmonella Paratyphi A NCTC13 and Yersinia enterocolitica NCTC 11175)were investigated.The formation of ammonia(AMN),trimethylamine(TMA)and BAs by all bacterial strains were observed using ornithine decarboxylase broth.BAs,AMN,and TMA were determined by using high performance liquid chromatography(HPLC)method.The results showed that significant differences were observed(P≤0.05)in formation among spoilage and also food-borne bacteria.The impact of phenolic compounds on AMN,TMA and BAs production was dependent on bacterial strains.When total amount of cadaverine(CAD),putrescine(PUT),histamine(HIS)and tyramine(TYR)was considered,the phenolic compounds presented antimicrobial activity against fish spoliage bacteria and food-borne pathogens following the order;kaempferol>carnosic acid>luteolin.These phenolics have potential to be used as food preservatives.

Comparative prevalence of pathogenic and spoilage microbes in chicken sausages from Egypt and Greece

This study investigated the spread of foodborne pathogens: Listeria monocytogenes, Es-cherichia coli O157:H7, Staphylococcus aureus and Salmonella in chicken sausage samples collected from retail markets in Greece and Egypt during 2006 and from Egypt through 2010. Other microbiological parameters;total viable count (TVC), lactic acid bacteria (LAB), pseudomonads (PS), staphylococci (STAPH), Brochothrix thermosphacta (BT), Enterobacteriaceae (EN), Escherichia coli (EC), yeasts and moulds (Y&M) were also counted. Egyptian chicken sausage samples were found to harbor L. mono- cytogenes, Staph. aureus and E. coli O157:H7;with frequencies equivalent to 24%, 60% and 26% of the total samples during 2006 and 37.87%, 64.44% and 41.11% of the total samples during 2010, respectively, while Greek samples were entirely free of theses pathogens. Enrichment techniques indicated the absence of Salmonella from both Greek and Egyptian samples. The obtained results may mobilize food producers and handlers in developing countries to take the due measures reducing food-borne pathogen risks and spoilage flora alongside the poultry chain.

Isolation of <i>Bacillus cereus</i>in a Facility Preparing School Meals

Food safety is a fundamental requirement in mass catering, as large numbers of meals are served each day to potentially vulnerable consumers, such as children. Food Business Operators implement plans for the microbiological monitoring of the meals prepared and served in the catering sector, and for the swab-sampling of surfaces. From January 2018 to June 2019, our laboratory analyzed both food and swab samples from four catering facilities. Considering the EFSA 2018 data, we specifically focused on samples analyzed for Bacillus cereus. Our data substantially showed episodic contamination due to a piece of equipment that is not usually subjected to microbiological control, thus suggesting that every aspect should be scrutinized in order to identify critical points. While Bacillus cereus is widespread in nature and common in soil, it is adapted for growth in the intestinal tracts of insects and mammals. It is often present in a variety of foods, and may cause an emetic or a diarrheal type of food-associated illness. B. cereus produces several toxins. Multiplex PCR enables seven toxin genes to be detected (hblC, hblD, hblA, nheA, nheB, nheC and cytK).

Antimicrobial Activity of Wild Plant Seed Extracts against Human Bacterial and Plant Fungal Pathogens

Five wild plant species belonging to different families (Chenopodium album, Plantago major, Elytrigia elongata, Filipendula ulmaria and Nigella sativa) widely spread in Russian Federation and the former USSR were evaluated for their ability to inhibit growth of two important human food-borne pathogens (Escherichia coli O157:H7 and Listeria monocytogenes strain EGD-e) and eight plant pathogens (Alternaria alternata, Alternaria tenuissima, Bipolaris sorokiniana, Stagonospora nodorum, Fusarium solani, Fusarium oxysporum, Fusarium culmorum and Phytophtora infestans). To isolate biologically active compounds from seeds, a step-wise procedure including extraction with hexane, ethyl acetate, ethanol, and 10% acetic acid followed by reversed-phase HPLC was developed. Using disc-diffusion assay, the highest activity against E. coli O157:H7 was observed with extracts from F. ulmaria (hexane and ethyl acetate extracts and the unbound RP-HPLC fraction) and P. major (ethyl acetate extract and the unbound RP-HPLC fraction);E. elongate (the unbound RP-HPLC fraction) was less active. The extracts from P. major and E. elongate (the unbound RP-HPLC fractions) were equally highly active against L. monocytogenes, while those of F. ulmaria (the unbound RP-HPLC fraction) and N. sativa (hexane and ethyl acetate extracts) were less active against this pathogen. The dynamics of L. monocytogenes EGD-е and E. coli O157:H7 growth in the presence of two most potent extracts (RP-HPLC-unbound fractions of P. major and E. elongate and the hexane extract of F. ulmaria) was studied.

