Incidence Of Listeria Monocytogenes Research Articles

Incidence of Listeria monocytogenes, Staphylococcus aureus and Escherichia coli in Fresh White Cheese in Gaza City Markets

Incidence of Listeria monocytogenes, Staphylococcus aureus and Escherichia coli in Fresh White Cheese in Gaza City Markets

A retrospective review of Listeria monocytogenes infection at Tygerberg Children’s Hospital, Cape Town, South Africa, from 2006 to 2016: Is empirical ampicillin still indicated after the first month of life?

Ampicillin to treat Listeria monocytogenes (LM) infection is empirically added to the treatment of infants (<3 months) with suspected sepsis or meningitis. In view of limited LM cases, the paucity of South African (SA) data and an ampicillin shortage, our objective was to describe the occurrence of LM infections at Tygerberg Hospital (TBH), Cape Town, with the aim of rationalising the paediatric antibiotic policy. An 11-year (2006 - 2016) retrospective descriptive study of children (<13 years) from TBH and referral hospitals with a positive blood or cerebrospinal fluid (CSF) culture for LM was conducted. Of 26 children with positive cultures for LM, 23 (88.5%) were <3 months of age; all were <10 days old. Approximately half (56.5%, 13/23) were born at or referred to TBH. Presentation was on the day of delivery in 46.2% (6/13), 92.3% were admitted to the neonatal intensive care unit (NICU), and 61.5% (8/13) died. Neonates treated at peripheral hospitals were statistically more likely than those treated at TBH to have a CSF culture obtained (90.0% v. 30.8%; p=0.005), and had higher platelet counts (239 × 109/L v. 107 × 109/L; p=0.004), lower C-reactive protein levels (64 mg/L v. 137 mg/L; p=0.013) and a lower mortality rate (0% v. 61.5%; p=0.002). The incidence of LM at TBH was 0.04/1 000 live births and 2.3/1 000 NICU admissions. As in other countries, the local neonatal LM incidence is low. Neonates present in the first week of life with severe disease and a high mortality rate. These data support a change in antibiotic policy, in keeping with international guidelines, limiting empirical ampicillin prescription to infants <1 month of age.

Incidence of Listeria monocytogenes in Meat Product Samples by Real-Time PCR

The aim of this study was to trace a contamination of meat products with Listeria monocytogenes. Step One real time Polymerase Chain Reaction (PCR) was used. We used the PrepSEQ Rapid Spin Sample Preparation Kit for isolation of DNA and MicroSEQ® Listeria monocytogenes Detection Kit for the real-time PCR performance. We found out the strains of Listeria monocytogenes in hundred samples of meat products with no incubation. There was Internal Positive Control (IPC) in 40 samples. Our results showed that the real time PCR assay tested in this study might detect Listeria monocytogenes in meat product samples with no incubation sensitively.

Application of real-time PCR to detect Listeria monocytogenes in a mussel processing industry: Impact on control

Real-Time PCR is a very powerful tool with multiple applications in food microbiology, being pathogen detection the most important for food safety. In early January 2013 an increase in the incidence of Listeria monocytogenes was observed in a mussel-processing facility in the north-west of Spain. Then, a previously in-house validated qPCR method was applied to detect the contamination origin in the processing line. By the end of the same month a total of 62 samples from different spots in the processing plant were analyzed, obtaining 25 positive results by qPCR. All the isolates, identified as L. monocytogenes, presented the same biochemical profile and belonged to the same molecular typing group (Group 3). After the identification and elimination of the contamination source, 25 additional samples were analyzed over the following nine months, without any positive sample. Results obtained showed that the qPCR method is a suitable technique to identify the exact source of contamination that could appear in food processing plants, saving time respect to traditional culture methods.

Incidence of Listeria monocytogenes and Listeria spp. in a Small-Scale Mushroom Production Facility

