Microbiological Quality Control Research Articles

Microbiological quality control of wastewater by species identification of microorganisms using MALDI-TOF MS

Introduction. One of the main tasks of medical care for infectious diseases is the rapid identification of an infectious agent. The purpose of the study is to evaluate the effectiveness of the MALDI mass spectrometry for identification bacteria for microbiological control of wastewater quality. Materials and methods. Samples of wastewater samples at the treatment stage from the Kuryanovskaya aeration station were analyzed in accordance with MU 2.1.5.800-99 “Management of state sanitary and epidemiological supervision of wastewater disinfection” by the identification method in accordance with MUK 4.2.1884-04 “Sanitary-microbiological and sanitary - parasitological water analysis of surface water bodies” with application MALDI-TOF MS and 16S rRNA gene sequencing. Results. 5 strains of museum reference cultures and 22 bacterial isolates from wastewater samples grown on selective media of Endo, Enterococcus and Chromococcus coliform agar were studied, identified by MALDI-TOF MS, and confirmed by sequencing of specific regions of the 16S rRNA gene in bacteria of the genus Salmonella by MALDI-TOF MS identified only gender. Conclusion. In the routine practice of microbiological research, the identification of microorganisms is based on the determination of their cultural, tinctorial properties, and biochemical activity, the determination of which requires large financial and time costs. The use of the MALDI-TOF MS method makes it possible to reduce the time of identification of a microorganism when visible growth of microorganisms appears.

Recommendations on Describing the Requirements for Microbiological Quality and Sterility of Medicinal Products

The paper presents recommendations on describing analytical procedures for evaluation of medicinal products in terms of sterility and microbiological quality in accordance with the State Pharmacopoeia of the Russian Federation and the Pharmacopoeia of the EAEU. These quality attributes should be covered in Product specification files for any medicinal product. The paper describes specific considerations for preparation of the corresponding sections of the Russian or EAEU Product specification files. It is necessary to provide and justify quality requirements, refer to or describe the recommended analytical procedure and indicate differences, if any, from the standard one. Standardisation of the approach to microbiological quality control of medicinal products will allow analysts to accurately perform the tests, get reliable results and ensure the safety of medicinal products.

External quality control of microbiological testing in Polish medical diagnostic laboratories in 2020

<br><b>Introduction:</b>The paper presents the course of external quality control programmes organised in 2020 by the Centre of Quality Control in Microbiology (CQCM), including the 27<sup>th</sup> edition of the Polish National External Quality Assessment Scheme in Microbiology POLMICRO.</br> <br><b>Aim:</b>The assessment of the microbiological diagnostics’ quality carried out by Polish laboratories based on results of the POLMICRO, POLMICRO/MIKOLOGIA (MYCOLOGY), and POLMICRO/SSE programmes.</br> <br><b>Material and methods:</b>The participants’ responses from all rounds conducted in 2020 were analysed, i.e. five rounds of the POLMICRO programme, two rounds of the POLMICRO /MIKOLOGIA programme, and one round of POLMICRO/SSE.</br> <br><b>Results:</b>Positive evaluation in all rounds in the annual cycle were obtained by 90,1% of POLMICRO, 92,5% POLMICRO/MIKOLOGIA, and 100% POLMICRO/SSE participants.</br> <br><b>Conclusions:</b> Laboratories participating in the CQCM programmes demonstrated skills in the identification, antimicrobial susceptibility testing, and detection of resistance mechanisms of pathogenic microorganisms. The area of internal quality control of antimicrobial susceptibility testing requires improvement, especially the selection of reference strains.</br>

Adaptation and validation of a method for evaluating the bactericidal activity of ethyl alcohol in gel format 70% (w/w)

