Source Of Lactobacilli Research Articles

Identification and Antibacterial Activity of Lactobacillus Isolated from Different Raw Honey in Mostaganem Province, Algeria

Background: The increase of multidrug-resistant pathogens causes increased concerns about the efficacy of conventional treatment, which requires the search for new alternatives to antibiotics. The present study aimed to evaluate the antibacterial activity of lactobacilli isolated from eight (n=8) typical Apis mellifera honey produced in Mostaganem region against four pathogenic bacteria responsible of bovine mastitis. Methods: Lacbacilli strains, isolated from different media were firstly presumptively identified by catalase test, Gram staining and cells morphology, than confirmed by partial 16S rRNA sequence analysis. Antibacterial activity of isolates was determined by the overlay agar method. Antibiotic susceptibility of mastitis pathogens was tested by disk diffusion technique. Result: Two species of lactobacilli were isolated and identified as Lactobacillus plantarum and Lactobacillus pentosus. Antibiotic sensitivity test demonstrated that mastitis pathogens showed the resistance to antibiotics tested. All the isolates showed antimicrobial activity with inhibition zone diameters ranged from 5±0.02 to 21±2.12 mm. The results revealed that honey can be considered as a source of Lactobacillus with antibacterial activities which can be used as alternative treatment of bovine mastitis.

Oral supplementation with lactobacilli to prevent colorectal cancer in preclinical models.

Colorectal cancer (CRC) is still a major threat for public health, as it is the third most common cancer in men and the second in women and it ranks second among tumors in terms of mortality. Evidence from the last decades emphasizes the complex role of gut microbial composition in CRC development. Historically, it is believed that dairy products, a source of lactobacilli and other lactic acid bacteria, are beneficial for human health and help in preventing CRC. We searched online literature for trials evaluating the preventive role of lactobacilli in CRC animal models. Most of selected studied assessed a relevant role of lactobacilli in preventing CRC and precursor lesions. Mechanisms through which this effect was achieved are supposed to regard immunomodulation, regulation of apoptosis, gut microbial modulation, genes expression, reduction of oxidative stress and others. Lactobacilli oral supplementation is reported to be effective in preventing CRC in animal models, even if the underlying mechanisms of action are still not fully understood.

1342 A Rare Presentation of Lactobacillus Paracasei Endocarditis With Involvement of Aortic Prosthetic Valve in a Patient With Septic Shock Due to Acute Cholecystitis

INTRODUCTION: Endocarditis caused by Lactobacilli species is rare and usually manifests in patients with severe comorbidities, congenital heart disease, or prosthetic valves. Lactobacilli species are gram-positive coccobacilli mostly found in the gastrointestinal tract flora. Current literature shows an association of this bacterium with the use of probiotics. We hypothesize a possible association between acute cholecystitis and the occurrence of Lactobacillus endocarditis in a patient with no history of use of probiotics. CASE DESCRIPTION/METHODS: A 75-year-old female with a history of Birt-Hogg-Dube Syndrome with multiple spontaneous pneumothoraxes, COPD, aortic stenosis status post prosthetic aortic valve (AV) replacement, presented with acute respiratory failure and septic shock. She was diagnosed with acute cholecystitis, severe aortic regurgitation, and found to have lactobacillus bacteremia. We started her on empiric antibiotic coverage and later switched to penicillin G and gentamicin following three positive blood cultures for Lactobacillus paracasei. A transesophageal echocardiogram showed vegetation with emerging severe aortic regurgitation, degeneration, and perforation of AV leaflet when compared with echocardiogram one year ago. A CT-thorax demonstrated pan lobular emphysema with large cysts and pneumatoceles at the lung bases. Bacteremia persisted for two weeks after initiation of antibiotic therapy. Treatment with penicillin G and gentamicin was deemed necessary for up to 4 weeks after definitive surgical treatment. However, the patient's severe lung condition complicated preoperative clearance, and she was transferred to a specialized center for open-heart AV replacement. DISCUSSION: Very few cases of Lactobacillus endocarditis are reported in the literature. A handful of studies describe some implicated pathogenesis of the Lactobacillus in the blood as induced by cholecystitis. Other studies suggest that the increased presence of Lactobacillus in the respiratory tract in cases of severe lung pathology can lead to hematogenous dissemination to the heart valves. However, the association between Lactobacillus species and prosthetic valve material (and implication with endocarditis) is currently well-established. All things considered, and despite the lack of histopathology, we suggest that the source of Lactobacillus was likely the acute cholecystitis, and the presence of lung comorbidities and prosthetic AV further exacerbated the patient's condition.

