2019年上海市餐饮生食肉制品及相关产品中细菌污染调查分析

目的 了解上海市各餐饮企业生食肉制品微生物污染状况,为该类样品食品安全监督提供科学依据。方法 采用国家标准规定的检测方法,2019年从上海市餐饮企业抽取共计198份生食肉制品及其相关产品进行了卫生指示菌和常见食源性致病菌检测,并用SPSS 16.0软件对测定结果进行分析。结果 从卫生指示菌看,不同样品中,生食肉制品成品及其原辅料菌落总数≥100 000 CFU/g占比2.06%(2/97),大肠菌群超过100 CFU/g占比5.15%(5/97),大肠埃希菌检出率为2.06%(2/97),其中牛肉原料样品检出率为11.11%(2/18),定量均为10 CFU/g；加工过程环节检测中,大肠菌群检出率为12.87%(13/101),其中加工器具大肠菌群检出率为20.83%(10/48)高于餐饮具样品的5.66%(3/53),差异有统计学意义(χ²=12.678,P＜0.05)。从食源性致病菌检测情况看,牛肉原料及成品沙门菌检出率均为5.56%(1/18),其余样品均未检出食源性致病菌。结论 2019年上海市餐饮生食肉制品成品、原料卫生指示菌和沙门菌的检出值得关注,应重视与食品直接接触的加工器具的卫生监督。     

2015~2017年广州市某食品厂低温肉灌肠生产加工过程微生物污染状况及风险分析

目的 了解低温肉灌肠生产加工过程中主要食源性致病菌的污染状况, 分析生产加工过程存在的微生物污染风险。方法 采集2015～2017年广州市某食品厂低温肉灌肠生产加工过程不同环节样品362份, 按食品安全国家标准规定的检测方法对菌落总数、大肠菌群、沙门氏菌、金黄色葡萄球菌和单核细胞增生李斯特氏菌进行检测, 并对结果进行分析。结果 生产加工过程采集的样品沙门氏菌、金黄色葡萄球菌和单核细胞增生李斯特氏菌检出率分别为1.10%(4/362)、0.55%(2/362)和25.97%(94/362)。原辅料、中间产品、成品和终产品单核细胞增生李斯特氏菌检出率分别为48.00%、39.13%、20.00%和0.00%, 差异有统计学意义(χ2=22.57, P<0.05)。结论 低温肉灌肠生产加工过程存在微生物污染风险, 以单核细胞增生李斯特氏菌污染风险最高, 二次杀菌可有效降低低温肉灌肠终产品微生物污染。     

南京市某食品厂酱卤熟肉制品生产加工过程微生物污染状况分析

目的了解南京市某食品厂酱卤熟肉制品加工过程中微生物污染状况及分布情况。方法 2016—2017年在南京市某食品厂采集生产加工过程中食品样品120份(原辅料60份、中间产品28份、成品24份、终产品8份)、环境样品204份、空气样品58份和生产用水14份,共396份,按照GB 4789食品微生物学检验系列标准和GB/T 16294—2010《医药工业洁净室(区)沉降菌的测试方法》对卫生指示菌和主要食源性致病菌进行检测,并对沙门菌进行血清型鉴定。结果在食品样品和环境样品中,李斯特菌检出率为7.4%(24/324),金黄色葡萄球菌检出率为2.6%(5/196),沙门菌检出率为1.9%(6/324);其中李斯特菌有2株单核细胞增生李斯特菌,其他以格氏李斯特菌和伊氏李斯特菌为主;沙门菌经血清学分型共4种血清型,分别为肠炎沙门菌(2株)、鼠伤寒沙门菌(2株)、依桑吉沙门菌(1株)和亚利桑那沙门菌(1株)。在原辅料、中间产品以及人员、仪器设备、清洁工具中均有致病菌检出,但成品和终产品中未检出致病菌。结论酱卤熟肉制品生产过程原辅料和环境中均存在多种致病菌污染。     

