Traditional milk transformation schemes in Côte d’Ivoire and their impact on the prevalence of Streptococcus bovis complex bacteria in dairy products

Abstract

The Streptococcus bovis/Streptococcus equinus complex (SBSEC) and possibly Streptococcus infantarius subsp. infantarius (Sii) are associated with human and animal diseases. Sii predominate in spontaneously fermented milk products with unknown public health effects. Sii/SBSEC prevalence data from West Africa in correlation with milk transformation practices are limited. Northern Cô te d'Ivoire served as study area due to its importance in milk production and consumption and to link a wider Sudano-Sahelian pastoral zone of cross-border trade. We aimed to describe the cow milk value chain and determine Sii/ SBSEC prevalence with a cross-sectional study. Dairy production practices were described as non-compliant with basic hygiene standards. The system is influenced by secular sociocultural practices and environmental conditions affecting product properties. Phenotypic and molecular analyses identified SBSEC in 27/43 (62.8%) fermented and 26/67 (38.8%) unfermented milk samples. Stratified by collection stage, fermented milk at producer and vendor levels featured highest SBSEC prevalence of 71.4% and 63.6%, respectively. Sii with 62.8% and 38.8% as well as Streptococcus gallolyticus subsp. macedonicus with 7.0% and 7.5% were the predominant SBSEC species identified among fermented and unfermented milk samples, respectively. The population structure of Sii/SBSEC isolates seems to reflect evolving novel dairy-adapted, non-adapted and potentially pathogenic lineages. Northern Cô te d'Ivoire was confirmed as area with high Sii presence in dairy products. The observed production practices and the high diversity of Sii/SBSEC supports in-depth

Metaproteomic Insights Into the Microbial Community in Pozol

“…Streptococcus spp. are widely distributed bacteria in food fermentations, and they have great importance in medicine and industry (31)(32)(33)(34). Several streptococci are commensal in mammals; however, some can also cause illnesses ranging from mild to acute.…”

Safety and Quality of Milk and Milk Products in Senegal—A Review

“…Similarly, a study from Mali showed that handwashing before milking was rare, and the person milking would soak his hands in the already collected milk to lubricate the teat [ 53 ]. A study conducted in Northern Côte d’Ivoire also found a lack of handwashing and cleaning of udders before milking, as well as the storage of milk in unsuitable containers, such as those previously used for oil or chemicals and those that have not been properly cleaned [ 54 ]. Millogo et al [ 49 ] reported that milk was collected in plastic buckets or calabashes in peri-urban areas of Burkina Faso.…”

“…Millogo et al [ 49 ] reported that 21 out of 22 farmers had no cooling system in Burkina Faso, and 95.2% of participants never cooled milk after collection in Senegal [ 35 ]. In Northern Côte d’Ivoire, milk was stored for more than two hours after collection at ambient temperatures of approximately 30 °C [ 54 ].…”

“…In Burkina Faso, 13 of 22 farms used a bicycle to transport milk, and transportation times were 1 to 2 h. Nine farmers used a motorcycle or car to transport milk which decreased the transportation time to about one hour [ 49 ]. Similarly, Sanhoun et al [ 54 ] found that milk in Northern Côte d’Ivoire was transported at an ambient temperature for more than three hours.…”

“…Some farmers also do not believe in boiling milk as they believe it causes mastitis, results in udders drying up, and leads to the death of dairy cattle [ 35 ]. Often, they hesitate to sell milk to other processors who may heat treat the milk such as mini dairies [ 54 ]. The majority of participants surveyed in Senegal indicated that they never boiled raw milk before consumption (92.8%) or prior to fermentation (96.7%) at home [ 35 ].…”