Occurrence of pathogenic bacteria in raw milk, cultured pasteurised milk and naturally soured milk produced at small-scale dairies in Zimbabwe

Gran, H.M.; Wetlesen, A.; Mutukumira, Anthony N.; Rukure, Grace; Narvhus, Judith

doi:10.1016/s0956-7135(02)00117-2

Cited by 59 publications

(54 citation statements)

References 15 publications

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“…However, they concurred with previous studies in Zimbabwe that showed high TBC in raw milk (Gran et al, 2003). While it is reported that raw milk TBC should be less than 100 000 cfu/ml (Gosta, 1995), Zimbabwean food regulations require that raw milk should not exceed 20 000 cfu/ml (Food and Food Standard Act, 2001).…”

Section: Discussionsupporting

confidence: 88%

“…While it is reported that raw milk TBC should be less than 100 000 cfu/ml (Gosta, 1995), Zimbabwean food regulations require that raw milk should not exceed 20 000 cfu/ml (Food and Food Standard Act, 2001). High bacterial load in raw milk has been attributed to poor hygienic practices that include failure to properly clean the udder and use of contaminated water among others (Gran et al, 2003). The bacteria in milk handler are also likely to find its way into the raw milk and other subsequent stages of milk processing (Gran et al, 2003).…”

Section: Discussionmentioning

confidence: 99%

“…The latter product taking greater preference, because it is used as a relish which provides proteins at a low cost for the lower class while it is a delicacy for the affluent that they consume as part of the main meal or dessert. Due to the faltering economy of Zimbabwe, many dairy farmers have been downsizing operations and ultimately preferring to sell their milk product directly to consumers without supplying any processor (Gadaga et al, 1999;Gran et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

“…Staphylococcus aureus among other pathogens is destroyed by pH lower than 5 (Medveďová and Valík, 2012). However, emerging research has shown that some strains of E. coli can survive the low pH (Gran et al, 2003;Bore et al, 2007). A combination of harsh conditions and prolonged exposure time has been said to result in microbes building some adaptation mechanism (Lucking et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

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Microbial species of safety concern in milk from informal processors in Harare, Zimbabwe

Chimuti¹,

Midzi²,

Njage³

et al. 2016

Afr. J. Microbiol. Res.

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In this study, the bacteriological quality and the presence of Staphylococcus aureus, Escherichia coli O157:H7, Bacillus cereus, Salmonella species, and Pseudomonas species were studied in raw milk, cultured milk, milk handlers and packaging containers. A total of 36 samples were collected over 3 months from three different farmers. Samples were analyzed for means of counts per milliliter of milk for total bacterial count (TBC), total coliform count (TCC), total E. coli count (TEC), S. aureus, B. cereus, Salmonella spp. and Pseudomonas spp. Microbial load ranged between 0.81 and 7.6 log 10 cfu/ml for various critical sampling locations. Isolates of E. coli, S. aureus and B. cereus were taken for simple polymerase chain reaction (PCR) to investigate the presence of virulent genes, rfB, sei, and cytK with amplicon sizes of 1.0 kb, 500 bp and 320 bp, respectively. The sei gene was detected in 19% of the samples and 2.8% were found to have the cytK gene. The rfB gene could not be picked in E. coli. The results show poor hygienic practices at the processors and potential risk to the consumers.

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Section: Discussionsupporting

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Microbial species of safety concern in milk from informal processors in Harare, Zimbabwe

Chimuti¹,

Midzi²,

Njage³

et al. 2016

Afr. J. Microbiol. Res.

