Application and evaluation of matrix-assisted laser desorption ionization time-of-flight mass spectrometry in environmental pollution investigation of blood collection and supply institutions / 中国输血杂志

【Objective】 To investigate the environmental pollution of blood collection and supply institutions by using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and evaluate its application value. 【Methods】 Colonies of air from blood donation sites, skin puncture sites of blood donors, platelet storage boxes, platelet collection equipment, object surfaces of related experimental consumables and cuff surfaces of staff after disinfection were collected, and typical colonies after cultivation were selected for microbial identification by microbial mass spectrometry and then compared with bacteria results detected in blood components from May 2017 to May 2021. 【Results】 Aseptic growth, the number of colonies ≤4.0 CFU/ dish, and the number of colonies > 4.0 CFU/dish accounted for 21.20%, 62.20% and 16.60%, respectively. The qualified rate from high to low was platelet storage box, bacteria settling in the air of blood donation room after disinfection, platelet collection equipment, skin puncture site of blood donors after disinfection, the surface of platelet consumables and the surface of medical staff's overalls. After disinfection, the blood donors' skin puncture sites were compared with other collection sites, and the t values were 2.0371, 1.508, 2.109, 1.961 and 1.778, respectively, with no significant difference (P>0.05). Thirty cases of bacterial contamination of blood components were detected from May 2017 to May 2021, among which the detection rate of apheresis platelets was the highest, and the t values were 1.731 and 2.272, relative to the contamination frequency of erythrocytes and plasma bacteria (P>0.05), while the t value was 2.875, relative to concentrated platelets, with significant difference (P<0.05). 【Conclusion】 Bacterial contamination of blood components mostly come from air bacteria settling, blood donors' arms and skin after disinfection, and surfaces of related equipment and materials. Therefore, it is of clinical significance to conduct strict disinfection of working sites, establish disinfection monitoring methods and formulate disinfection hygiene standards in blood stations.

Rapid identification of microbial contaminants in pharmaceutical products using a PCA/LDA-based FTIR-ATR method

Microbiological quality of pharmaceuticals is fundamental in ensuring efficacy and safety of medicines. Conventional methods for microbial identification in non-sterile drugs are widely used; however they can be time-consuming and laborious. The aim of this paper was to develop a chemometric-based rapid microbiological method (RMM) for identifying contaminants in pharmaceutical products using Fourier transform infrared with attenuated total reflectance spectrometry (FTIR-ATR). Principal components analysis (PCA) and linear discriminant analysis (LDA) were used to obtain a predictive model capable of distinguishing Bacillus subtilis (ATCC 6633), Candida albicans (ATCC 10231), Enterococcus faecium (ATCC 8459), Escherichia coli (ATCC 8739), Micrococcus luteus (ATCC 10240), Pseudomonas aeruginosa (ATCC 9027), Salmonella typhimurium (ATCC 14028), Staphylococcus aureus (ATCC 6538), and Staphylococcus epidermidis (ATCC 12228) microbial growth. FTIR-ATR spectra provide data on proteins, DNA/RNA, lipids, and carbohydrates constitution of microbial growth. Microbial identification provided by PCA/LDA based on FTIR-ATR method were compatible with those obtained using traditional microbiological methods. The chemometric-based FTIR-ATR method for rapid identification of microbial contaminants in pharmaceutical products was validated by assessing the sensitivity (93.5%), specificity (83.3%), and limit of detection (17-23 CFU/mL of sample). Therefore, we propose that FTIR-ATR spectroscopy may be used for rapid identification of microbial contaminants in pharmaceutical products and taking into account the samples studied

Rapid identification of microbial contaminants in pharmaceutical products / Identificação rápida de contaminantes microbianos em produtos farmacêuticos

A qualidade microbiológica de medicamentos é fundamental para garantir sua eficácia e segurança. Os métodos convencionais para identificação microbiana em produtos não estéreis são amplamente utilizados, entretanto são demorados e trabalhosos. O objetivo deste trabalho é desenvolver método microbiológico rápido (MMR) para a identificação de contaminantes em produtos farmacêuticos utilizando a espectrofotometria de infravermelho com transformada de Fourier com reflectância total atenuada (FTIR-ATR). Análise de componentes principais (PCA) e análise de discriminantes (LDA) foram utilizadas para obter um modelo de predição com a capacidade de diferenciar o crescimento de oriundo de contaminação por Bacillus subtilis (ATCC 6633), Candida albicans (ATCC 10231), Enterococcus faecium (ATCC 8459), Escherichia coli (ATCC 8739), Micrococcus luteus (ATCC 10240), Pseudomonas aeruginosa (ATCC 9027), Salmonella Typhimurium (ATCC 14028), Staphylococcus aureus (ATCC 6538) e Staphylococcus epidermidis (ATCC 12228). Os espectros de FTIR-ATR forneceram informações quanto à composição de proteínas, DNA/RNA, lipídeos e carboidratos provenientes do crescimento microbiano. As identificações microbianas fornecidas pelo modelo PCA/LDA baseado no método FTIR-ATR foram compatíveis com aquelas obtidas pelos métodos microbiológicos convencionais. O método de identificação microbiana rápida por FTIR-ATR foi validado quanto à sensibilidade (93,5%), especificidade (83,3%) e limite de detecção (17-23 UFC/mL de amostra). Portanto, o MMR proposto neste trabalho pode ser usado para fornecer uma identificação rápida de contaminantes microbianos em produtos farmacêuticos