Evaluation of antimicrobial properties and their substances against pathogenic bacteria in-vitro by probiotic Lactobacilli strains isolated from commercial yoghurt

Milk and milk products have been used by human population since ancient ages and have been a well known source of Lactobacilli. The beneficial effects of viable probiotic bacteria as dietary supplements have gained huge research interest, Lactobacillus spp. with probiotic characteristics are widely used to prepare fermented dairy products such as yoghurts, milk-shakes etc. The goal of the present study was to examine Lactobacillus species with potential activities, total four different companies of Yoghurt samples were collected from City market of Gulbarga region for isolation of probiotic Lactobacillus species. Among the samples, 32 lactic acid bacteria strains were isolated, thirteen (13/32) best Lactobacillus isolates were selected by preliminary screening as potential probiotics with antimicrobial activity against pathogenic bacteria. All the Lactobacillus isolates were then characterized in vitro for their probiotic characteristics and antimicrobial activities against pathogens. The isolates were resistant to NaCl (1–6%), bile salt (0.5–3%) and showed good growth in the acidic condition, while maximum growth was observed at pH around 6.0. All the isolates were susceptible to clinical antibiotics; also the isolates were exhibited effective aggregation and hydrophobicity studies. Based on the results, selected Lactobacillus isolates were considered as novel and potential probiotic bacteria. Thus, further extensive research on isolation and characterization of probiotic bacteria from local dairy products and their growth optimization might be necessity for development of probiotic enriched food supplement and human health benefits through prevention and controlling of bacterial infections.

Screening and Characterization of Lactobacillus sp. from the Water of Cassava’s Fermentation for Selection as Probiotics

ABSTRACTThe present study aimed to evaluate selected probiotic properties of Lactobacilli isolated from the water of submerged cassava fermentation. Following Lactobacilli isolation, isolates were screened for their antimicrobial activity. Acid and bile tolerances, bile salt hydrolase (Bsh) activity spectrum were assessed. Among the 113 isolates obtained, 16 showed a broad antimicrobial activity spectrum against the indicator microorganisms. From these 16, 12 were found acid and bile resistant. They hydrolyzed glycoconjugated or tauroconjugated bile salts. From the four bile Bsh genes screened, only Bsh-Lp1 was found in five isolates. They identified as Lactobacillus paraplantarum, Lactobacillus paracasei, Lactobacillus brevis, and Lactobacillus plantarum. Based on the principal component analysis, L. paracasei 62L, L. plantarum 85L and 86L were selected as the most promising strains. These results suggest that water from submerged cassava fermentation can be a source of Lactobacilli with high probiotic potential.

Genome sequencing and analysis of the first complete genome of Lactobacillus kunkeei strain MP2, an Apis mellifera gut isolate.

