Evaluation of approaches to increase the effectiveness of various disinfectants against biofilm communities of different ages

Disinfectants are used as the main agents against microorganisms circulating on the surfaces of food enterprises. However, the adaptive ability of microorganisms to form biofilms complicates the process of surface cleaning and reduces the effectiveness of disinfectants. Modern disinfectants act against freely circulating microflora, but it is known that they are not always effective against biofilms. The purpose of this study was to investigate effective disinfectant compositions with bactericidal effect on binary bacterial biofilms of different ages. The article describes the effects of disinfectants based on chlorine, peracetic acid and quaternary ammonium compounds with enzymes in concentrations recommended by the manufacturer and increased several times on Salmonella 38, Brochothrix thermosphacta 2726 and Staphylococcus equorum 2736 planktonic cultures and binary biofilms. Binary biofilms of different ages (2 and 9 days old) were exposed to disinfectants with various active ingredients in combination with adjuvants, i. e. hydrogen peroxide 6% and various concentrations of isopropyl alcohol (30%). All products in concentrations recommended by the manufacturer did not have a disinfectant effect against the studied biofilm cultures. As a result of the work, it was found that the most effective disinfectants against multispecies biofilms were quaternary ammonium compounds in combination with enzymes and chlorine in combination with isopropyl alcohol (30%). The results obtained allow to expand knowledge about effective methods for controlling biofilms.Disinfectants are used as the main agents against microorganisms circulating on the surfaces of food enterprises. However, the adaptive ability of microorganisms to form biofilms complicates the process of surface cleaning and reduces the effectiveness of disinfectants. Modern disinfectants act against freely circulating microflora, but it is known that they are not always effective against biofilms. The purpose of this study was to investigate effective disinfectant compositions with bactericidal effect on binary bacterial biofilms of different ages. The article describes the effects of disinfectants based on chlorine, peracetic acid and quaternary ammonium compounds with enzymes in concentrations recommended by the manufacturer and increased several times on Salmonella 38, Brochothrix thermosphacta 2726 and Staphylococcus equorum 2736 planktonic cultures and binary biofilms. Binary biofilms of different ages (2 and 9 days old) were exposed to disinfectants with various active ingredients in combination with adjuvants, i. e. hydrogen peroxide 6% and various concentrations of isopropyl alcohol (30%). All products in concentrations recommended by the manufacturer did not have a disinfectant effect against the studied biofilm cultures. As a result of the work, it was found that the most effective disinfectants against multispecies biofilms were quaternary ammonium compounds in combination with enzymes and chlorine in combination with isopropyl alcohol (30%). The results obtained allow to expand knowledge about effective methods for controlling biofilms

Factors influencingmicrobial transmission in a meat processing plant

The review paper examines the main risk factors for microbial contamination of meat at different stages of its processing. Particular emphasis has been placed on primary animal processing being the most hazardous in terms of microbial contamination of meat. Carcass cross-contamination most frequently occurs during skinning and evisceration since hides and the digestive tract are the primary sources of microbial pathogens. It is necessary to observe stringent sanitary and hygienic rules when performing these operations. Continuous cold chain management along all following stages of meat processing and control of the sanitary status of cold chambers during meat storage are of extreme importance. An increase in the microbial counts due to the high number of manual operations was observed during meat cutting, boning, and trimming. Subsequent stages of meat processing, including mincing, curing, the addition of spices, also promote significant microbial growth. Strict control regarding detection of dangerous pathogens, especially L. monocytogenes, is needed at this stage. In general, to minimize problems linked with meat and meat product safety, it is necessary to take timely measures on sanitary treatment of meat processing facilities, including the prevention of biofilm formation

