the effects of native lactobacilli isolates on clinical clostridium difficile in a laboratory scale

Shahrbanoo Asgarian,1,*

1. Tarbiat Modares University, Faculty of Medical Sciences, Department of Bacteriology



The fermented products can be a good source of potential probiotic organisms. isolation of lactobacillus from traditional products aimed with increasing quality of fermentative products, recognize starters and use in functional food products. promoting a culture of health food has been associated with decreased production of traditional dairy that destroys native strains of lactobacilli. the lack of serious study on the genetic characteristics of a microorganism as imported food starters with capacity in the transfer of unwanted features indigenous strains gives necessity. this study aimed to isolation and identification of native species lactobacillus in kohgiluyeh and boyer ahmad province was carried out the zagros east region. several probiotic species such as lactobacillus strains have direct antimicrobial effects that include inhibiting the growth of pathogenic bacteria through the production of antimicrobial factors. recently clinical studies on the use of lactobacilli and bacteriocin to deal with intestinal infection caused by prolonged treatment with antibiotics or resistant nosocomial isolates been accomplished. the spread of multiple antibiotic resistance is a significant major challenge for healthcare. lactobacilli, as the largest group of lactic acid bacteria, produce amounts of antimicrobial metabolites such as fatty acids, ammonia, hydrogen peroxide, organic acids, diacetyl, and bacteriocins. these bacteriocins are biologically active peptides against both gram-positive and negative pathogenic bacteria, protozoa, yeast, fungi, and viruses. thus, there is an urgent need to develop natural alternatives to antibiotics. lactobacilli have been shown to have a beneficial effect in the prevention of antibiotic-associated diarrhea patients with clostridium difficile infection.


Kohgiluyeh and boyer-ahmad province in the south west of iran. the province is neighboring west of khuzestan, isfahan and fars provinces of the east, from the north and south respectively of chahar mahal and bakhtiari province and bushehr. kohgiluyeh and boyer from three main areas boyer ahmad, gachsaran, kohgiluyeh is formed tribal areas as pristine areas and enable farms were selected for sampling and isolated lactobacilli from yogurt samples. isolated lactobacilli from yogurt samples on mrs agar was done in anaerobic condition. features such as the appearance of colonies, bacterial morphology, catalase and biochemical tests, growth temperatures in 37 o c and 45 o c were studied. dna extraction was performed by sina clon kit for the isolation of dna from gram-positive bacteria. designed for the qualitative detection of lactobacilli spp. was done by lactobacillus spp. pcr detection kit from iranian gene fanavar institute. the plate spot test was used for screening antibacterial effects of lactobacillus against clinical isolates of toxigenic & nontoxigenic clostridium difficile isolate.


158 yogurt samples were examined in different areas of the temperate and tropical province. lactobacilli isolates were sorted out which were divided into three groups: obligate homo-fermentative, facultative homo-fermentative, and obligate hetero-fermentative. fifty-one lactobacillus isolates from traditional yogurt showed a strong anti-clostridia activity against the clinical isolates of toxigenic & nontoxigenic clostridium difficile.


Clinical isolates have been shown that lactobacilli killed pathogens by pore formation or inhibition of cell wall synthesis. given the diversity of the lactobacilli and maintenance of native strains in areas of animal husbandry could lead to the enrichment native reserves. results are promising for the development of a multi-strain synergistic supplement for protection against clostridium difficile infection. according to the inhibitory effect of lactobacilli seems in the treatment of intestinal infections or resistant to antibiotics commonly used. different lactobacillus isolates exhibited potential anti-clostridial properties. dysbiosis results in antibiotics usage or the presence of pathogenic organisms. changes in diversity have been associated with a range of diseases including functional and infectious diseases. this problem can be prevented or reduced by lactobacilli bacteriocins. therefore, further studies need to be conducted to include in vitro and in vivo analyses, human trials or animal model studies. the proposed mechanisms of action on prevention and treatment, the ineffectiveness of probiotics are addressed with a focus on three microorganisms, saccharomyces boulardii, lactobacillus rhamnosus gg and the combination of lactobacillus casei lbc80r, lactobacillus rhamnosus clr2, and lactobacillus acidophilus cl1285. these results and recent successes are supportive for the rational design of multi-strain lactobacilli and their bacteriocins dose for clinical applications and drug formulation.


Lactobacillus, clostridium, yogurt