江苏省徐州市市售发酵与非发酵豆制品微生物污染调查

目的 调查江苏省徐州市市售豆制品微生物污染情况。方法 采集发酵、非发酵豆制品86份, 按照GB 4789进行大肠菌群、菌落总数(非发酵豆制品)、蜡样芽胞杆菌、金黄色葡萄球菌的定量和单核细胞增生李斯特氏菌、沙门氏菌的定性检测。结果 大肠菌群检出率为34.88%, 蜡样芽胞杆菌为12.79%, 金黄色葡萄球菌为1.16%, 其余致病菌均未检出。非发酵豆制品中大肠菌群检出率为65.91%, 计数>103 CFU/g占52.27%, 散装较预包装样品检出率高, 差异有显著意义(P<0.05); 菌落总数>105 CFU/g占75.00%; 蜡样芽胞杆菌检出率为6.82%, 104 CFU/g(均<105 CFU/g)占4.55%; 金黄色葡萄球菌检出率为2.27%。发酵类豆制品中大肠菌群检出率为2.38%, 蜡样芽胞杆菌为19.05%, 104 CFU/g占7.14%(均<105 CFU/g); 预包装、散装样品蜡样芽胞杆菌检出率差异无显著意义(P>0.05)。发酵、非发酵豆制品中大肠菌群检出率差异均有显著意义(P<0.05); 发酵豆制品合格率为97.62%, 非发酵豆制品合格率为11.36%, 差异有显著意义(P<0.05)。结论 徐州市豆制品中非发酵类卫生指标菌污染较为严重, 应加强卫生监督。     

北京市餐饮业食用冰块微生物污染水平调查

评估北京市餐饮业食用冰块微生物污染的风险。方法 在北京市场抽检了63份餐饮业食用冰块样品,冰块独立分装在无菌采样袋中,2 h内完成采样到检测的过程。按照国家标准方法检测其中的菌落总数、大肠菌群、沙门菌、志贺菌和金黄色葡萄球菌。结果 63份餐饮业食用冰块样品均未检出沙门菌、志贺菌和金黄色葡萄球菌等致病菌。连锁快餐店和咖啡店食用冰块的菌落总数和大肠菌群等指示菌计数较低,部分饮品甜品店食用冰块菌落总数和大肠菌群较高。结论 检测的食用冰块样品均是安全的。部分饮品甜品店用食用冰块指示菌较高,提示生产过程中可能存在微生物污染,需要严格执行卫生操作规范的程序。     

鸡精调味料加工过程中微生物检测及安全控制

为提高鸡精调味品卫生质量,根据生产工艺特点分别对鸡精生产原辅料、加工流程及主要加工设备进行了微生物检测。食用玉米淀粉和葱姜混合物是鸡精生产原辅料中的主要微生物来源,水分含量是直接影响玉米淀粉微生物污染的主要因素,当水分含量10%时,100 g玉米淀粉大肠菌群70 MPN;葱姜混合物经30%质量分数的食用盐处理后可控制微生物的数量。鸡精生产工序过程中的搅拌后、造粒前后及流化干燥前微生物污染严重,其中搅拌后菌落总数最高,为1.2×104CFU/g,造粒前大肠菌群最高,为167 MPN/100g,搅拌和造粒是鸡精生产过程中的关键控制环节。另外,造粒机筛网及侧槽的菌落总数达到908 CFU/cm2,高于食品车间卫生标准,表明造粒岗位是鸡精生产的一个关键控制点。     

2016—2020年上海市市售即食食品微生物污染状况分析及评价

目的 了解上海市市售即食食品中微生物污染情况,及时发现食品安全隐患,为即食食品风险评估、管理和标准制定提供科学依据。方法 2016-2020 年共采集上海市即食食品20类共10 521份食品样品,对菌落总数、大肠埃希氏菌计数2种卫生指示菌和副溶血性弧菌、金黄色葡萄球菌、致泻大肠埃希氏菌、沙门氏菌、蜡样芽孢杆菌、单核细胞增生李斯特氏菌（以下简称单增李斯特菌）6种食源性致病菌进行定量或定性检验,并分析卫生指示菌和食源性致病菌污染水平及关联性。结果 凉拌米面制品、沙拉、中式凉拌菜的指示菌污染水平较高,菌落总数均值分别为（5.13±1.43）lgCFU/g、（4.56±1.13）lgCFU/g、（4.26±1.75）lgCFU/g;大肠埃希氏菌计数分别为（1.20±1.00）lgCFU/g、（1.47±1.41）lgCFU/g、（1.18±1.06）lgCFU/g。冷锅串串、沙拉、中式凉拌菜、熟肉制品中单增李斯特菌检出率较高,分别为6.27%、3.36%、2.71%、2.69%;副溶血性弧菌仅在生食动物性水产品（3.65%）、中式凉拌菜（2.58%）、熟肉制品（0.42%）中检出;米面制品中蜡样芽孢杆菌（7.51%）显著高于寿司（0.53%）（P<0.05）。菌落总数均值与大肠埃希氏菌计数均值呈极显著正相关（P<0.001）;菌落总数均值与致病菌样品阳性率呈显著正相关（P<0.05）。结论 上海市生食食物、凉拌、夹心等最后一步加工工艺非加热的即食食品,卫生指示菌和致病菌污染水平较高,食源性致病风险较高,应重点防范。固体即食食品菌落总数计数水平与食源性致病菌污染状况存在相关性。     