Ethyl alcohol 70% (w/w) is a broad-spectrum bactericidal agent that is mandatorily marketed as a gel in Brazil since 2002. However, there is no method described for the microbiological quality control of surface disinfectants in the form of gel, which makes it impossible to monitor the effectiveness of these products by the Health Surveillance. Thus, the present study aimed to adapt an analytical method and validate it so that it is possible to evaluate the bactericidal activity of ethyl alcohol-based disinfectants at 70% (w/w) in gel form. The proposed analytical method is an adaptation of a method developed by the Association of Official Analytical Chemists (AOAC), which is currently used to evaluate the bacterial activity of disinfectants in the form of spray and aerosol. The method consisted of challenging the disinfectant by putting it in contact with 60 carriers - previously contaminated with the test microorganism - during the contact time established by the manufacturer. The bacteria used in this work were Staphylococcus aureus CBRVS 00039 ATCC 6538, Salmonella enterica CBRVS 00028 ATCC 10708, and Pseudomonas aeruginosa CBRVS 00025 ATCC 15442. The parameters chosen for the validation of the method were: matrix effect, robustness, and repeatability. The experiments performed with a disinfectant matrix showed that there is no interference of the gel on the effectiveness of alcohol. Satisfactory results regarding the evaluation of bactericidal activity were obtained for the three microorganisms tested when the volume of 100 μL of disinfectant was applied. The method also showed good repeatability, as it proved to be robust with modification of incubation times, equipment and analysts. The development and validation of this method were extremely important for the quality monitoring of these products, besides being the first method described for the evaluation of gel disinfectants.

Water Quality Microbiological Inspection and Quality Control Technology

People’s lives are strongly linked to the quality of their drinking water. The quality of drinking water can be successfully ensured by testing microorganisms in water quality samples and examining their unqualified variables. Many urban residents’ drinking water contains a variety of microorganisms, which will have a direct impact on the quality of the water, and all microorganisms will offer a health risk. As a result, steps should be taken to eliminate germs. As a result, the focus of this article is on water quality microbiological inspection and quality control technology.

Development of Culture-Independent Detection Method for Beer Spoilage Lactic Acid Bacteria

In microbiological quality control of final beer products, 100–400 ml beer samples are traditionally filtered on a membrane filter, followed by a lengthy culturing process in/on a laboratory medium that usually requires 3–14 days. This study aims to detect beer spoilage lactic acid bacteria (LAB) in a culture-independent fashion, using a direct polymerase chain reaction (PCR) approach. In order to detect a trace level of spoilage LAB in beer products, pressure cycling technology was evaluated to determine if this technology could improve the direct recovery of DNA from membrane filters for PCR detection. In this study, a mixed cellulose ester filter was adopted to allow a larger volume of beer to be filtrated. As a result of the optimization of the DNA extraction process that minimizes the loss of DNA and the effect of PCR inhibitors, 100 (1–10) cells/300 ml beer were successfully detected for beer spoilage LAB. Furthermore, a challenge test using 3,000 ml beer showed that 100 cells of Levilactobacillus (Lactobacillus) brevis were detectable without the negative effects of beer-originated PCR inhibitors, indicating that a trace level of contamination, corresponding to 1 cell in 300 ml of beer products, is detectable. It was also shown that the test was completed in approximately 8 hours. Therefore, this newly developed method is considered to be useful for the culture-independent direct detection of an extremely low level of beer spoilage LAB without a traditional culturing process. Supplemental data for this article is available online at at.

Contaminants and Where to Find Them: Microbiological Quality Control in Axenic Animal Facilities.

The use of axenic animal models in experimental research has exponentially grown in the past few years and the most reliable way for confirming their axenic status remains unclear. It is especially the case when using individual ventilated positive-pressure cages such as the Isocage. This type of cage are at a greater risk of contamination and expose animals to a longer handling process leading to more potential stress when opened compared to isolators. The aim of this study was to propose simple ways to detect microbial contaminants with Isocages type isolator resulting by developing, validating and optimizing three different methods (culture, microscopy, and molecular). These three approaches were also tested in situ by spiking 21 axenic mice with different microorganisms. Our results suggest that the culture method can be used for feces and surface station (IBS) swabs exclusively (in Brain Heart Infusion for 7 days at 25°C and 37°C in aerobic conditions, and at 30°C in anaerobic conditions), while microscopy (wet mounts) and molecular method (quantitative PCR) were only suitable for fecal matter analyses. In situ results suggests that the culture and molecular methods can detect up to 100% of bacterial contamination events while the microscopy approach generates many erroneous results when not performed by a skilled microscopist. In situ results also suggest that when an axenic mouse is contaminated by a microbial agent, the microorganism will colonize the mouse to such an extent that detection is obvious in 4 days, in average. This report validates simple but complimentary tests that can be used for optimal detection of contaminants in axenic animal facilities using Isocage type isolators.