Evaluating the effect of various types of disinfectants on bacterial biofilms

Biofilm formation on equipment surfaces is a potential food safety hazard, providing increased resistance and persistence of pathogens and spoilage microorganisms in food production environments. The issue of preventing the biofilm formation is extremely important, since a wide range of disinfectants does not always provide the proper effect. The article discusses the antimicrobial effectiveness of disinfectants with various active ingredients (based on active chlorine, peracetic acid and quaternary ammonium compounds (QAC) with enzymatic substances) on binary biofilms. The objects of the study were the strains of pathogenic and opportunistic microorganisms isolated from abiotic surfaces of food production environments and food products. Different effects of disinfectants on biofilms formed by bacteria have been established. Disinfectant based on peracetic acid and chlorine had the greatest effect on binary biofilms of Brochothrix thermosphacta/Salmonella spp. and Staphylococcus equorum/Salmonella spp. The greatest antimicrobial effect on biofilm of Listeria monocytogenes 12/Pseudomonas azotoformans 6 was shown by a chlorine-based disinfectant. Disinfectants based on chlorine and QAC with enzymatic substances were most effective against the binary biofilm of L. monocytogenes 12/Salmonella spp. 14. However, none of the disinfectants had absolute antimicrobial effectiveness against the studied binary biofilms. Biofilm-forming microorganisms have shown resistance to the recommended concentrations of disinfectants. Therefore, currently, it is extremely important to revise approaches to hygiene at enterprises by finding working concentrations of new antimicrobial agents and new procedure that are effective for destroying biofilms

Loop-mediated isothermal amplification (LAMP) method for fast detection of Campylobacter spp in meat food products and environmental objects of a processing plant’s

There is constant necessity of developing the accurate and fast methods for detection of foodborne pathogens. Microorganisms of Campylobacter genus are one of the main causes of foodborne diseases worldwide. Fast identification of Campylobacter at all stages of the food life cycle is an efficient strategy to control foodborne campylobacteriosis. This article the authors evaluated a commercial loop-mediated isothermal amplification (LAMP) system with bioluminescence, called as the 3M™ Molecular Detection Analysis (MDA), which was used to find Campylobacter in food products with the help of a certain standard method, which is referred to as the reference method. The results of this study showed that the commercial LAMP based method is as efficient as the reference method, and features high specificity and minimum determinability (sensitivity). The LAMP based method has been shown to be a fast and reliable method for detection of Campylobacter spp. scarce presence (10 CFU/25 g) in meat, meat products, as well as carcass swabs and production facilities’ environment. The LAMP analysis required about 24–27 hours to achieve a result. However the LAMP based method will facilitate the detection of Campylobacter, as it provides much easier and faster detection of Cam  pylobacter spp., including Campylobacter jejuni/Campylobacter coli, than standard microbiological methods. The LAMP based method is an efficient tool to prevent the spreading of Campylobacter spp. contamination in food products.There is constant necessity of developing the accurate and fast methods for detection of foodborne pathogens. Microorganisms of Campylobacter genus are one of the main causes of foodborne diseases worldwide. Fast identification of Campylobacter at all stages of the food life cycle is an efficient strategy to control foodborne campylobacteriosis. This article the authors evaluated a commercial loop-mediated isothermal amplification (LAMP) system with bioluminescence, called as the 3M™ Molecular Detection Analysis (MDA), which was used to find Campylobacter in food products with the help of a certain standard method, which is referred to as the reference method. The results of this study showed that the commercial LAMP based method is as efficient as the reference method, and features high specificity and minimum determinability (sensitivity). The LAMP based method has been shown to be a fast and reliable method for detection of Campylobacter spp. scarce presence (10 CFU/25 g) in meat, meat products, as well as carcass swabs and production facilities’ environment. The LAMP analysis required about 24–27 hours to achieve a result. However the LAMP based method will facilitate the detection of Campylobacter, as it provides much easier and faster detection of Cam  pylobacter spp., including Campylobacter jejuni/Campylobacter coli, than standard microbiological methods. The LAMP based method is an efficient tool to prevent the spreading of Campylobacter spp. contamination in food products

Prevalence of Listeria monocytogenes in meat products during 2017–2019 depending on technological factors and seasons

Microbiological examination of contamination of imported and domestic meat products with pathogenic bacteria Listeria monocytogenes depending on a meat type, technology and season was carried out during 2017–2019. In total, 2777 product samples were analyzed; the presence of this pathogen was revealed in 8.8% of products (244 positive samples). It was found that the prevalence of L. monocytogenes in meat products increased over three years of observation (2017–2019). The highest occurrence of this pathogen was found in poultry meat (on average 18.7%) followed by products from beef (13.2%). Meat products from mixed raw materials (beef and pork) accounted for 5.3% of tested samples, while in pork semi-finished products L. monocytogenes was found only in 3.2% of cases. It was noted that the technology of semi-finished products significantly affected the level of contamination of meat products with L. monocytogenes. Various technological approaches are used in the production process increasing the risk of contamination of the finished product since there is no timely data on Listeria contamination of raw materials used for production of a particular product. It has been established that a significant role in microbiological studies is played by various approaches to sample preparation of analyzed samples of meat cuts, semi-finished products in large and small pieces, as well as minced semi-finished products. Not knowing the real level of surface contamination with L. monocytogenes of carcasses, half-carcasses, semi-finished products in large pieces, manufacturers use such raw materials for the subsequent production of other types of semi-finished meat products, increasing the risk of manufacturing unsafe products with following contamination of equipment, work surfaces and other objects of the production environment. The highest occurrence of L. monocytogenes in meat products during three years of observation was found in the summer period (14.2%). The proportions of positive samples in the winter, spring and autumn months varied on average within 6.7–7.1%