灌肠类熟肉产品生产环节微生物污染风险评估

根据国家食品安全标准检测灌肠类熟肉制品生产过程各环节环境、原辅料及产品的菌落总数、大肠菌群、亚硫酸盐还原梭状芽胞杆菌、金黄色葡萄球菌、沙门氏菌和单核细胞增生李斯特菌,同时测定致病菌的耐药性。结果显示:原辅料和中间产品受大肠菌群和厌氧亚硫酸盐还原梭状芽孢杆菌的污染较重;生产用水和终产品的卫生状况良好。环境和原辅料中均有致病菌检出,主要为金葡菌和沙门氏菌。分离出的沙门氏菌和金葡菌耐药严重,分别有88.89%的沙门氏菌和85.71%的金葡菌具有多重耐药性。说明灌肠类熟肉制品生产过程极易受到大肠菌群、厌氧亚硫酸盐还原梭状芽孢杆菌、金葡菌和沙门氏菌的污染,生产原辅料是主要的微生物污染来源。     

市售鲜湿米粉菌落总数及大肠菌群数繁殖动态的考察

目的 考察南宁市售不同厂家的鲜湿类米粉的菌落总数、大肠菌群污染状况及后续繁殖动态。方法 按照GB 4789.1-2016《食品安全国家标准 食品微生物学检验 总则》抽样方法, 从餐饮店抽取6批不同厂家的未开封的鲜湿米粉。按照GB 4789.2-2016《食品安全国家标准 食品微生物学检验 菌落总数测定》、GB 4789.3-2016《食品安全国家标准 食品微生物学检验 大肠菌群计数》的检测方法, 分别在0、2、4、8、12、16、24 h对样品的菌落总数及大肠菌群项目进行检测, 在24 h同时取部分样品在沸水中焯1 min后平行检测, 对计数结果进行分析。结果 0 h时, 各样品的菌落总数在3.1×103~6.9×107 CFU/g, 大肠菌群在0~8.5×105 CFU/g。在22 ℃条件放置下, 随着时间推移, 各样品的菌落总数和大肠菌群数仍不断增殖。16 h(即保质期过后), 菌落总数达到7.2×107~1.9×109 CFU/g左右, 繁殖基本趋缓。24 h时, 在沸水中焯1 min后, 所有样品的菌落总数小于1.3×103 CFU/g, 大肠菌群均小于10 CFU/g, 远低于标准规定。结论 22 ℃储藏条件下并不能遏制鲜湿米粉的菌落总数及大肠菌群增殖, 沸水焯1 min可有效降至安全水平。     

肉枣加工过程中细菌群落消长规律

目的:确定导致样品胀袋的关键控制点,加强肉枣加工过程中微生物污染防控。方法:采用微生物传统培养法结合高通量测序手段分析肉枣生产全过程中不同加工工序样品及胀袋样品的微生物变化情况。结果:整体来看,原料中菌落总数较低,其中鸡皮中菌落总数最高达9.10×10⁴ CFU/g,蒸煮后菌落总数下降至30 CFU/g,但真空包装后菌落总数显著上升,说明真空包装工序存在较大污染风险。胀袋样品中微生物增殖明显,菌落总数为1.03×10⁶～3.30×10⁶ CFU/g。肉枣原料中的优势菌属为不动杆菌属(Acinetobacter)、嗜冷杆菌属(Psychrobacter)和假单胞菌属(Pseudomonas)。加工过程中样品的主导菌属为葡萄球菌属(Staphylococcus),灭菌后其相对丰度降至0.02%。而胀袋样品中均以枝芽孢菌属(Virgibacillus)为主,平均相对丰度为99.37%;该属在灌肠工序开始出现,且耐热性较强,灭菌后其相对丰度增加。结论:灌肠和包装工序可能为肉枣加工过程中的关键污染点。     

Recovery of Staphylococcus aureus in Gray Mugil cephalus Roe (Bottarga): Investigation by an Integrated Cultural/Molecular Approach

