Niger-based researcher looks into the molecular epidemiology of S. aureus

In 1975, the government of Niger transformed the Sahelian Experimental Station of Toukounous (SEST) into a pilot dairy farm. The goal: to improve milk production of Azawak zebu, one of the best dairy cattle breeds in West Africa. Azawak zebu produce milk yields of 7–8 litres per day. Production could be better, though. Today, it is hindered by several factors, including mammary gland infections.

In Niger, data on mastitis is difficult to come by, which is why researchers have focused on identifying bacterial pathogens present in all quarters of lactating Azawak zebu cows. Once assessed, researcher Abdoulkarim Issa Ibrahim compared S. aureus isolates by their pulsotypes, virulotypes and antibiotic resistance profiles. Finally, he assessed the beneficial impact of specific hygiene and antisepsis measures during the milking process.

In 2009, 55 bacteria were isolated from the milk samples of 104 CMT-positive cows. More than half (51%) belonged to the genus Staphylococcus, to the species S. aureus (42%). Other identified bacteria belonged to the family Enterobacteriaceae (26%) and to the genera Enterococcus (13%), Bacillus (9%), and Acinetobacter (2%). Similar results were obtained in 2010, 2011 and 2012, with a total of 122 isolates of S. aureus identified.

For six months in 2011 and 2012, the percentage of CMT-positive cows was significantly reduced. This was done through improved practices, such as washing the udder pre-milking, post-milking teat dipping with chlorhexidine, and improved personal hygiene of milkers, who used a sodium hypochlorite solution to disinfect their hands. The results were positive. In 2012, for example, the proportion of CMT-positive cows decreased from 64% to 42% after just three months. After six months that number dropped to 22%.

The data Issa Ibrahim has collected can be used to help the national and local governments to conduct more surveys at SEST and in urban and peri-urban dairy cattle farms. Using this information, they plan to develop and implement effective control strategies throughout the entire dairy production chain and to organize education programs for farmers.

Abdoulkarim Issa Ibrahim is a graduate of the Inter-state School of Veterinary Medicine and Sciences of Dakar (Senegal). In 2009, he started a PhD degree at the Veterinary Faculty of the University of Liège in Belgium. He graduated in June of 2015. Currently, Issa Ibrahim is employed by the Laboratoire Central d’Elevage in Niamey.