Listeria monocytogenes is a foodborne pathogen of significant concern to the agricultural and food processing industry because of its ability to grow and persist in cool and moist environments and its association with listeriosis, a disease with a very high mortality rate. Although there have been no listeriosis outbreaks attributed to fresh mushrooms in the United States, retail surveys and recalls are evidence that L. monocytogenes contamination of mushrooms (Agaricus bisporus) can occur. The objective of this study was to determine the prevalence of Listeria spp., including L. monocytogenes, in a small-scale mushroom production facility on the campus of the Pennsylvania State University in the United States. Of 184 samples taken from five production zones within the facility, 29 (15.8%) samples were positive for Listeria spp. Among the Listeria spp. isolates, L. innocua was most prevalent (10.3%) followed by L. welshimeri (3.3%), L. monocytogenes (1.6%), and L. grayi (0.5%). L. monocytogenes was recovered only from the phase I raw material composting area. Isolates of L. monocytogenes were confirmed and serotyped by multiplex PCR. The epidemiological relatedness of the three L. monocytogenes isolates to those serotypes or lineages frequently encountered in listeriosis infections was determined by multi-virulence-locus sequence typing using six virulence genes, namely, prfA, inlB, inlC, dal, clpP, and lisR. The phylogenetic positions of the three isolates in the dendrogram prepared with data from other isolates of L. monocytogenes showed that all isolates were grouped with serotype 4a, lineage IIIA. To date, this serotype has rarely been reported in foodborne disease outbreaks.

Incidence of Listeria monocytogenes and Other Bacteria in Spontaneous Abortion Cases in Jos.

The involvement of Listeria monocytogenes in spontaneous abortion in Jos was investigated. One hundred blood and 100 placenta samples were collected from spontaneous abortion patients in Jos. The samples were inoculated first into Listeria enrichment broth. Incubation was at 37o C, followed by cold enrichment at OO C for samples that did not yield any growth at 370 C. Further sub- inoculations were made on Listeria selective agar. In addition, parallel inoculations were also made on blood, chocolate and MacConkey agar media using standard bacteriological methods. Listeria-like organisms were subjected to biochemical and serological investigations using type 1a, 4b and polyvalent sera supplied by Difco laboratories (Detroit, Michigan). Enterococcus faecalis, Proteus mirabilis, Escherichia coli , and L. monocytogenes were some of the bacteria isolated. They had the following percentage frequencies of occurrence: 40.20, 13.80, 11.50 and 8.04 respectively. L. monocytogenes contributed to the burden of spontaneous abortion in Jos and environs. Keywords: Spontaneous abortion, Listeria, isolation, incidence Nig J. Biotech . Vol. 25 (2013) 18-22

Detection of Listeria monocytogenes by the polymerase chain reaction (PCR) technique in samples of raw bovine milk

Considering the possible incidence of Listeria monocytogenes in raw foods and their pathogenicity and health risk, this study aimed to compare techniques for extraction of bacterial DNA from milk samples and investigate the presence of L. monocytogenes by Polymerase Chain Reaction (PCR) in raw milk. We tested four different extraction protocols (generally identified: A, B, C, and D) for isolation of bacterial DNA directly from milk. In all of them was obtained identifying the product of 702 bp (base pairs) corresponding to the listeriolysin gene from L. monocytogenes . The protocol B containing proteinase K and phenol buffered, was chosen for the extraction of DNA from milk samples from eight dairy farms within the RS. The subsequent PCR amplification with DNA obtained by the protocol B allowed the identification of L. monocytogenes from 10 3 CFU/mL. None of the samples was positive for the producer L. monocytogenes by PCR or by conventional microbiological analysis. With this study it is concluded that the tested protocols, the protocol B was more effective for the detection of L. monocytogenes by PCR. Moreover, for the samples of the producers, the result PCR technique was obtained in a shorter time than conventional analysis of L. monocytogenes , which may allow earlier treatment of infected animals and thus avoid losses to the producer.

Incidence of Listeria monocytogenes in cheese manufacturing plants from the northeast region of São Paulo, Brazil.

The incidence of Listeria monocytogenes in three cheese manufacturing plants from the northeastern region of São Paulo, Brazil, was evaluated from October 2008 to September 2009. L. monocytogenes was found in samples from two plants, at percentages of 13.3% (n = 128) and 9.6% (n = 114). Samples of raw and pasteurized milk, water, and Minas Frescal cheese were negative for L. monocytogenes, although the pathogen was isolated from the surface of Prato cheese and in brine from one of the plants evaluated. L. monocytogenes was also isolated from different sites of the facilities, mainly in non-food contact surfaces such as drains, floors, and platforms. Serotype 4b was the most predominant in the plants studied. The results of this study indicate the need for control strategies to prevent the dispersion of L. monocytogenes in the environment of cheese manufacturing plants.