Determination of microbial recovery for some pharmaceutical raw materials and passive monitoring at production area and microbiology laboratory at Egyptian pharmaceutical company

Objective: This study aims to evaluate the validity of pharmaceutical raw materials obtained from an Egyptian pharmaceutical factory to ensure the accuracy of the examination findings before they are used in the manufacturing process. On the other hand, it also aims to determine the environmental microbial count at the microbiology laboratory and production areas to prevent microbial contamination during production and during microbiological analysis. Methods: Assessment of microbiological quality control according to pharmacopeia as plate method by using TSB media with a concentration of 0.1% tween 80, for passive monitoring using settled plate (TSA) media. Results: the percentage of microbial recovery for lactose monohydrate was 89%, 85%, 94%, 92%, 91%, and 91%, while Croscarmellose recorded 81%, 85%, 85%, 85%, and 88%, Mannitol recorded 86%, 85%, 91%, 83%, 86%, and 88%, Magnesium stearate recorded 91%, 85%, 94%, 89%, and 91%, and finally, Talc Powder recorded 94%, 85%, 94%, 91%, 87% and 85% for Pseudomonas aeruginosa, Salmonella enterica, Staphylococcus aureus, Candida albicans, Bacillus subtilis and Escherichia coli respectively for each pharmaceutical raw material. Methods of analysis recorded under acceptance criteria in the selected pharmaceutical factory according to pharmacopeia. On the other hand, the microbial quality of air for the production area selected by an Egyptian pharmaceutical company was under acceptance limits. Conclusion: All quality control methods and assessments of pharmaceutical raw materials, laboratories, and production areas must be performed to measure and control microbial contamination in the pharmaceutical industry and then produce high-quality pharmaceutical products free of microbial contamination, and methods of analysis must be recorded under acceptance criteria in the selected pharmaceutical factory according to pharmacopeia. On the other hand, the microbial quality of the air for the production area and microbiology laboratory that was selected by an Egyptian pharmaceutical company was under accepted limits. All quality control methods and assessments of pharmaceutical raw materials, laboratories, and production areas must be performed to measure and control microbial contamination in the pharmaceutical industry and then produce high-quality pharmaceutical products free of microbial contamination.

Applications of the Third-Generation DNA Sequencing Technology to the Detection of Hop Tolerance Genes and Discrimination of Saccharomyces Yeast Strains

To expand the applicability of the third-generation DNA sequencing technologies for the brewing industry, the new experimental protocols for quality control (QC) brewery laboratories have been developed, using the MinION system. Firstly, the hop tolerance genes, horA and horC, were amplified with multiplex PCR, and the PCR amplicons were sequenced by the MinION system. As a result, all of the beer spoilage lactic acid bacteria (LAB) strains carrying horA and/or horC were positively identified. Secondly, STA1, SbKEX2 and GEX1, were evaluated as diagnostic marker genes (DMGs) for discriminating Saccharomyces cerevisiae and S. pastorianus strains that possess essentially indistinguishable nucleotide sequences of the rDNA and internal transcribed spacer (ITS) regions. As a consequence of multiplex PCR specific to STA1, SbKEX2 and GEX1, these DMGs were shown to separate these hard-to-discriminate strains into four groups, namely top-fermenting ale yeast strains (S. cerevisiae), bottom-fermenting lager yeast strains (S. pastorianus), non-brewing S. cerevisiae wild yeast strains, and S. cerevisiae var. diastaticus. This study also demonstrated that the multiplexed PCR amplicons are independently recognized and correctly identified by the MinION system. Taken together, the newly developed methods using the MinION system are applicable to the identification and discrimination of important brewery microorganisms for microbiological QC. It was also shown that the concurrent applications of the rDNA-sequencing-based species identification and DMG approaches by the MinION system are useful for the breweries that now manufacture both traditional beers and non-traditional beverages. Supplemental data for this article is available online at https://doi.org/10.1080/03610470.2021.1939606 .