In the Mediterranean area, salted and dried roe from the gray Mugil cephalus “bottarga” represent a speciality food with great commercial value. Bottarga is currently produced by a traditional handmade process and, the risk of human bacterial contamination during its manufacturing is still unknown; in this perspective the foodborne pathogen Staphylococcus aureus could potentially contaminate this product due to poor sanitation or bad handling during processing. The aim of this work is: to evaluate the contamination level of foodborne pathogens at different product manufacturing stages and, in addition, to describe a fast and realizable method for the rapid detection of S. aureus in bottarga samples in the field. A cultural procedure was initially used to investigate the occurrence of S. aureus and the other main foodborne pathogens in bottarga samples at the different manufacturing stages (from roe to final product). In addition, a molecular approach was used to rapidly determine the presence of total bacteria, S. aureus, and its potential toxigenicity. Of the 194 specimens analyzed, we identified: Clostridium perfringens, Enterococcus spp. and Enterobacteriaceae. However, some samples resulted as being contaminated with S. aureus (4% in roe and 8.7% in the final product). During the bottarga manufacturing process, we observed an increase in pathogen levels (from 10² to 10⁵ CFU/g) in contaminated samples, and entA and entB genotypes were identified. Reconstruction experiments suggest that the fresh roe and the bottarga (not completely dried) could represent a risk for the contamination and growth of pathogen bacteria.     

A field study of the microbiological quality of fresh produce of domestic and Mexican origin

Produce is responsible for an increasingly larger proportion of foodborne disease outbreaks. In particular, the globalization of the food supply may introduce new food safety risks and allow widespread distribution of contaminated food, particularly produce. The objectives of this study were to: (i) compare the overall quality of domestic and Mexican produce throughout the packing process; (ii) examine changes in microbiological quality of both domestic and Mexican produce at each stage of production and processing; and (iii) evaluate the prevalence of select pathogens on fresh produce, including leafy green, herbs, melons, and vegetables. Furthermore, we also sought to characterize the antibiotic resistance profiles of Enterococcus faecium and Enterococcus faecalis strains isolated from fresh produce. A total of 466 produce and matching environmental swab samples was collected from various locations in packing sheds in the southern US from November 2002 through December 2003. These samples were assayed by enumerative tests for total aerobic bacteria (APC), total coliforms, total Enterococcus, and E. coli. Produce samples were also analyzed for the presence of Salmonella, Listeria monocytogenes, Shigella, and E. coli O157:H7. A total of 112 E. faecium and E. faecalis isolates were further screened for antibiotic resistance using a panel of seventeen antibiotics. Overall, the microbiological quality of fresh produce ranged from 4.0 to 7.9 log(10) CFU/g (APC); less than 1.0 log(10) to 4.5 log(10) CFU/g (coliforms); less than 1.0 log(10) to 4.0 log(10) CFU/g (E. coli); and less than 1.0 log(10) to 5.4 log(10) CFU/g (Enterococcus). No Salmonella, Shigella, or E. coli O157:H7 were detected from the 466 25-g produce samples tested. However, three domestic cabbage samples were found to be positive for L. monocytogenes. Of the Enterococcus isolates, E. faecium had a higher degree of resistance to antibiotics in general, while Enterococcus spp. isolated from Mexican produce had a higher degree of antibiotic resistance when compared to strains isolated from produce samples of domestic origin. Despite increased attention to the role of imported produce in foodborne disease, this study does not support the assumption that domestic produce is of higher microbial quality than Mexican produce.     

Bacterial contamination of ready-to-eat foods and fresh products in retail shops and food factories.

Raw vegetables cut for salad, cooked salad, cooked rice, boiled noodles, bean curd, and cooked Japanese foods were purchased in 27 retail shops in Tokyo. Intact vegetables before being processed and ready-to-eat fresh salad products were obtained from two food factories located in the suburbs of Tokyo. Two hundred thirty-eight retail samples, 137 samples of intact vegetables, and 159 samples of fresh products were examined for aerobic plate count (APC), coliforms, Escherichia coli, Listeria spp., Staphylococcus aureus, and Bacillus cereus. The APC of retail foods were 2.1 to 5.7 log CFU/g, and the range for the coliforms was 0.1 to 2.3 log CFU/g. The APC and coliform values showed that the raw vegetables cut for salad were the most heavily contaminated among the six kinds of ready-to-eat foods examined. Although L. monocytogenes was not detected, two samples of raw vegetables and five kinds of cooked foods yielded Listeria spp. S. aureus was detected in one sample of Japanese cooked food. The APC of the intact vegetables were 2.9 to 7.3 log CFU/g upon arrival and 2.2 to 7.2 log CFU/g after 3 days storage at 10 degrees C. The APC of the fresh products were 3.4 to 7.6 log CFU/g upon arrival and 4.7 to 8.7 log CFU/g after 3 days storage at 10 degrees C. The isolation rates for coliforms were 6.1 to 50% for intact vegetables and 50 to 66.7% for fresh products. E. coli was detected only in the fresh products. B. cereus was isolated from 20.1% (17 of 81) of the intact vegetables and 9.2% (8 of 87) of the fresh products.     