Microbiological quality of pharmaceuticals is fundamental in ensuring efficacy and safety of medicines. Conventional methods for microbial identification in non-sterile drugs are widely used, however are time-consuming and laborious. The aim of this paper was to develop a rapid microbiological method (RMM) for identification of contaminants in pharmaceutical products using Fourier transform infrared with attenuated total reflectance spectrometry (FTIR-ATR). Principal components analysis (PCA) and linear discriminant analysis (LDA) were used to obtain a predictive model with capable to distinguish Bacillus subtilis (ATCC 6633), Candida albicans (ATCC 10231), Enterococcus faecium (ATCC 8459), Escherichia coli (ATCC 8739), Micrococcus luteus (ATCC 10240), Pseudomonas aeruginosa (ATCC 9027), Salmonella Typhimurium (ATCC 14028), Staphylococcus aureus (ATCC 6538), and Staphylococcus epidermidis (ATCC 12228) microbial growth. FTIR-ATR spectra provide information of protein, DNA/RNA, lipids, and carbohydrates constitution of microbial growth. Microbial identification provided by PCA/LDA based on FTIR-ATR method were compatible to those obtained using conventional microbiological methods. FTIR-ATR method for rapid identification of microbial contaminants in pharmaceutical products was validated by assessing the sensitivity (93.5%), specificity (83.3%), and limit of detection (17-23 CFU/mL of sample). Therefore, the RMM proposed in this work may be used to provide a rapid identification of microbial contaminants in pharmaceutical products

Verification Process of American CLSI M52-Commercial Microbial Identification System and Antimicrobial Susceptibility Testing System / 现代检验医学杂志

Before performing patient testing with commercial microbial test systems,each laboratory must verify that it can obtain performance specifications comparable to those of the manufacturer.This includes trueness,precision (reproducibility),and reportable range of test results,and verifying that the manufacturer's reference ranges are appropriate for the laboratory's patient population.American Clinical and Laboratory Standards Institute has set up a committeeto develop a verification process and a quality assurance program for commercial microbial identification system and antimicrobial susceptibility testing system,in order to provide recommendations for US Food and Drug Administration (FDA).This guidance is applicable to instrument systems widely used in clinical laboratories and can also be used for manual testing of microbiological identification and antimicrobial susceptibility testing.The aim of this article is to provide advice for the microbial identification system and antimicrobial susceptibility testing system verification process,based on principles of microbiological identification and antimicrobial susceptibility and CLSI M52 guideline.

Sequence-based identification of microbial contaminants in non-parenteral products

ABSTRACT Phenotypic profiles for microbial identification are unusual for rare, slow-growing and fastidious microorganisms. In the last decade, as a result of the widespread use of PCR and DNA sequencing, 16S rRNA sequencing has played a pivotal role in the accurate identification of microorganisms and the discovery of novel isolates in microbiology laboratories. The 16S rRNA region is universally distributed among microorganisms and is species-specific. Accordingly, the aim of our study was the genotypic identification of microorganisms isolated from non-parenteral pharmaceutical formulations. DNA was separated from five isolates obtained from the formulations. The target regions of the rRNA genes were amplified by PCR and sequenced using suitable primers. The sequence data were analyzed and aligned in the order of increasing genetic distance to relevant sequences against a library database to achieve an identity match. The DNA sequences of the phylogenetic tree results confirmed the identity of the isolates as Bacillus tequilensis, B. subtilis, Staphylococcus haemolyticus and B. amyloliqueficians. It can be concluded that 16S rRNA sequence-based identification reduces the time by circumventing biochemical tests and also increases specificity and accuracy.

RESUMO Os perfis fenotípicos para identificação microbiana são incomuns para micro-organismos raros, de crescimento lento e exigentes. Na última década, em resultado do uso generalizado de PCR e sequenciação de DNA, a sequenciação do rRNA 16S tem desempenhado papel crucial na identificação precisa do micro-organismo e a descoberta de novos isolados em laboratórios de microbiologia. A região de rRNA 16S é universalmente distribuída entre micro-organismos e é espécie-específica. A genotipagem foi realizada sobre os organismos isolados a partir de formulações farmacêuticas não parenterais. O DNA foi separado dos cinco isolados obtidos a partir das formulações. As regiões alvo dos genes de rRNA foram amplificados por PCR e sequenciados utilizando os iniciadores adequados. Os dados dos sequência foram analisados e alinhados na ordem crescente de distância genética de sequências relevantes contra biblioteca de dados para obter a identidade. A sequência de DNA de árvores filogenéticas confirma a identidade dos isolados como Bacillus-tequilensis, B. subtilis, Staphylococcus haemolyticus e B. amyloliqueficians. Pode-se concluir identificação baseada na sequência do rRNA 16S reduz o tempo por evitar testes bioquímicos e também aumenta a especificidade e a precisão.