Use of natural plant extracts as a novel microbiological quality indicator in raw milk: An alternative for resazurin dye reduction method

In the present study, we propose a novel field-scale analytical tool for rapid screening of microbiological quality in raw milk using aqueous extracts of plant materials, i.e. flowers (e.g. Hibiscus rosa-sinensis L. and Clitoria ternatea), taproots (e.g. Beta vulgaris) and pricklypears (e.g. Opuntia dillenii). For each plant extract, the colour changes in raw milk were evaluated between 4.5 and 6.5 pH against the resazurin dye as a control. The plant anthocyanin content in each extract was analyzed by the differential pH method using a spectrophotometer. The Hibiscus rosa-sinensis flower extract was opted to further test since it had a pH-sensitive colour change (6.5; maroon to 6.2; light-pink) compared to other plant extracts, which did not indicate a noticeable colour variation with pH. Anthocyanin content of the Hibiscus extract was 0.59 g/mL. The novel method showed high linearity (R2 = 0.95), 100% accuracy and greater repeatability with an intermediate level of precision. The limit of quantification and detection was 0.46 and 0.15 g/mL, respectively. In conclusion, we demonstrated the potential in using water extract of Hibiscus rosa-sinensis L. flowers as an alternative to the resazurin dye reduction method for rapid and accurate microbiological quality control for raw milk procurement in remote areas.

Development and characterization of Lactobacillus acidophilus (LA-3) microparticles with reducing substances and its addition to Reino cheese

Probiotic microencapsulation provides additional protection to the microorganism, facilitating its survival in cheese. This study aimed to develop and to characterize Lb. acidophilus microparticles with l-cysteine hydrochloride and/or ascorbic acid and subsequently add them to Reino cheese. Four microparticles formulations were developed, the survival percentage of Lb. acidophillus was monitored during refrigeration (60 days) and the best formulation was characterized by morphology, distribution and size analysis. Three cheese formulations were developed, T1 (without Lb. acidophilus), T2 (containing free microorganism) and T3 (containing produced microparticles). The cheeses were analyzed after 1 and 25 days of ripening for the microbiological quality control parameters and viability of Lactobacillus spp. The encapsulation yield was over 80% in all microparticles. Formulation F3 showed 33 ± 0.16% lactobacilli survival even after 60 days, demonstrated the effect of the reducing substance added and had a mean diameter of 58 ± 1.51 μm and were spherical, smooth and uniform in shape. The T3 cheese containing the probiotic microparticles showed the highest lactobacilli viability (8.49 ± 0.08 Log CFU/g), provided additional protection to the Lb. acidophilus microorganism benefiting microbial cell survival, and therefore resulted in a ripened Reino cheese with functional probiotic potential for industrial cheese application.

Comparison of Different Temperature Conditions for Microbial Enumeration of Aspergillus brasiliensis in the Preservative Efficacy Test.

The preservative efficacy test is an important method for assessing the antimicrobial effect of cosmetic products. In this study, the optimum conditions for the efficient microbial enumeration of Aspergillus brasiliensis were investigated. Cosmetic products, inoculated with A. brasiliensis spore suspensions, were cultivated at 22.5°C, 32.5°C, or 40°C and the detection rate and the number of colonies were determined using the pour culture method. There was no difference in the viable counts of visible colonies among different temperature conditions. However, the viable counts after 3 days of culture were significantly greater for the cultures maintained at 32.5°C or 40°C compared with those maintained at 22.5°C. This effect was attenuated in products containing fatty acids, which could inhibit fungal growth. Overall, these results demonstrate that cultivating A. brasiliensis at 32.5°C reduces the time required for enumeration in the preservative efficacy test. Thus, the results of this study are expected to help improve and expedite microbiological quality control in the cosmetic industry.