ИДЕНТИФИКАЦИЯ МИКРОБИОЛОГИЧЕСКИХ РИСКОВ КОНТАМИНАЦИИ ТУШ КРУПНОГО РОГАТОГО СКОТА И СВИНЕЙ ПАТОГЕННЫМИ МИКРООРГАНИЗМАМИ ПРИ УБОЕ И ПЕРЕРАБОТКЕ

In this work, the risk of contamination of cattle and pig carcasses with pathogens at different stages of their slaughter and processing was assessed. The analysis of meat (carcasses, half carcasses and cuts) and meat semi-prepared products from beef and pork for the presence of the microorganisms of the genera Salmonella and Listeria, and Listeria monocytogenes in the samples taken by the destructive (from the depth) and nondestructive (from the surface) methods was carried out to determine the critical points. It was found that the deep layers of beef and pork cuts were not contaminated with the microorganisms of the genus Salmonella and L.monocytogenes. However, surface contamination of cattle and pig carcasses and half-carcasses with Salmonella and L.monocytogenes was revealed at the stages of hide removal and evisceration of the carcasses. Dry and wet cleaning of carcasses and half-carcasses did not facilitate the reduction of contamination. This fact is the cause of contamination of meat semi-prepared products (small-sized and minced), which was established during the study.В данной статье определяются риски контаминации патогенными микроорганизмами туш крупного рогатого скота и свиней на различных этапах их убоя и переработки. Для установления критических точек проведены исследования мяса (в тушах, полутушах и  отрубах) и  мясных полуфабрикатов из говядины и  свинины на наличие микроорганизмов рода Salmonella, Listeria и  бактерий вида Listeria monocytogenes в  образцах, отобранных деструктивными (из глубины) и  недеструктивными (с поверхности) методами. Установлено, что глубокие слои мясных отрубов из говядины и свинины не обсеменены микроорганизмами рода Salmonella и бактериями вида L.monocytogenes. Однако выявлена контаминация поверхности туш и полутуш крупного рогатого скота и свиней бактериями рода Salmonella и  L.monocytogenes на этапах съемки шкур и  извлечения из туш внутренних органов. Сухой и  мокрый туалет туш и полутуш не способствует снижению их обсеменённости. Данный факт является причиной контаминации мясных полуфабрикатов (мелкокусковых и  фаршевых), что было установлено при исследовании