Listeria monocytogenesin refrigerated and frozen chicken parts

The incidence of Listeria monocytogenes in refrigerated and frozen chicken parts was investigated, using the Mini-Vidas™ system (bioMerieux). Two hundred and eigthy chicken parts were tested: 40 skin samples from the breast and leg, 120 samples from refrigerated wings, breasts and legs and 120 samples from frozen wings, breasts and legs (40 of each). The 219 samples tested positive (78.21%). The parts with the highest incidence were frozen breasts (100%) and wings (95%). In frozen legs, the values were lower (60%). In refrigerated parts, the incidence was higher in breasts (85%) and in wings (80%). In legs samples, similarly to the frozen ones, the incidence was lower (50%). In the skin of the breasts and legs, the incidence was 77.50%. Statistical evaluation demonstrated that there are no differences between frozen breasts and wings but there are differences between similar refrigerated parts. The refrigerated and frozen legs are the only parts that are statistically equal. The percentages that were dete...

Incidence of Listeria monocytogenes and Escherichia coli O157:H7 in two Kasar Cheese processing environments

This study was designed to determine the presences of two environmental pathogens in two dairy factories in Sakarya, Turkey. A total of 264 environmental samples, raw milk and cheese samples were taken at four different seasons. According to the results, Listeria monocytogenes or Escherichia coli O157:H7 was isolated from 26 or 2.7% of the samples collected from both factories, respectively. None of the cheese or curd samples were found to be positive for Listeria or E. coli O157:H7. However, 50% of raw milk samples contained Listeria innocua. Listeria was mostly isolated from the swap samples taken from the drains or the floors in processing or packaging areas. However, E. coli was also isolated from the swap samples taken from the workers’ hands and gloves as well as the drains and the floor. Only one raw milk sample contained E. coli O157:H7. A higher prevalence of both pathogens was observed in the summer months than in the other months.

Incidence of Listeria monocytogenes in beef, pork, raw-dried and raw-smoked sausages in Bulgaria

For a 5-years period (2002–2007) 786 samples (505 samples of beef, pork, minced beef, minced pork and 281 samples of raw-dry and raw-smoked sausages) were analyzed. From beef and pork 39 strains Listeria monocytogenes (7.7%), three strains Listeria ivanovii (0.6%), 23 strains Listeria innocua (4.6%) and four strains Listeria welshimeri (0.8%) were obtained. L. monocytogenes were isolated in 28 samples (10.0%), L. ivanovii, L. innocua and L. welshimeri – in 0.7%, 4.3% and 0.7%, respectively, from investigated raw-dried and raw-smoked sausages.

Incidence and growth of Listeria monocytogenes in persimmon (Diospyros kaki) fruit

The incidence of Listeria monocytogenes on persimmon ( Diospyros kaki) surface of ‘Fuyu’ and ‘Rama Forte’ was evaluated during a 5-month-period (from March to July) of two seasons periods (years 2005 and 2006). The fruits were collected in wholesale and street markets and retail in Sao Paulo and Campinas City, Brazil. A total of 582 fruits were analyzed using the Bax® System which is based on the Polymerase Chain Reaction. The ability of this pathogen to grow on the peel and pulp of the two persimmon varieties was also verified at different incubation periods at the temperatures of 10, 20 and 30 °C. The growth parameters were obtained by modeling the experimental data using the Gompertz function. The incidence survey showed the absence of L. monocytogenes. The growth curves showed that L. monocytogenes can grow on the peel as well as in the pulp of the two persimmon varieties studied incubated at 10, 20 and 30 °C and that low temperatures can reduce the generation rate but does not inhibit its growth.

Antibiotic resistant pattern of environmental isolates of Listeria monocytogenes from Ado-Ekiti, Nigeria

Incidence of Listeria monocytogenes in cow manure, agricultural soil, and common vegetables sold in major markets in Ado-Ekiti, Nigeria was determined. Antibiotic resistant pattern of the isolates was examined by paper disk assay. A total of 196 environmental samples were cultured on a selective medium out of which 153 (78.1%) were positive for L. monocytogenes. Erythromycin was the most effective antibiotic against the isolates with the least resistance (28.1%) while chloramphenicol proved to be least effective with resistant of 52.29%. The multiple-antibiotic resistant pattern of the isolates showed augumentin/amoxicillin (33.3%), lugumentin/erythromycin (24.18%), and cotrimoxazole/ chloramphenicol/amoxicillin (28.8%) to be most prominent. The least value was observed in cloxacilin/cotrimoxazole/gentamycin with 15.34%. The modal values of the Minimum Inhibitory Concentrations (MICs) of the antibiotics to the isolates range between 4.0 and >16.0 ig/ml. cotrimoxazole and gentamicin recorded the highest MIC compared with other antibiotics.