Microbiological Analysis and pH Determination of Drinking Water Samples from Public Schools in the Municipality of Recife/PE

Water is considered a finite natural resource and one of the essential elements of life. It is used in various work activities such as agriculture, industry, livestock, public supply, energy generation, among others [15]. According to SPERLING (2006) [38], only 2.493% of the water on the planet is suitable for the consumption of humans and animals and 0.0007% of the water accessible for consumption is present in the atmosphere, rivers and lakes. It is estimated that more than one billion people worldwide do not have access to treated water, as its supply is not made on an equal basis due to population growth, economic activities and uneven distribution contrasted with different populations. between rural and urban areas [3, 21,33,]. Problems related to water shortages in the metropolitan regions of Brazilian states are increasingly present in everyday life, and can be attributed to factors involving administrative processes, such as the high cost of drinking water treatment, pollution of water tables, increased demand for water. consumption and climatic factors. In this sense, the use of water for poor quality consumption is an alternative for regions experiencing shortages and has a direct impact on the health of individuals, especially workers and students, as about 80% of the infectious and parasitic diseases that affect developing countries are due to poor quality water, directly impacting the individual’s health [10,17,18,28,36,37]. The water potability standards in Brazil are described in Ordinance GM / MS No. 2,914, of December 12, 2011, which portrays the main physical-chemical and microbiological quality control processes aimed at ensuring water safety and quality. for human consumption [5-8,42].In relation to water-borne infectious-parasitic diseases, their main route of transmission is via the oro-fecal route, that is, ingestion of water contaminated by excreta in drinks or food. According to PEIL et al (2015) [29], the main diseases resulting from contaminated water are typhoid fever, cholera, leptospirosis, giardiasis, enterobacteriosis, among others. In 2015, this type of disease was responsible for 2.35% of hospital admissions in Brazil, generating expenses for the Unified Health System (SUS) [28]. Among the diseases that affect individuals in the school phase, childhood diarrhea stands out for being responsible for hospitalizations and if left untreated, it can evolve to death. Childhood diarrhea is a serious public health problem in developing countries, such as Brazil, and is related to the lack of basic sanitation, ingestion of contaminated water and the precariousness of health services [35,40]. Vidal et al (2016) [43] comment that 88% of diarrhea cases are attributed to the consumption of contaminated water and children under five years of age are the most affected. The city of Recife, capital of the state of Pernambuco, has a large number of individuals in school, about 248,408 students are enrolled in the public school system. As a result, it is important to monitor and monitor the water used for consumption in schools. This work proposes to carry out microbiological analysis and pH determination of water for consumption in public schools located in the city of Recife/PE supplied by Pernambuco Sanitation Company (COMPESA).

METHOD DECISION FOR DETERMINING SPECIFIC MICROORGANISMS IN PHARMACEUTICAL PRODUCTS: AN OVERVIEW

In the direction of microbiological quality control analysis in pharmaceutical products, determining the microbiological load of the product at the end-use stage is very important for human health. Quality control parameters in pharmaceutical products vary according to the structure of the type of product and administration route. In this context, according to the pharmacopoeias, parenteral products and eye drops are classified as sterile products and the other group of pharmaceuticals are classified as non-sterile products. However, non-sterile pharmaceuticals also must have a certain microbiological quality. For this reason, the pharmaceuticals should have a certain microbiological load and should not contain defined microorganisms specified to its type. Since the control of the microbiological quality of the products is important for safety, it should be determined by quality control analysis. In this study, standard methods used to detect specific microorganism in pharmaceutical products were compared. Application steps in standard methods and identification tests of specific microorganisms were examined. In addition, studies that are alternative to standard methods were evaluated.
 Peer Review History: 
 Received: 5 September 2020; Revised: 20 October; Accepted: 28 October, Available online: 15 November 2020
 UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency.
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 Average Peer review marks at initial stage: 6.0/10
 Average Peer review marks at publication stage: 8.0/10
 Reviewer(s) detail:
 Dr. Mujde Eryilmaz, Ankara University,Turkey, meryilmaz@ankara.edu.tr
 Dr. Rawaa Souhil Al-Kayali, Aleppo University, Syria, rawah67@hotmail.com
 
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Quality control and immunomodulatory potential for clinical-grade equine bone marrow-derived mesenchymal stromal cells and conditioned medium