Psychrotrophic bacteria in milk: How much do we really know?

The occurrence of psychrotrophic bacteria in raw milk is studied worldwide due to the difficulties associated with controlling their growth during cold storage and the consequent negative effects upon fluid milk or dairy products. Among the psychrotrophic bacteria, the genus Pseudomonas (represented primarily by P. fluorescens) has been highlighted as the cause of numerous defects in dairy products. In light of its perceived predominance, this species has frequently been chosen as a model organism to assess the effects of psychrotrophic bacteria on milk or to evaluate the efficacy of control measures. However, recent findings derived from the application of molecular biological techniques have exposed a number of deficiencies in our knowledge of the biology of milk-associated psychrotrophs. Furthermore, it has been revealed that microbe to microbe communication plays a significant role in determining both the identities and the extent to which different groups of microbes develop during cold storage. The application of molecular identification methods has exposed errors in the classification of members of the genus Pseudomonas isolated from cold stored milk and has stimulated a reevaluation of the presumed status of P. fluorescens as the predominant milk-associated psychrotrophic species. This article presents a succinct review of data from studies on psychrotrophic bacteria in milk, some of which contest established theories in relation to the microbiology of cold stored raw milk, and poses the question: how much do we really know?.

Comparison of Two Kinds of Automated Microbial Identification System Used in the Identification of Brucella / 现代检验医学杂志

Objective To compare Vitek2 Compact and Walkaway 40 in the identification of Brucella.Methods Used Vitek2 Compact and Walkaway 40 automated microbial identification system to identify clinical isolates and compared with the de-tection of 16S rRNA gene sequences analysis.Results The clinical isolates was identified as Bergeyella zoohelcum or Moraxella by Walkaway 40 and as Brucella melitensis by Vitek2 Compact.16S RNA sequence analysis of the isolate,the se-quence was identical to the sequences of 16S rRNA of Brucella,which excluded the possibility of B.zoohelam and Moraxel-la .Determined that the isolate was B.melitensis.Conclusion Vitek 2 Compact can accurately identified Brucella.Use molec-ular methods to corroborate when the isolates was identified as Brucella by Vitek 2 Compact,this method can greatly im-prove the detection rate of brucellosis and reduce the possibility of misdiagnosis.Walkaway 40 cannot accurately identified Brucella,Misidentification of Brucella can result in wrong treatment of the patient and let the staff in the risk of laboratory-acquired infection.Recommend laboratory should be cautious reporting in the identified B.zoohelam or Moraxella by Walk-away 40 and use Vitek2 Compact or molecular methods for review.

MALDI-TOF MS in the clinical microbiology laboratory / MALDI-TOF MS no laboratório de microbiologia clínica

Traditional methods for microbial identification are often very laborious and time consuming. A new mass spectrometry based technique, matrix-assisted laser desorption ionization-time of flight (MALDI-TOF), has been described as a rapid, practical and low-cost method for this purpose. In this article, primary and possible future applications of this tool are briefly discussed.

Os métodos tradicionais para identificação de microrganismos no laboratório clínico muitas vezes são trabalhosos e demorados. Uma nova metodologia, com base em espectrometria de massas, a matrix-assisted laser desorption ionization-time of flight (MALDI-TOF), é extremamente promissora para utilização na rotina microbiológica, sendo rápida, prática e pouco custosa. Neste artigo, são expostas, de forma breve, as principais aplicações atuais do método, assim como as perspectivas futuras.

Identification and Distribution of Hydantoinase-and Carbamoylase-producing Bacteria / 微生物学通报

The isolated 24 strains-producing hydantoinase & carbamoylase were first identified by Biolog microbial identification system and 16S rDNA sequence analysis.The results suggested that the hydantoinase & carbamoyalse-producing bacteria belonged to Bacillus,Geobacillus,Brevibacillus,Aneurinibacillus,Microbacterium,Pseudomonas,Kurthia and Empedobacter,and so on.Especially,Kurthia and Empedobacter were new hydantoinase & carbamoylase-producing genera.Furthuremore,it was found that D-hydatoinase & carbamoyalse-producing bacteria belonged to Pseudomonas and Agrobacterium,while most of L-hydantoinase & carbamoyalse-producing bacterial belonged to Bacillus,Geobacillus and Microbacterium.The distribution feature of D-hydantoinase & carbamoyalse-producing bacteria and L-hydantoinase & carbamoyalse-producing bacteria showed some genera tendency.This research work will provide the biomaterial of different hydantoinase and carbamoylase and contribute to study the structure and function,molecular evolution of the two enzymes.