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show abstract

“…Therefore, in most countries, restrictions and legislation regulating the marketing of unpasteurized milk have been introduced to minimize health risks associated with milk products (European Commission, 2000). However, these do not ensure the safety and quality of dairy products, because diseases associated with milk could occur because of insufficient pasteurization and/or cross-contamination (Altekruse et al, 1998; da Silva et al, 1998; Gran et al, 2003). Moreover, even though the heating process is sufficient to kill vegetative microorganisms, this treatment may be inadequate to remove microbial spores and toxins, such as Bacillus cereus and Staphylococcus aureus (Rall et al, 2008;Zwietering et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

Development of Kinetic Models Describing Kinetic Behavior of Bacillus cereus and Staphylococcus aureus in Milk

Kim¹,

Lee²,

Yoon³

et al. 2013

Korean Journal for Food Science of Animal Resources

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This study developed predictive models to evaluate the kinetic behaviors of Bacillus cereus and Staphylococcus aureus in milk during storage at various temperatures. B. cereus and S. aureus (3 Log CFU/mL) were inoculated into milk and stored at 10 o C, respectively, while bacterial populations were enumerated. The growth data were fitted to the modified Gompertz model to estimate kinetic parameters, including the maximum specific growth rate (µ max ; Log CFU/[mL·h]), lag phase duration (LPD; h), lower asymptote (N 0 ; Log CFU/mL), and upper asymptote (N max ; Log CFU/mL). To describe the kinetic behavior of B. cereus and S. aureus, the parameters were fitted to the square root model as a function of storage temperature. Finally, the developed models were validated with the observed data, and Bias (B) and Accuracy (A) factors were calculated. Cell counts of both bacteria increased with storage time. Primary modeling yielded the following parameters; µ max : 0.14-0.75 and 0.06-0.51 Log CFU/mL/h; LPD: 1.78-14.03 and 0.00-1.44 h, N 0 : 3.10-3.37 and 2.09-3.07 Log CFU/mL, and N max : 7.59-8.87 and 8.60-9.32 Log CFU/mL for B. cereus and S. aureus, respectively. Secondary modeling yielded a determination of coefficient (R 2 ) of 0.926-0.996. B factors were 1.20 and 0.94, and A factors were 1.16 and 1.08 for B. cereus and S. aureus, respectively. Thus, the mathematical models developed here should be useful in describing the kinetic behaviors of B. cereus and S. aureus in milk during storage.

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Food safety management systems performance in African food processing companies: a review of deficiencies and possible improvement strategies

Kussaga

Jacxsens

Tiisekwa

et al. 2014

J. Sci. Food Agric.

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This study seeks to provide insight into current deficiencies in food safety management systems (FSMS) in African food-processing companies and to identify possible strategies for improvement so as to contribute to African countries' efforts to provide safe food to both local and international markets. This study found that most African food products had high microbiological and chemical contamination levels exceeding the set (legal) limits. Relative to industrialized countries, the study identified various deficiencies at government, sector/branch, retail and company levels which affect performance of FSMS in Africa. For instance, very few companies (except exporting and large companies) have implemented HACCP and ISO 22000:2005. Various measures were proposed to be taken at government (e.g. construction of risk-based legislative frameworks, strengthening of food safety authorities, recommend use of ISO 22000:2005, and consumers' food safety training), branch/sector (e.g. sector-specific guidelines and third-party certification), retail (develop stringent certification standards and impose product specifications) and company levels (improving hygiene, strict raw material control, production process efficacy, and enhancing monitoring systems, assurance activities and supportive administrative structures). By working on those four levels, FSMS of African food-processing companies could be better designed and tailored towards their production processes and specific needs to ensure food safety.

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Occurrence of pathogenic bacteria in raw milk, cultured pasteurised milk and naturally soured milk produced at small-scale dairies in Zimbabwe

Cited by 59 publications

References 15 publications

Microbial species of safety concern in milk from informal processors in Harare, Zimbabwe

Microbial species of safety concern in milk from informal processors in Harare, Zimbabwe

Development of Kinetic Models Describing Kinetic Behavior of Bacillus cereus and Staphylococcus aureus in Milk

Food safety management systems performance in African food processing companies: a review of deficiencies and possible improvement strategies

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