Lactobacillus Flora Research Articles

Vulvodynia and fungal association: A preliminary report

Vulvodynia (vulvar pain syndrome) is a chronic multifactorial disease affecting almost 13million women in the USA and can lead to morbidity and a reduced quality of life.We hypothesize that an initial microbiological insult in the vagina causes modifications in the biological vaginal milieu and/or an alteration on the lactobacilli flora. The vaginal milieu responds to the insult by developing an inflammatory reaction with abnormal cytokine production.These hypotheses were tested quantifying vaginal lactobacillus and cytokines, in patients with vulvodynia compared to matched healthy controls.Our preliminary data suggest a vaginal flora alteration and an immunological response involving Candida in patients with vulvodynia. Ongoing studies will assist us to clarify these findings.

Maternal intrapartum antibiotics and decreased vertical transmission of Lactobacillus to neonates during birth

To estimate the transmission of maternal vaginal microbiota to neonates during term delivery, focusing on Lactobacillus flora in relation to various obstetric clinical factors. Fifty consecutive pregnant healthy women with singleton term pregnancies and their newborn infants. Vertical transmission of Lactobacillus flora to the newborn during delivery was evaluated in 45 mother-newborn pairs. Lactobacillus-dominant mixed flora was detected in 90% (N = 45) of vaginal samples, but only in 28% (N = 14) of neonatal cultures (transmission rate 31%). All neonates with Lactobacillus-dominant mixed flora had findings similar to those in maternal cultures. Cocci-dominant flora was the most common finding in neonates. Administration of antibiotics to the mother during the intrapartum period before birth and duration of rupture of membranes (ROM), regardless of maternal antibiotic treatment, were associated significantly with a decreased transmission rate of Lactobacillus-dominant mixed flora to neonates. Maternal intrapartum antibiotics and prolonged expectant management after ROM were associated with decreased transmission rate of vaginal Lactobacillus flora to the neonate during birth. As early colonization of Lactobacillus flora may have a preventive role in the development of allergic diseases later, the significance of intrapartum prophylactic antibiotics needs to be highlighted in forthcoming studies, especially as regards immunological development of the offspring.

Characterisation of the oral, vaginal and rectal Lactobacillus flora in healthy pregnant and postmenopausal women

Objective To investigate the hypothesis that the rectum may be an important reservoir for vaginal colonisation by Lactobacillus species. Study design We included 60 pregnant women aged 18–35 years and 80 postmenopausal women aged 55–65 years in this cross-sectional observational study. Participants had to be without clinical signs of vaginal infection and without hormone replacement therapy. Only women with normal vaginal microflora (Nugent scores 0–3) were included in the evaluation. The first oral, vaginal, and rectal smears were taken for the enumeration of lactobacilli by cultural methods and identification of dominating lactobacilli based on multiplex polymerase chain reaction (PCR). The second oral, vaginal, and rectal smears were taken for molecular lactobacilli profiling using PCR denaturing gradient gel electrophoresis (DGGE). Results 30 pregnant and 30 postmenopausal women were evaluated. On multiplex PCR, 99 colonies isolated from 30 pregnant women and 37 colonies isolated from 30 postmenopausal women were identified as being members of the genus Lactobacillus: 50% of pregnant and 33% of postmenopausal women had one or more Lactobacillus spp. recovered from their oral specimens. Around 80% of pregnant and 40% of postmenopausal women harboured one or more Lactobacillus spp. in the vagina and rectum. On PCR-DGGE, 80% of pregnant and 40% of postmenopausal women harboured the same lactobacilli isolates in both the vagina and rectum. Conclusion This study supports the hypothesis that the rectum may play an important role as a reservoir for some strains of lactobacilli that colonise the vagina.