This study aimed to assess the safety and reproducibility of cell therapy for its use in clinical practice. We performed immunophenotypic characterization of equine bone marrow-derived mesenchymal stromal cells (BMMSCs) by flow cytometry using CD90, CD19, CD14, CD105, CD45, and HLA-DR markers (n = 4); GTG banding cytogenetic analysis (n = 3); and microbiological quality control (n = 4). The immunomodulatory potentials of BMMSCs (n = 4) and its conditioned medium (CM, n = 3) were investigated by in vitro lymphocyte inhibition assay using phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMCs). BMMSCs populations isolated from all animals showed high expression of CD90 and CD105, and low expression of CD19, CD4, CD45, and HLA-DR. Of the 60 metaphases analyzed, 5% presented aneuploidy on random chromosomes and no contamination was found based on microbiological analyses. Both treatments significantly inhibited lymphocyte proliferation (> 50%), compared with PHA-stimulated PBMCs (p < 0.0001). These promising results for BMMSCs and CM justify their potential as a therapeutic approach for inflammatory diseases. The techniques used in this study were effective in assessing the quality and determining the minimum criteria for the clinical use of BMMSCs in veterinary medicine.

The assessment of microbiological diagnostics’ credibility in Poland on the basis of the POLMICRO 2018 Programme results

POLMICRO programme – the Polish National External Quality Assessment Scheme in Microbiology is organized by the Centre of Quality Control in Microbiology (CQCM). The aim of the POLMICRO 2018 Programme was to evaluate proficiency of laboratories in the interpretation of Gram slides, identification of microorganisms, determination of susceptibility to antibiotics, detection of resistance mechanisms like ESBL, MBL, KPC, PRP or resistance of staphylococci to methicillin. Bacterial isolates distributed within the Programme differed in their susceptibility to antibiotics and the presence of various resistance mechanisms. The paper presents the results of the XXV edition – POLMICRO 2018.

Assessment of the correctness of identification and determination of antimicrobial susceptibility of Streptococcus pneumoniae in microbiological laboratories in Poland

The increase in bacterial resistance to antimicrobials is one of the most serious medical problems, therefore reliable identification in microbiological laboratories is important. The Polish National External Quality Assessment Scheme in Microbiological Diagnostics – POLMICRO programme is organized by the Centre of Quality Control in Microbiology (CQCM) enables the assessment of the competence of Polish microbiological laboratories in the field of identification, determination of susceptibility and detection of drug resistance mechanisms. This work presents the assessment of the results of identification and determination of S. pneumoniae antimicrobial susceptibility obtained by Polish laboratories during the 20 years of experience of the POLMICRO programme.

Spoilage Lactic Acid Bacteria in the Brewing Industry.

Lactic acid bacteria (LAB) have caused many microbiological incidents in the brewing industry, resulting in severe economic loss. Meanwhile, traditional culturing method for detecting LAB are time-consuming for brewers. The present review introduces LAB as spoilage microbes in daily life, with focus on LAB in the brewing industry, targeting at the spoilage mechanism of LAB in brewing industry including the special metabolisms, the exist of the viable but nonculturable (VBNC) state and the hop resistance. At the same time, this review compares the traditional and novel rapid detection methods for these microorganisms which may provide innovative control and detection strategies for preventing alcoholic beverage spoilage, such as improvement of microbiological quality control using advanced culture media or different isothermal amplification methods.

Occurrence of filamentous fungi isolated from matured blue cheese

Abstract Matured blue cheese can be made from cow's milk associated with the inoculated fungus Penicillium roqueforti, which guarantees specific sensorial characteristics. Recently, Brazil’s fine cheese production and consumption have increased by more than 200%, highlighting the relevance of microbiological quality control of these products. Fungal contaminations are responsible for significant losses in cheese production and provide a suitable environment for mycotoxins production, constituting a hazard to public health. In this work, we evaluated the mycological contamination profile of matured blue cheeses commercialized in Brazil. Samples of ten different brands were analyzed by serial dilution method, by plating in the Dicloran Rose of Bengal Chloramphenicol (DRBC) culture medium and Dicloran Glycerol Medium Base (DG18). Subsequently, different fungi morphotypes were isolated and morphologically identified. As a result, 461 fungi were isolated and identified, notably Aspergillus aculeatus, Penicillium roqueforti and Penicillium solitum. All samples were contaminated by filamentous fungi, amongst those, many already reported as mycotoxin producers, which underlines the relevance of microbiological monitoring.

Survey and Microbiological Quality Control of Commercial Probiotics for Livestock in South Korea

Survey and Microbiological Quality Control of Commercial Probiotics for Livestock in South Korea