КОНЦЕПТУАЛЬНЫЕ ПОДХОДЫ К ЭКСПРЕСС-ВЫЯВЛЕНИЮ CAMPYLOBACTER SPP. В МЯСЕ УБОЙНЫХ ЖИВОТНЫХ

The modern approach to quality assurance of food products based on the ISO 9000 standards indicates the need for the implementation of quality management systems in processing plants. According to the analysis of scientific publication databases (Science Direct and Web of Science), it is established that only 0.5–1.7% of publications are related to studying meat of slaughter animals (except for birds) concerning the presence of Campylobacter. The priority method of investigation is PCR. Ready-to-use PCR test system was developed for the detection of Campylobacter spp. on the basis of selected gene-specific primers to bacteria of Campylobacter genus. Specificity of the test system is established for Gram-negative bacteria of Salmonella, Escherichia, and Proteus genera, and for oxidase-positive Aeromonas. Gene-specific primers for Campylobacter were selected and ready-to-use PCR test system was developed on their basis. It was found that the selected primers have 100% convergence to the genome of Campylobacter genus bacteria, the PCR efficiency is not less than 95%, and the detection limit is not more than 1× 104 CFU/g. When estimating the specificity of the primers, it was taken into account that the bacteria of Campylobacter genus may be incorporated in a consortium with intestine microbiome, mainly with Enterobacteriaceae and lactic acid bacteria. However, Bolton’s enrichment medium is selective and, during the cultivation process, suppresses the growth of Gram-positive lactic acid bacteria. It was found that the selected primers were 100% specific and did not give false positive reactions with this group of microorganisms. The developed test system was successfully validated in a cycle of qualitative tests in the FEPAS system and implemented into laboratory practice. It was proved that the developed test system may be used both in screening at the stages of Campylobacter enrichment and in identification of pure culture of the microorganism.Современный подход формирования качества продуктов питания, основанный на стандартах ИСО серии 9000, указывает на необходимость внедрения систем менеджмента качества на перерабатывающих предприятиях. Согласно анализу баз данных научных публикаций Science Direct (by Scopus) и Web of Science установлено, что исследованию мяса убойных животных (кроме птицы) на наличие бактерий рода Campylobacter посвящено только 0,5–1,7% публикаций. Приоритетным методом исследования является ПЦР. Разработана готовая к применению ПЦР тест-система для выявления Campylobacter spp. на основе подобраных родоспецифичных праймеров к бактериям рода Campylobacter. Специфичность тест–системы установлена в отношении грамотрицательных бактерий родов Salmonella, Escherichia, Proteus, а также оксидазоположительных Aeromonas. Были подобраны родоспецифичные праймеры к бактериям рода Campylobacter и на их основе разработана готовая к применению ПЦР тест-система. Установлено, что подобранные праймеры имеют 100% сходимость к геному бактерий рода Campylobacter, эффективность ПЦР составляет не менее 95%, предел обнаружения не более 1× 104 КОЕ/г. При оценке специфичности праймеров учитывалось, что бактерии рода Campylobacter могут находиться в консорциуме, обоснованным микробиомом желудочно-кишечного тракта, в основном с бактериями семейства Enterobacteriaceae и молочнокислыми бактериями. Однако среда обогащения Болтон является селективной и в процессе культивирования подавляет рост Грамположительных молочнокислых бактерий. Установлено, что подобранные праймеры обладают 100% специфичностью и не дают ложноположительных реакций с указанной группой микроорганизмов. Разработанная тест-система была успешно проверена в раунде сличительных испытаний в системе FEPAS и внедрена в лабораторную практику. Доказано что разработанную тест-систему можно использовать как при скрининге на этапах обогащения бактерий рода Campylobacter, так и при идентификации чистой культуры микроорганизма

NOVOSIBIRSK REGION PROGRAM OF THE LIVER TRANSPLANTATION IN CHILDREN

The aim of the study was to analyze the early and late outcomes of pediatric liver transplantation (LTx) program in the Novosibirsk region. Material and Methods. The retrospective study included 24 patients aged 72 ± 74.8 months (from 4 to 212 months, median – 20 months) with a body weight of 21.7 ± 18.1 kg (from 4.5 to 55 kg, median – 12.5 kg). Two (8.3 %) cadaveric whole liver grafts, 19 (79.2 %) living donor liver grafts, and 3 (12.5 %) cadaveric liver fragments (reduced-size or split-liver) were transplanted. Results. The features of vascular and biliary reconstruction in different types of LTx are discussed. The incidence of vascular and biliary complications was 8.3 and 20.8%, respectively. The patients stayed in the intensive care unit for 9 ± 5.1 days (from 4 to 22 days, median 8 days) and total length of hospital stay was for 40 ± 25.4 days (from 19 to 136 days, median 32 days). Two (8.3 %) recipients had early graft dysfunction. Perioperative mortality (up to 90 days) was absent. The overall 5-year patient and graft survival rates were 95 and 88 %, respectively. Conclusion. The Novosibirsk region has a pediatric LTx program with outcomes comparable to the data of the leading world and Russian centers

