Detection of psychrophilic and psychrotolerantClostridiumspp. in chilled fresh vacuum-packed meat using different PCR methods

Abstract

Since 1989, blown pack spoilage has been recognized as a special form of spoilage in vacuum-packed raw and cooked beef. However, only limited information concerning the occurrences of bacteria causing blown pack spoilage on chilled fresh meat is available. In this study, a total of 63 beef and 33 lamb commercially available samples from different countries and without any signs of spoilage were examined for contamination with psychrophilic and psychrotolerant Clostridium spp. using different PCR systems. In total, 34.4% of the chilled fresh vacuum-packed meats were PCR positive. A higher number of lamb samples were identified as PCR positive compared with beef. A geographical relationship between positive results and the origin of the samples could not be determined. PCR system described by Brightwell and Clemens (Development and validation of a real-time PCR assay specific for Clostridium estertheticum and C. estertheticum-like psychrotolerant bacteria. Meat Sci 2012;92:697-703) gave the highest number of positive detections compared with the Broda, Boerema and Bell PCR system (PCR detection of psychrophilic Clostridium spp. causing 'blown pack' spoilage of vacuum-packed chilled meats. J Appl Microbiol 2003;94:515-22). Eight clostridia isolates from two German beef and four Welsh lamb samples were isolated overall. Three of these clostridia isolates were identified as Clostridium estertheticum whereas five clostridia isolates remain unidentified. The study shows that psychrophilic and psychrotolerant Clostridium spp. are more prevalent in retail samples than previously suspected.

A case of ‘blown pack’ spoilage of vacuum‐packaged pork likely associated with Clostridium estertheticum in Canada

“…The isolated C. estertheticum strain from BPS pork showed β‐haemolysis on CBA. In the studies of Dorn‐In et al () and Bonke et al (), all strains of C. estertheticum showed β‐haemolysis on blood agar. Yang et al () showed that both C. estertheticum sub spp.…”

“…(2018) and Bonke et al (2016), all strains of C. estertheticum showed b-haemolysis on blood agar. Yang et al (2010b) showed that both C. estertheticum sub spp.…”

“…Some of the minor Clostridium OTUs may have been amplified by the real‐time PCR method due to the very high similarities among the 16S rRNA genes of some psychrotrophic clostridia. This, along with the findings of the minimum number of C. estertheticum required for (Yang et al ) and the impact of background microflora on BPS development (Yang et al ), may explain the detection of C. estertheticum in BPS negative samples (Bonke et al ). 16S rRNA gene amplicon sequence analysis also showed that both packages of pork had a substantial fraction of LAB including Lactobacillus , Carnobacterium and Lactococcus, which is in agreement with previous findings that LAB are often predominant on VP meats (Doulgeraki et al ; Youssef et al ).…”

IDENTIFICAÇÃO DE PONTOS DE CONTAMINAÇÃO POR Clostridium estertheticum EM AMBIENTES MATADOUROS FRIGORÍFICOS

“…O C. estertheticum ao contrário de outras bactérias do mesmo gênero, não produz toxinas sendo, porém, seus esporos encontrados em embalagens a vácuo resistindo ao pH normal da carne durante quatro semanas (COLLINS et al 1992, HELPS et al 1999, BRODA et al 2002, ADAM et al, 2013. Devido a dificuldades de isolamento e cultivo de C. estertheticum em meio de cultura, a forma mais segura de detecção do agente caracteriza-se pela extração do DNA seguido pelo uso de técnicas moleculares (BONKE et al, 2016).…”

“…Entretanto, difere bastante com o resultado encontrado por BONKE et al (2016), 34,4%. A diferença na positividade entre os resultados comparados é devida, provavelmente, à melhoria dos procedimentos no processo de higienização, os chamados sistemas de: "Boas Práticas de Fabricação" (BPF) e "Análise de Perigos e Pontos Críticos de Controle" (APPCC) que foram incorporados à rotina de limpeza e sanitização após a obtenção dos primeiros resultados.…”