English

Incidence of Listeria monocytogenes in cow manure, agricultural soil, and common vegetables sold in major markets in Ado-Ekiti, Nigeria was determined. Antibiotic resistant pattern of the isolates was examined by paper disk assay. A total of 196 environmental samples were cultured on a selective medium out of which 153 (78.1%) were positive for L. monocytogenes. Erythromycin was the most effective antibiotic against the isolates with the least resistance (28.1%) while chloramphenicol proved to be least effective with resistant of 52.29%. The multiple-antibiotic resistant pattern of the isolates showed augumentin/amoxicillin (33.3%), augumentin/erythromycin (24.18%), and cotrimoxazole/ chloramphenicol/amoxicillin (28.8%) to be most prominent. The least value was observed in cloxacilin/cotrimoxazole/gentamycin with 15.34%. The modal values of the Minimum Inhibitory Concen-trations (MICs) of the antibiotics to the isolates range between 4.0 and >16.0 µg/ml. cotrimoxazole and gentamicin recorded the highest MIC compared with other antibiotics. Key words: Listeria monocytogenes, vegetable, cow dung, antibiotic resistance, environmental isolates.

辛子明太子における<i>Listeria monocytogenes</i> の汚染実態と食品添加物による本菌の制御モデル実験

辛子明太子におけるL. monocytogenes の汚染実態調査を行うとともに, 辛子明太子の製造モデル実験を行い, 添加物製剤などを用いて本菌の制御方法を検討した.辛子明太子144検体中16検体 (11.1%) にL. monocytogenes の汚染が認められたが, 汚染菌量は非常に低いレベルであり, 約80%の検体が1/g未満であり, 100/gを超える検体はなかった. 辛子明太子は低温処理中でのL. monocytogenes 増殖の可能性が低い食品に該当するため, 今回の実態調査で判明した汚染菌量は, 健康人にとっては低リスクな範囲であると考えられた.しかし, 取扱いの不備によってL. monocytogenes の濃厚な汚染が生じた原卵および塩たらこなどの原材料は, 調味液の組成によっては製造工程で本菌が減少しない場合がある. そこで, そのリスクを低減させる目的で, 通常の製造法よりawを0.97と高めに設定した辛子明太子の製造モデル実験により, 食品添加物5製剤とナイシンの計6剤についてL. monocytogenes に対する制御効果を調べた. L. monocytogenes の菌数の減少に優れた効果を示したものは, 2種類の酢酸ナトリウム製剤とナイシンであり, これら3剤のいずれかを塩たらこの塩蔵工程や辛子明太子の調味工程で添加すれば, L. monocytogenes によるリスクを低減できるものと考えられた.

Isolation and Pulsed-Field Gel Electrophoresis Typing of Listeria monocytogenes from Modified Atmosphere Packaged Fresh-Cut Vegetables Collected in Ireland

The incidence of Listeria monocytogenes in modified atmosphere packaged fresh-cut fruits and vegetables from chill cabinets of a supermarket in Ireland was investigated over a 2-year period. Overall, 9.58% of fresh-cut produce was contaminated with Listeria spp. Various species of Listeria were isolated from samples, including L. monocytogenes, L. seeligeri, L. innocua, L. welshimeri, and L. ivanovii. No fruit samples contained detectable L. monocytogenes. Overall, a total of 21 L. monocytogenes isolates (2.9% of samples) were recovered from a range of products, including dry coleslaw mix (80% shredded cabbage and 20% shredded carrot), bean sprouts, and leafy vegetables such iceberg, romaine, and radicchio lettuce and mixed salad leaves (curly endive, escarole, and radicchio leaves). Dry coleslaw mix appeared to have the highest incidence of Listeria contamination (20%) compared with other products. Listeria contamination was more frequent (P < 0.05) during the summer and autumn months than during the winter and spring months. The 21 L. monocytogenes isolates were subsequently subtyped by genomic macrorestriction techniques using ApaI with pulsed-field gel electrophoresis (PFGE). PFGE of digested DNA produced bands of 79 to 518 kb. Four PFGE profiles were identified, and approximately 50% of the isolates were associated with profile 1. This study indicates that fresh-cut vegetables packaged under a modified atmosphere can support growth of numerous species of Listeria, including L. monocytogenes.