Grape Phenolic Extract Potentially Useful in the Control of Antibiotic Resistant Strains of <i>Campylobacter</i>

In this work, a grape phenolic extract obtained by methanol extraction has been demonstrated to be effective in inhibiting the growth of different strains and species of Campylobacter, one of the most important bacterial foodborne pathogens causing gastroenteritis worldwide. Noteworthily, it was particularly effective against several strains presenting multiple antibiotic resistances. In all cases, the minimum inhibitory concentration (MIC) was lower than 300 mg GAE/L, being of 60 mg GAE/L for one of the most resistant strains (C. coli LP2), while the others were between 120 mg GAE/L and 180 mg GAE/L. The analytical study of the main phenolic compounds in the grape extract revealed that it was mainly constituted by catechins (85.7%) and phenolic acids (13.7%). However, experiments developed using pure standards demonstrate that phenolic acids (such as gallic, p-hidroxibenzoic, vanillic, and homovanillic acids) were the most active, provoking a Campylobacter growth decrease between 6.7 and 7.6 log, while epicatechin was the only catechin with activity as pure compound (1 log of growth decrease).

Marine Fish Toxins in Thailand: Report of 6 Suspected Ciguatera Cases

Food poisoning or gastroenteritis is a common diagnosis for individuals who have nausea, vomiting and diarrhea after ingestion of fish. When also manifesting neurological symptoms, these are blamed on puffer fish poisoning, but ciguatera fish poisoning (CFP) can also manifest only with gastroenteritis, without neurological complications and remain undiagnosed. We report patients who fulfilled criteria of CFP suffering from severe GI disturbances, neurological manifestations, compromised cardiovascular status and autonomic dysfunction. All recovered within 1 - 3 days with supportive treatment. There were two small outbreaks: one in Bangkok in 2007 (2 patients) and another (2009) in Phuket (4 patients). All patients consumed the same unidentified fish portion and had severe GI symptoms. One had acute ventilatory failure requiring intubation whereas the remaining had neurological disturbances consisting of paresthesia, severe vertigo and ataxia. Absence of reflex tachycardia was noted in all patients who had severe volume depletion and shock. The most severe patient could be extubated within 24 hours and was discharged in 48 hours. All of the remaining recovered completely within 48 hours. Severe abdominal pain, nausea and vomiting and autonomic dysfunction in the form of bradycardia in the presence of hypotension were seen. Dramatic recovery within 48 hours occurred in all cases. None of the fish considered to have been responsible was available for testing. Physicians should be aware of CFP intoxication in the differential diagnosis of gastroenteritis-like syndromes after eating seafood.

Natural bioactive substances for the control of food-borne viruses and contaminants in food

Food-borne viruses and contaminants,as an important global food safety problem,are caused by chemical,microbiological,zoonotic,and other risk factors that represent a health hazard.Natural bioactive substances,originating from plants,animals,or microorganisms,might offer the possibility of preventing and controlling foodborne diseases.In this contribution,the common bioactive substances such as polyphenols,essential oils,proteins,and polysaccharides which are effective in the prevention and treatment of food-borne viruses and contaminants are discussed.Meanwhile,the preventive effects of natural bioactive substances and the possible mechanisms involved in food protection are discussed and detailed.The application and potential effects of natural bioactive substances in the adjuvant treatment for food-borne diseases is also described.

Bacteriocins as antimicrobial and preservative agents in food:Biosynthesis,separation and application

Emerging evidence shows the trend of using safe and natural preservatives like bacteriocins in food processing.The increasing demand by the food industry to extend keeping quality and prevent spoilage of various food products has appealed for new preservatives and new methods of conservation.Further,to discover the novel spectrum of antimicrobial compounds that could effectively battle food-borne pathogens,bacteriocins have been intensively studied in the last few years.Recently,great attention has been paid to the application of lactic acid-bacterial bacteriocins targeting food spoilage-causing or pathogenic microorganisms with no significant side effects.Different mechanisms of action like pore-formation,retarding cell-wall/nucleic acid/protein synthesis have been proposed and described for diverse bacteriocins.Therefore,the syntheses,purification of bacteriocins in addition to their applications as antimicrobial and preservative agents in food processing are reviewed in detail.The review will also discuss the preservative effect of bacteriocins and their combinations having multiple modes of action(hurdle approach)to reduce the microbial load as well as antimicrobial resistance.