PCR‐based identification of eight lactobacillus species and 18 hr‐HPV genotypes in fixed cervical samples of south african women at risk of HIV and BV

Vaginal lactobacilli assessed by PCR-based microarray and PCR-based genotyping of HPV in South African women at risk for HIV and BV. Vaginal lactobacilli can be defined by microarray techniques in fixed cervical samples of South African women. Cervical brush samples suspended in the coagulant fixative BoonFix of one hundred women attending a health centre for HIV testing in South Africa were available for this study. In the Ndlovu Medical Centre in Elandsdoorn, South Africa, identification of 18 hr-HPV genotypes was done using the INNO-LiPA method. An inventory of lactobacilli organisms was performed using microarray technology. On the basis of the Lactobacillus and Lactobacillus biofilm scoring, the cases were identified as Leiden bacterial vaginosis (BV) negative (BV-; n = 41), Leiden BV intermediate (BV±; n = 25), and Leiden BV positive (BV+; n = 34). Fifty-one women were HIV positive and 49 HIV negative. Out of the 51 HIV positive women, 35 were HPV infected. These 51 HIV positive women were frequently infected with HPV16 and HPV18. In addition, HPV35, HPV52, HPV33, and HPV66 were often detected in these samples. Lactobacillus salivarius and Lactobacillus iners were the most prevalent lactobacilli as established by the microarray technique. In women with HPV infection, the prevalence of Lactobacillus crispatus was significantly reduced. In both HIV and HPV infection, a similar (but not identical) shift in the composition of the lactobacillus flora was observed. We conclude that there is a shift in the composition of vaginal lactobacilli in HIV-infected women. Because of the prominence of HPV35, HPV52, HPV33, and HPV66, vaccination for exclusively HPV16 and HPV18 might be insufficient in South African HIV+ women.

The Lactobacillus flora in vagina and rectum of fertile and postmenopausal healthy Swedish women

BackgroundLactobacillus species are the most often found inhabitants of vaginal ecosystem of fertile women. In postmenopausal women with low oestrogen levels, Lactobacillus flora is diminishing or absent. However, no studies have been performed to investigate the correlation between oestrogen levels and the lactobacilli in the gut. The aim of the present study was to investigate the relation in healthy women between vaginal and rectal microbial flora as well as possible variations with hormone levels.MethodsVaginal and rectal smears were taken from 20 healthy fertile women, average 40 years (range 28-49 years), in two different phases of the menstrual cycle, and from 20 postmenopausal women, average 60 years (range 52-85 years). Serum sex hormone levels were analyzed. Bacteria from the smears isolated on Rogosa Agar were grouped by Randomly Amplified Polymorphic DNA and identified by multiplex PCR and partial 16S rRNA gene sequencing.ResultsLactobacillus crispatus was more often found in the vaginal flora of fertile women than in that of postmenopausal (p = 0.036). Fifteen of 20 fertile women had lactobacilli in their rectal smears compared to 10 postmenopausal women (p = 0.071). There was no correlation between the number of bacteria in vagina and rectum, or between the number of bacteria and hormonal levels. Neither could any association between the presence of rectal lactobacilli and hormonal levels be found.ConclusionLactobacillus crispatus was more prevalent in the vaginal flora of fertile women, whereas the Lactobacillus flora of rectum did not correlate to the vaginal flora nor to hormonal levels.

Randomized controlled trial of probiotics for the prevention of spontaneous preterm delivery associated with intrauterine infection: study protocol.