Microbiological hazards involved in fresh‐cut lettuce processing

BACKGROUND: The increasing consumption of produce all over the world has resulted in increasing concern by the regulatory agencies with respect to the level of safety performed by the processors. The objective of the present study was to investigate the hazards involved in the various steps of fresh‐cut lettuce processing (reception/selection of raw material, washing, rinsing, sanitisation and final product) by means of microbiological analyses of microbial groups used as indicators of hygienic conditions and of pathogens. RESULTS: High microbial loads of mesophilic and psychrotrophic bacteria and Pseudomonas spp. were found in the ram reception (～6 log colony‐forming units (CFU) g^?1), which were reduced by a single logarithmic cycle for the last two microbial groups after the sanitisation step (P < 0.05), the latter being ineffective against the first microbial group (P > 0.05). Lower counts of yeasts and moulds, total coliforms (35 °C) and faecal coliforms (44 °C) were observed in the initial step (3.49–4.53 log CFU g^?1, 0.65–1.55 log most probable number (MPN) g^?1 and 0.50–0.90 log MPN g^?1 respectively), these values increasing significantly after the sanitisation step for yeasts and moulds (～5 log CFU g^?1) but remaining unaltered for coliforms (P > 0.05). Salmonella spp. were not found in any of the experiments carried out, while the presence of Escherichia coli was observed in the final product. CONCLUSIONS : Practices compromising the hygienic quality of the final product during commercial storage were observed and corrective measures suggested. To the best of the authors' knowledge, these are the first data on microbiological safety in Brazilian fresh‐cut processing plants. Copyright © 2008 Society of Chemical Industry     

Efficacy of chromocult coliform agar for coliform and Escherichia coil detection in foods

Chromocult coliform agar (CCA) was compared with Petrifilm Escherichia coli count plate (PEC) for identifying coliforms and E. coli in a variety of meat products. Products examined included 45 raw beef samples, 12 sausage emulsion samples, 11 samples of meat-based ready-to-eat appetizers, and 8 pork trimming samples. Coliforms from CCA and PEC were confirmed by gassing in brilliant green lactose broth plus a positive reaction on purple broth agar plus lactose after incubation at 35 degrees C for 48 h. Lauryl sulfate tryptose plus methylumbelliferyl-beta-glucuronide and tryptophan broth were used to confirm E. coli from CCA and PEC with 48-h incubations at 35 and 42.5 degrees C, respectively. API 20E test strips were inoculated for final confirmation. The overall respective confirmation percentages (CFU/g) for the PEC and the CCA methods were 93.1 and 93.7% for coliforms and 99.8 and 98.1% for E. coli, although the CCA method yielded significantly (P < 0.001) higher mean CFU/g values for both coliforms and E. coli. Regression analyses of these data indicated a strong positive linear relationship existed between the two methods over a wide CFU/g range for both coliforms and E. coli. The respective correlation coefficients obtained for coliforms and E. coli of 0.89 and 0.86 indicate that the CCA method provides a reliable optional method for these determinations in meat products.     

Chemical composition and antibacterial activity of Laurus nobilis essential oil towards foodborne pathogens and its application in fresh Tuscan sausage stored at 7 °C

The presence of foodborne pathogens in fresh Tuscan sausage has been reported and these contaminations pose a potential risk to consumers. The objective of the present study was to evaluate the antimicrobial activity of bay leaf essential oil (EO) in vitro and in fresh Tuscan sausage stored at 7 °C for 14 d. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against foodborne pathogens were determined in vitro. The lowest MIC and MBC were found for Escherichia coli (MIC = MBC = 2.5 g/L) and Yersinia enterocolitica (MIC = 1.25 g/L, MBC = 2.5 g/L). Fresh Tuscan sausages were treated with bay leaf EO at 0.05 g/100 g or 0.1 g/100 g and their shelf life was compared to a non-treated control. All groups presented low levels of rancidity (TBARS < 0.5 mg MDA/kg). The EO was able to reduce the population of total coliforms (2.8 log CFU/g) and to extend the product shelf life for two days. Although the presence of the EO affected the sensory characteristics of the sausage, it was considered acceptable by consumers at both concentrations tested. Overall, the results of this study indicate that bay leaf essential oil can be applied in fresh Tuscan sausage to improve its safety and shelf life.     

