Potential of Zimbabwean commercial probiotic products and strains of Lactobacillus plantarum as prophylaxis and therapy against diarrhoea caused by Escherichia coli in children

Objective: To evaluate the potential of commercial fermented products sold in the country,and strains of Lactobacillus plantarum(L,plantarum)as prophylaxis and therapy against diarrhoea in children,Methods: The antimicrobial potential of cultures of lactobacilli enriched from 4 Zimbabwean commercial food/beverage products: Dairibord Lacto sour milk(DLSM),Probrand sour milk(PSM),Kefalos Vuka cheese(KVC) and Chibuku opaque beer(COB); and four strains of L,plantarum obtained from Balkan traditional cheeses against clinical strains of Escherichia coli(E,coli) was assayed using the well diffusion method,Three commercial paediatric antidiarrhoeal drug products: Biogaia(BG),Prolife(PL) and Probio Junior(PJ) and a mutant strain of E,coli [strain 11105(ATCC)- a vitamin B-12 auxotroph and penicillin G acylase-producing strain] were used as controls,An agar diffusion assay and a competitive exclusion assay were carried out on Mueller Hinton agar,Results: Crude cultures of putative lactobacillus strains obtained from Zimbabwean dairy products(Probrand sour milk,Kefalos Vuka vuka cheese and Chibuku opaque beer) had significantly higher antimicrobial activities against clinical strains of E,coli than strains of L,plantarum isolated from Balkan cheeses(CLP1,CLP2 or CLP3) and crude microbial cultures from commercial paediatric probiotic products(BG,PJ and PL) of a culture of Lactobacillus rhamnosus LGG(P<0.05),Conclusions: The putative Lactobacilli from four commercial Zimbabwean dairy products(Probrand sour milk,Kefalos Vuka vuka cheese and Chibuku opaque beer),and three strains of L,plantarum from Balkan cheeses(CLP1,CLP2 or CLP3) exhibited high antibacterial activities that can be harnessed to control paediatric diarrhoea that is caused by pathogenic strains of E,coli,Studies to characterise the probiotic potential of the live cultures in the products and the new strains of L,plantarum are underway.

Mammalian cell cultures as models for Mycobacterium tuberculosis-human immunodeficiency virus(HIV) interaction studies:A review

Mycobacterium tuberculosis(MTB) and human immunodeficiency virus(HIV) co-infections have remained a major public health concern worldwide,particularly in Southern Africa.Yet our understanding of the molecular interactions between the pathogens has remained poor,primarily due to lack of suitable preclinical models for such studies.We reviewed the use,this far,of mammalian cell culture models in HIV-MTB interaction studies.Studies have described the use of primary human cell cultures,including monocyte-derived macrophage(MDM) fractions of peripheral blood mononuclear cell(PBMC),alveolar macrophages(AM),cell lines such as the monocyte-derived macrophage cell line(U937),T lymphocyte cell lines(CEMx174,ESAT-6-specific CD4+ T-cells) and an alveolar epithelial cell line(A549) and special models such as stem cells,three dimensional(3D) or organoid cell models [including a blood-brain barrier(BBB) cell model] in HIV-MTB interaction studies.The use of cell cultures from other mammals,including:mouse cell lines [macrophage cell lines RAW 264.7 and J774.2,fibroblast cell lines(NIH 3T3,C3 H clones),embryonic fibroblast cell lines and T-lymphoma cell lines(S1A.TB,TIMI.4 and R1.1)]; rat(T cells:Rat2,RGE,XC and HH16,and alveolar cells:NR8383) and primary guinea pigs derived AMs,in HIV-MTB studies is also described.Given the spectrum of the models available,cell cultures offer great potential for host-HIV-MTB interactions studies.