BackgroundSpontaneous preterm deliveries that occur before the 34th week of gestation, and particularly before the 32nd week of gestation, have been strongly associated to intrauterine infection, ascending from vagina, and represent the largest portion of neonatal deaths and neurological problems. Bacterial vaginosis, characterized by a diminished or absent flora of lactobacilli and increased colonization of several anaerobic or facultative microorganisms, increases two times the risk of preterm delivery before the 34th week. Trials of antibiotics failed to show efficacy and effectiveness against spontaneous preterm birth related to bacterial vaginosis. Some studies indicate benefit from selected probiotics to treat genitourinary infections, including bacterial vaginosis.ObjectiveThe purpose of this study is to evaluate the effectiveness of the early administration of selected probiotics to pregnant women with asymptomatic bacterial vaginosis/intermediate degree infection to reduce the occurrence of spontaneous preterm delivery and related neonatal mortality and morbidity.Methods/DesignWomen attending public prenatal care services in Rio de Janeiro will be screened to select asymptomatic pregnant women, less than 20 weeks' gestation, with no indication of elective preterm delivery. Those with vaginal pH > = 4.5 and a Nugent score between 4 and 10 (intermediate degree infection or bacterial vaginosis) will be randomized to either the placebo or the intervention group, after written informed consent. Intervention consists in the use of probiotics, Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14, 2 capsules a day, each capsule containing more than one million bacilli of each strain, for 6-12 weeks, up to the 24th-25th wk of gestation. Ancillary analyses include quantification of selected cervicovaginal cytokines and genotyping of selected polymorphisms. The randomization process is stratified for history of preterm delivery and blocked. Allocation concealment was designed as well as blinding of women, caregivers and outcome evaluators. The study will be supervised by an independent monitoring committee. Outcomes under study are preterm delivery (< 34- < 32 weeks of gestation) and associated neonatal complications: early neonatal sepsis, bronchopulmonary dysplasia, periventricular leukomalacia, necrotizing enterocolitis, and prematurity-related retinopathy; definitions were adapted from those recommended by the 2002 version of the Vermont-Oxford Network. Trial registration at NIH register: NCT00303082.

The Impact of Prulifloxacin on Vaginal Lactobacillus Microflora: An In Vivo Study

The aim of this study was to evaluate the In Vivo effect of a repeated-dose regimen with prulifloxacin in comparison to amoxicillin/clavulanate on vaginal lactobacillus microflora. Thirty healthy female volunteers were treated with prulifloxacin or amoxicillin/ clavulanate in this open, randomized, parallel-group, repeated-dose study. Vaginal signs and symptoms were assessed at the first doctor's Visit 0 (3 weeks prior to the start of the study), and subsequent examinations (1, 3, 5, 6, 7 and 8) (followup). Some volunteers treated with amoxicillin-clavulanate showed increased pH values and 73.3% of them had lower lactobacillus flora at Visit 3. This reduction was still present in 66.7% 3 days after the last dose and in 26.7% of subjects at the follow-up, about 7 - 13 days after the last dose. The situation was completely normalized at the second follow-up about one month after treatment stop. On the contrary, the repeated administration of prulifloxacin 600 mg tablets affected neither the pH nor the lactobacillus component of the vaginal flora in healthy fertile women. The oral administration of prulifloxacin may have advantages over some other antimicrobial agents because it preserves the normal vaginal microbiota in healthy women.

Lactobacillus nodensis sp. nov., isolated from rice bran

Gram-positive, rod-shaped, non-motile lactic acid bacteria, strains iz4b-1T, iz4b-2 and iz4c-1, were isolated in an attempt to study the composition of the Lactobacillus flora of Japanese pickles. Analysis of their 16S rRNA gene sequences revealed that the strains clustered in the Lactobacillus alimentarius group, and comparatively high similarities were shown to 'Lactobacillus tucceti' CECT 5920 (97.0 %), Lactobacillus versmoldensis KU-3T (96.4 %) and Lactobacillus nantensis LP33T (94.4 %). DNA-DNA hybridization assays clearly revealed that the isolates represented a novel taxon. The DNA G+C content was 40.6 mol% and the peptidoglycan type was L-Lys-D-Asp. Thus, these isolates represent a novel Lactobacillus species, for which the name Lactobacillus nodensis sp. nov. is proposed. The type strain is iz4b-1T (=DSM 19682T =JCM 14932T).

Changes in the predominant human Lactobacillus flora during in vitro fertilisation

BackgroundSignature matching of nucleotide sequences in the V1 and V3 regions 16S rRNA genes using pyrosequencing technology is a powerful tool for typing vaginal Lactobacilli to the species level and has been used for investigating the vaginal microbial niche.MethodsThis study has characterized the normal cultivable vaginal Lactobacillus flora at varying estradiol levels in plasma; the study comprised 17 patients undergoing ovarian stimulation for In Vitro Fertilization (IVF) treatment. The vaginal status of each participant was initially assessed as normal according to Amsel and Nugent criteria.ResultsL. crispatus, L. gasseri and/or L. jensenii were present in 10 of the patients throughout the study period, and little variation among these three species was encountered in individual patients. The flora of three women was dominated by L. delbrüeckii, L. rhamnosus or L. vaginalis. One woman exhibited a dominance of L. iners. The flora of the remaining three women were initially dominated by L. rhamnosus or L. reuteri, but as their estrogen levels rose, their flora composition altered, to become dominated by one of the three species most common in a normal, healthy vagina.ConclusionSignature matching of nucleotide sequences in the V1 and V3 regions of 16S rRNA genes is a discriminative tool for the study of vaginal Lactobacilli and can be used to track the Lactobacillus flora under a variety of physiological conditions.