Background. The honey bee (Apis mellifera) is the most important pollinator in agriculture worldwide. However, the number of honey bees has fallen significantly since 2006, becoming a huge ecological problem nowadays. The principal cause is CCD, or Colony Collapse Disorder, characterized by the seemingly spontaneous abandonment of hives by their workers. One of the characteristics of CCD in honey bees is the alteration of the bacterial communities in their gastrointestinal tract, mainly due to the decrease of Firmicutes populations, such as the Lactobacilli. At this time, the causes of these alterations remain unknown. We recently isolated a strain of Lactobacillus kunkeei (L. kunkeei strain MP2) from the gut of Chilean honey bees. L. kunkeei, is one of the most commonly isolated bacterium from the honey bee gut and is highly versatile in different ecological niches. In this study, we aimed to elucidate in detail, the L. kunkeei genetic background and perform a comparative genome analysis with other Lactobacillus species.Methods. L. kunkeei MP2 was originally isolated from the guts of Chilean A. mellifera individuals. Genome sequencing was done using Pacific Biosciences single-molecule real-time sequencing technology. De novo assembly was performed using Celera assembler. The genome was annotated using Prokka, and functional information was added using the EggNOG 3.1 database. In addition, genomic islands were predicted using IslandViewer, and pro-phage sequences using PHAST. Comparisons between L. kunkeei MP2 with other L. kunkeei, and Lactobacillus strains were done using Roary.Results. The complete genome of L. kunkeei MP2 comprises one circular chromosome of 1,614,522 nt. with a GC content of 36,9%. Pangenome analysis with 16 L. kunkeei strains, identified 113 unique genes, most of them related to phage insertions. A large and unique region of L. kunkeei MP2 genome contains several genes that encode for phage structural protein and replication components. Comparative analysis of MP2 with other Lactobacillus species, identified several unique genes of L. kunkeei MP2 related with metabolism, biofilm generation, survival under stress conditions, and mobile genetic elements (MGEs).Discussion. The presence of multiple mobile genetic elements, including phage sequences, suggest a high degree of genetic variability in L. kunkeei. Its versatility and ability to survive in different ecological niches (bee guts, flowers, fruits among others) could be given by its genetic capacity to change and adapt to different environments. L. kunkeei could be a new source of Lactobacillus with beneficial properties. Indeed, L. kunkeei MP2 could play an important role in honey bee nutrition through the synthesis of components as isoprenoids.

Isolation of Lactobacilli and Bifidobacteria Species from Human Breast Milk

Background: Bacterial colonization of the infant gut is a gradual process that exerts a strong influence on the health status of the host. The source of bacterial diversity in breast fed babies remains unclear. For many decades, breast milk has been regarded as a sterile body fluid which exerts its influence on the infant's microbiota environment via presenting only some growth factors and optimal conditions for helping the growth of bacteria. However, in recent years, breast milk has been hypothesized to be a source of commensal bacteria for the infant gut. Objective: This study aimed at searching for bacteria in breast milk to assess the role of breast milk as their probable source. Methodology: Samples of breast milk were obtained from 50 lactating women and were tested for the presence of different bacteria, using specific media and specific biochemical reactions. Results: Culture of the 50 breast milk specimens showed growth of different species of lactobacilli in 100% of the specimens and bifidobacteria in the milk of 14 mothers (28%). Conclusion: breast milk can be a source of lactobacilli and bifidobacteria for the infants

Lemon Juice Synergistically Preserved with Lactobacilli Ameliorates Inflammation in Shigellosis Mice

The use of probiotic Lactobacilli has moved from concept to implement in different applications. The study was carried out to establish the synergistic role of co-cultures of Lactobacillus casei, L. delbrueckii, L. plantarum and L. helveticus in lemon juice (LJ) preservation as well as investigate the inflammatory- and toxicity profiles of biopreserved LJ ingested shigellosis mice. Lactobacilli were cultured individually and cocultured with different combinations. Four strain Lactobacilli had significant preservative activity than any other combinations in both free and microencapsulated Lactobacilli. The four microencapsulated bacteria extended shelf-life of the LJ in about two weeks at 4°C. The free or microencapsulated bacteria were increased acidic pH into LJ. It was evidently proved that microencapsulated cocultures of different strains remained viable over a long period of time and the probiotically fermented juice were potentially inhibiting the pathogenic growth. For inflammatory acute shigellosis, therapies were divided into six groups: LJ only; LJ containing pathogenic bacteria (PB); LJ containing curd, the source of Lactobacilli; LJ containing curd and PB; LJ containing four Lactobacilli LAB1,3,4,6 and LJ containing chemical preservatives (PR, prophyl paraben and methyl paraben 9:1). Lactobacilli preserved LJ were found to be favorably lower inflammatory haematological profiles such as ESR, WBC count and C-reactive protein (CRP) agglutination in acute shigellosis mice. In addition, biopreserved LJ was safe owing to normal ranges of SGPT, SGOT, SALP and AA levels in shigellosis mice. Prospective studies on mechanisms of the probiotic activities might be enable their new medical applications for food preservation and treatment of inflammatory dysentery patients.

733. Lactobacilli in Cheddar cheese: III. The source of lactobacilli in cheese

Lactobacilli occur in large numbers in cheese (1,2,3,4) and may be responsible for or influence the formation of flavour. It is therefore desirable to find the source of the lactobacilli and the route by which they enter the cheese, so that the cheese flora may be controlled