Occurrence of foodborne pathogenic bacteria in retail prepackaged portions of marine fish in Spain

To survey the presence of indigenous and nonindigenous foodborne bacterial pathogens in displayed prepacked portions of fresh marine fish. A survey of 50 different samples of fresh marine fish (conger, swordfish, sole, grouper and whiting) was conducted over a period of 5 months. Trays of fillets and steaks were obtained at retail level and tested for foodborne bacterial pathogens. Vibrio cholerae and Salmonella were not detected. Two samples (4%) yielded Vibrio strains carrying a DNA fragment specific for Vibrio parahaemolyticus, but resulted negative to PCR amplification of the virulence-related tdh gene. Levels of motile Aeromonas ranging from 2.29 to 7.20 log CFU g(-1) were found in 31 (62%) samples. All fish portions were positive for the Aeromonas hlyA gene and 38 for both aerA and hlyA genes, which may contribute to diarrhoea-related virulence. The incidence of Listeria monocytogenes was 10%. Levels of Staphylococcus aureus lower than 2 log CFU g(-1) were found in 15 (30%) samples. Numbers of presumptive Clostridium perfringens ranging from 1.82 +/- 0.22 to 4.26 +/- 1.25 log CFU g(-1) were detected in 42 (84%) samples. Edwardsiella tarda was detected in two samples of grouper fillets. Displayed portions of raw fish carried bacteria that can cause foodborne disease. The risk posed by fresh fish when properly cooked is low, but high when destined to be consumed raw, undercooked or very lightly processed. This study revealed that raw fish sold in Spain could be a source of foodborne bacterial pathogens. Improvements in handling and processing are needed to minimize the prevalence of pathogenic bacteria.

Incidence of Listeria monocytogenes in Raw Seafood Products in Japanese Retail Stores

The incidence of Listeria monocytogenes in raw fish, shellfish, and fish roe was investigated in seafood products collected from randomly selected retail stores in and around Tokyo, Japan. Of the 10 samples of 208 examined found positive for L. monocytogenes by mini-VIDAS LMO, seven were fish roe (cod, salmon) and three were minced tuna. Three serotypes (1/2a, 1/2b, 3b) were detected among the isolated strains; serotype 1/2a was predominant (8 of 10).

Detection, Enumeration, and RAPD Analysis of Listeria monocytogenes Isolates in Fish Derived fromRetail Outlets in WesternMassachusetts

Fish were sampled over a 24-month period from two major supermarket retail outlets in Hadley, Massachusetts, USA, designated A and B, for the incidence of Listeria monocytogenes and numbers of the organism present per 100 g of tissue. Fifteen species of fish were represented. Seventy-four samples out of a total of 320 were confirmed by PCR as yielding L. monocytogenes. From retail source A, a total of 171 samples yielded 59 (34.5%) that were positive for the presence of L. monocytogenes. In contrast, from retail source B, a total of 149 samples yielded 15 (10.0%) that were positive. Only six samples (3.5%) from retail source A had MPN counts of L. monocytogenes in the range of 100 to 1,000 per 1,000 g. Only two samples (1.3%) from retail source B had counts of L. monocytogenes from 100 to 1,000 per 100 g. A total of 221 strains of L. monocytogenes were derived from the MPN cultures, 164 from retail source A, and 57 from retail source B. All 221 strains were subjected to RAPD analysis using three random primers. Primer LMPB1 yielded 21 RAPD profiles, primer LMPB4 yielded 19 profiles, and primer HLWL74 yielded 26 profiles. A total of 55 composite profiles were identified by combining the profiles derived from the three primers. Source A yielded 50 composite RAPD profiles, whereas source B yielded only ten composite profiles. In addition, 27 of the 55 composite profiles were derived from individual isolates and RAPD types 11 and 18 included 49 and 27 isolates respectively. Fish from retail source A clearly harbored far more RAPD types than did source B. The results clearly indicated that two major retail sources in close geographic proximity can vary considerably with respect to the incidence and numbers of L. monocytogenes present on the fish tissue. It was not possible to determine whether the processors furnishing fish to retail outlet A or the supermarket itself was responsible for the notably higher incidence and numbers of L. monocytogenes on fish from retail source A compared to fish from retail source B.

Incidence of Listeria monocytogenes in different food products commercialized in Portugal

Several types of food products on sale in Portugal, were examined for the presence of Listeria monocytogenes. Secondary enrichments, in Fraser broth, were analysed by the mini-Vidas LMO, enzyme-linked fluorescent immunoassay technique. Positive samples were confirmed by isolation on Oxford and PALCAM selective agars followed by biochemical characterization. Of 1035 samples, 72 (7.0%) were positive for L. monocytogenes, the majority being from raw products (milk, meat, fish, flour) although some heat-processed or fermented foods (ready-to-eat) were also positive. In Portugal, a predilection for fresh cheese was indicated as a potential risk for consumers.