Characterization of dominant cultivable lactobacilli and their antibiotic resistance profiles from faecal samples of weaning piglets

To examine the lactic acid bacteria flora of weaning piglets, to define the distribution of different lactobacilli species in piglet faecal samples, and to determine the susceptibility phenotype to 11 antibiotic of different families. The faecal samples were taken from piglets with good herd status at 11 and 28 days after weaning. The Lactobacillus isolates (n = 129) from 78 animals housed in pairs in 39 pens were preliminarily identified by their morphology and biochemical characteristics. Partial 16S ribosomal DNA (16S rDNA) was used to identify the isolates to the species level, and RAPD (randomly amplified polymorphism DNA) profiles to differentiate Lactobacillus isolates to the strain level. Based on these studies, 67 strains were selected for antibiotic resistant tests. The most numerous Lactobacillus species found in the piglets was Lactobacillus reuteri (n = 43). Other lactobacilli were L. salivarius (n = 15), L. agilis (n = 4), L. johnsonii (n = 2), L. vaginalis (n = 1), L. mucosae (n = 1) and L. gallinarum (n = 1). All the strains were susceptible to chloramphenicol, ampicillin and gentamicin. Two L. salivarius isolates and two L. reuteri isolates were found to be multiresistant. This study indicates that the faecal Lactobacillus flora in piglets consists mainly of L. reuteri, L. salivarius and L. acidophilus group lactobacilli, and the distribution of lactobacilli is similar between individuals of the same age and with the same diet. Most of the Lactobacillus isolates tested were sensitive to the antibiotics used in this study. Valuable information on Lactobacillus species distribution and their antibiotic resistance profiles in piglets is obtained.

Use of pH/whiff test or QuickVue Advanced® pH and Amines test for the diagnosis of bacterial vaginosis and prevention of postabortion pelvic inflammatory disease

Untreated bacterial vaginosis (BV) is a risk factor for postabortion pelvic inflammatory disease (PID). Eight hundred and eight women who requested therapeutic abortion were consecutively examined for the presence of BV, using either pH/whiff test or QuickVue Advanced pH and Amines test. All patients who tested positive to BV were treated with clindamycin or metronidazole prior to abortion. Based on the wet smear examination, the incidence of BV was 21.6%. Positive pH and whiff test had a sensitivity of 53%, specificity of 98% and Kappa index 0.59 (n=239). Values for QuickVue Advanced pH and Amines test were 53%, 97%, and 0.58 respectively (n=508). The incidence of PID among all patients was 2.4% after pharmacological abortion and 4.9% after surgical abortion. Among the patients with microscopic presence of BV diagnosed positive by the pH/whiff test or QuickVue Advanced pH and Amines test and treated with antibiotics, no PID occurred. Patients with negative pH/whiff test or QuickVue pH and amines test who consequently did not receive preoperative antibiotics, but who later demonstrated microscopic presence of BV, had an incidence of 14.3% (5/35) postoperative PID compared to women with normal lactobacilli flora 4.3% (10/234) (OR 3.73; 95% CI 1.21-9.21). Although the pH/whiff test and QuickVue pH and Amines test failed to ascertain BV in almost half of the participants later found to have BV, we found that preabortal screening and subsequent treatment of those who test clinically positive does lower the incidence of postabortion PID.