A field study of the microbiological quality of fresh produce

The Centers for Disease Control and Prevention has reported that foodborne disease outbreaks associated with fruits and vegetables increased during the past decade. This study was conducted to characterize the routes of microbial contamination in produce and to identify areas of potential contamination from production through postharvest handling. We report here the levels of bacterial indicator organisms and the prevalence of selected pathogens in produce samples collected from the southern United States. A total of 398 produce samples (leafy greens, herbs, and cantaloupe) were collected through production and the packing shed and assayed by enumerative tests for total aerobic bacteria, total coliforms, total Enterococcus, and Escherichia coli. These samples also were analyzed for Salmonella, Listeria monocytogenes, and E. coli O157:H7. Microbiological methods were based on methods recommended by the U.S. Food and Drug Administration. For all leafy greens and herbs, geometric mean indicator levels ranged from 4.5 to 6.2 log CFU/g (aerobic plate count); less than 1 to 4.3 log CFU/g (coliforms and Enterococcus); and less than 1 to 1.5 log CFU/g (E. coli). In many cases, indicator levels remained relatively constant throughout the packing shed, particularly for mustard greens. However, for cilantro and parsley, total coliform levels increased during the packing process. For cantaloupe, microbial levels significantly increased from field through packing, with ranges of 6.4 to 7.0 log CFU/g (aerobic plate count); 2.1 to 4.3 log CFU/g (coliforms); 3.5 to 5.2 log CFU/g (Enterococcus); and less than 1 to 2.5 log CFU/g (E. coli). The prevalence of pathogens for all samples was 0, 0, and 0.7% (3 of 398) for L. monocytogenes, E. coli O157:H7, and Salmonella, respectively. This study demonstrates that each step from production to consumption may affect the microbial load of produce and reinforces government recommendations for ensuring a high-quality product.     

Survey of raw milk cheeses for microbiological quality and prevalence of foodborne pathogens

Cheese may be manufactured in the United States using raw milk, provided the cheese is aged for at least 60 days at temperatures not less than 35 °F (1.7 °C). There is now increased concern among regulators regarding the safety of raw milk cheese due to the potential ability of foodborne pathogens to survive the manufacturing and aging processes. In this study, 41 raw milk cheeses were obtained from retail specialty shops, farmers’ markets, and on-line sources. The cheeses were then analyzed for the presence of Listeria monocytogenes, Salmonella, Escherichia coli O157:H7, Staphylococcus aureus, and Campylobacter. Aerobic plate counts (APC), coliform and yeast/mold counts were also performed. The results revealed that none of the enteric pathogens were detected in any of the samples tested. Five samples contained coliforms; two of those contained E. coli at less than 10² cfu/g. Three other cheese samples contained S. aureus. The APC and yeast-mold counts were within expected ranges. Based on the results obtained from these 41 raw milk cheeses, the 60-day aging rule for unpasteurized milk cheeses appears adequate for producing microbiologically safe products.     

Prevalence and counts of Salmonella spp. in minimally processed vegetables in São Paulo, Brazil

Minimally processed vegetables (MPV) may be important vehicles of Salmonella spp. and cause disease. This study aimed at detecting and enumerating Salmonella spp. in MPV marketed in the city of São Paulo, Brazil. A total of 512 samples of MPV packages collected in retail stores were tested for Salmonella spp. and total coliforms and Escherichia coli as indication of the hygienic status. Salmonella spp. was detected in four samples, two using the detection method and two using the counting method, where the results were 8.8 × 10² CFU/g and 2.4 × 10² CFU/g. The serovars were Salmonella Typhimurium (three samples) and Salmonella enterica subsp. enterica O:47:z4,z23:- (one sample). Fourteen samples (2.7%) presented counts of E. coli above the maximum limit established by the Brazilian regulation for MPV (10² CFU/g). Therefore, tightened surveillance and effective intervention strategies are necessary in order to address consumers and governments concerns on safety of MPV.