Дифиллоботриоз: вопросы диагностики, терапии, профилактики

Helminthiases are found in the group of the most common and socially significant human infectious diseases. According to current data, at least 1 billion people are infected with helminths or pathogenic infections. One of the most important and widespread human biohelminth parasites in the Russian Federation is the broad-spectrum tapeworm (Diphyllobothrium latum). The absence of specific clinical diagnosis, as well as the predominance of latent forms, determines the presence of diphyllobothriasis disease. The aim of the study was to summarize current data on the epidemiology, pathogenesis, clinical and laboratory manifestations and therapy of diphyllobothriasis.  Materials and methods. Clinical cases of diphyllobothriasis were analyzed among patients who were treated in January to November 2022 in the departments of the daytime period of clinical observation of the infectious diseases hospital named after S.P. Botkin, as well as the department of incidents detected and the clinical diagnostic center of Pediatric Research and Clinical Center for Infectious Diseases. Cases of the use of diseases, data from laboratory and instrumental studies, and therapy were evaluated. The most informative of them is given as a clinical example. The article also describes in detail the current biological and epidemiological features of Diphyllobothrium latum, the characteristic clinical picture of diseases and the most frequent complications.  Results. Diphyllobothriasis still remains one of the most vulnerable biohelminthiases in Russia, typical for some patients of different ages. Verification of the diagnosis of “diphyllobothriasis” can be of the nature of an “accidental finding” during screening scatological or instrumental studies; upon admission, patients themselves begin to suspect helminthiasis when fragments of the strobila worm are found in the feces. To identify a conditional diagnosis of the pattern of clinical and laboratory infection (exclusion of a complicated course of diseases, helminthiases of a different etiology) and to determine risk factors for the transmission of diseases for the prevention of infections. Гельминтозы составляют группу наиболее распространенных и социально значимых инфекционных заболеваний человека. По современным данным, не менее 1 миллиарда людей инфицированы гельминтами или патогенными простейшими. Одним из наиболее крупных и широко распространённых в Российской Федерации биогельминтов-паразитов человека является лентец широкий (Diphyllobothrium latum). Отсутствие специфической клинической картины, а также преобладание латентных форм обусловливает трудности диагностики дифиллоботриоза. Цель: обобщение современных данных об эпидемиологии, патогенезе, клинико-лабораторных проявлениях и терапии дифиллоботриоза.  Материалы и методы. Проанализированы клинические случаи дифиллоботриоза среди пациентов, проходивших лечение в период с января по ноябрь 2022 г. в отделении дневного пребывания Клинической инфекционной больницы им. С.П. Боткина, а также в отделении кишечных инфекций и клинико-диагностическом центре Детского научно-клинического центра инфекционных болезней. Оценивались клинические проявления заболевания, данные лабораторных и инструментальных исследований, проводимая терапия. Наиболее информативный из них приведён в качестве клинического примера. В статье также подробно описаны актуальные биологические и эпидемиологические особенности Diphyllobothrium latum, характерная клиническая картина заболевания и наиболее частые осложнения.  Результаты. Дифиллоботриоз остается одним из наиболее распространённых биогельминтозов России, характерных для пациентов различных возрастов. Верификация диагноза «Дифиллоботриоз» может носить характер случайной находки при скриннинговых копрологических или инструментальных исследованиях, в ряде случаев пациенты сами начинают подозревать у себя гельминтоз при обнаружении в испражнениях фрагментов стробилы червя. Для установления окончательного диагноза целесообразно проведение клиниколабораторного обследования (исключение осложнённого течения заболевания, гельминтозов другой этиологии) и уточнения факторов риска передачи заболевания для профилактики повторных заражений.

Genetic markers of vascular pathology of the visual nerve

Purpose. Perform genotyping on two polymorphisms: del-425 and З'-UTR of the c-fms gene in elderly patients with coronary artery disease, hypertension and chronic cerebral insufficiency. Materials and methods. Genotyping was performed in 200 elderly patients using the allele of specific PCR at the del-425 and З'-UTR loci of the c-fms gene in DNA samples isolated by the standard method. Depending on the presence or absence of vascular pathology of the optic nerve, patients are divided into two groups. Results. Genetic markers of predisposition to the vascular pathology of the optic nerve were determined according to del-425 and З'-UTR polymorphisms of the c-fms gene, their relationship with the anthropopulation factor. Conclusion. Genetic predisposition to the pathology of the optic nerve occurs when the patient has coronary heart disease, arterial hypertension with manifestations of chronic vascular cerebral insufficiency.c-fms у пожилых больных с ИБС, АГ и хронической мозговой недостаточностью. Материалы и методы. Проведено генотипирование у 200 пожилых больных с помощью аллель специфической ПЦР, по локусам del-425 и З'-UTR гена c-fms в образцах ДНК, выделенных стандартным методом. В зависимости от наличия либо отсутствия сосудистой патологии зрительного нерва больные распределены на две группы. Результаты. Установлены генетические маркеры предрасположенности к сосудистой патологии зрительного нерва по полиморфизмам del-425 и З'-UTR гена c-fms, взаимосвязь их с антропопопуляционным фактором. Заключение. Реализация генетической предрасположенности к патологии зрительного нерва наступает при наличии у больного ишемической болезни сердца, артериальной гипертонии с проявлениями хронической сосудистой церебральной недостаточностью