Effect of nursing methods and faeces consumption on the development of the bacteroides, lactobacillus and coliform flora in the caecum of the newborn rabbits

The effect of nursing method and ingestion of maternal faeces on the development of the bacteroides, lactobacillus and coliform flora of the caecum in the first 10 days of life were examined in freely nursed pups having access to maternal faeces (Group FF), pups nursed once a day and having access (Group CF), or having no access (Group CN) to maternal faeces. Colonisation of the caecum by Bacteroides commenced already on day 3 after birth. On day 2 the bacteroides counts were below 100, while on day 4 they were already between 100 and 10,000. In Group CN, the Bacteroides counts were lower (by 14 to 40%) throughout the 10-day period studied than in the groups having access to maternal faeces. Differences between groups were significant only on days 4 and 6. The average number of maternal faecal pellets left behind the doe in Group CN was 3-4 (between 0.5 and 6.4 per doe). In Groups FF and CF the pellets became smaller, crumbled and finally disappeared from the nest box, they were consumed by the pups and could be found in their gastric content. The lactobacillus counts decreased in all three groups with age, from 6.0 to 3.5 log10 CFU.g-1 (FF), 4.6 to 2.8 log10 CFU.g-1 (CF) and 5.1 to 3.1 log10 CFU.g-1 (CN), respectively. The coliform counts were higher in the first 4 days in FF (5.6 log10 CFU.g-1) than in CF (< 2 log10 CFU.g-1) and CN (2-3.6 log10 CFU.g-1) animals. Bacteroides could be cultured from the surface of the vulvar labia (max. 1000 colony count) and the vagina (max. 190 colony count), so young rabbits could become "infected" by them already in the doe's vagina. Thus prevention of ingestion of maternal faeces only slightly influenced the development of the bacteroides flora, the faeces left behind by the doe did not play an exclusive role in their colonisation.

Performance, feeding behaviour and microbial diversity in weaned piglets fed liquid diets based on water or wet wheat-distillers grain

Performance, nutrient digestibility, feeding behaviour, diarrhoea frequency and faecal microbial diversity was studied in weaned piglets allotted to dry feed (diet A), liquid feed with water (diet B) or liquid feed with wet wheat-distillers grain (diet C). There were no differences in digestibility of organic matter and energy, and the performance was similar between piglets fed liquid diets. Piglets fed diet A spent more time on eating/drinking compared with piglets fed liquid diets. The frequency of diarrhoea decreased (p < 0.05) from from diet A (11 out of 16) to diet B (6 out of 16) and further to diet C (1 out 16). The type of diet did not affect the diversity of coliform bacteria or lactobacilli, but the composition of the Lactobacillus flora was changed. The lower diarrhoea frequency when feeding diet C may be due to a prophylactic effect induced by the inclusion of wet wheat-distillers grain in the diet.

Lactobacillus gastricus sp. nov., Lactobacillus antri sp. nov., Lactobacillus kalixensis sp. nov. and Lactobacillus ultunensis sp. nov., isolated from human stomach mucosa

In an attempt to study the composition of the Lactobacillus flora from mucosa of human stomach, 16S rRNA gene sequences of 129 isolates were analysed. For 15 of these, the results differed significantly from known sequences, and additional tests were performed to determine whether these isolates represented as yet unrecognized species. Phenotypic and genetic characteristics revealed that these isolates represented four novel Lactobacillus species. Two belong to the Lactobacillus reuteri and the other two to the Lactobacillus delbrueckii subgroup of Lactobacillus. The names Lactobacillus gastricus sp. nov., Lactobacillus antri sp. nov., Lactobacillus kalixensis sp. nov. and Lactobacillus ultunensis sp. nov. are proposed, with the respective type strains Kx156A7T (=LMG 22113T=DSM 16045T=CCUG 48454T), Kx146A4T (=LMG 22111T=DSM 16041T=CCUG 48456T), Kx127A2T (=LMG 22115T=DSM 16043T=CCUG 48459T) and Kx146C1T (=LMG 22117T=DSM 16047T=CCUG 48460T).

Effects of Two Probiotic Lactobacillus Strains on Jejunal and Cecal Microbiota of Broiler Chicken under Acute Heat Stress Condition as Revealed by Molecular Analysis of 16S rRNA Genes

We examined the effects of probiotic Lactobacillus strains of Lactobacillus agilis JCM 1048 and Lactobacillus salivarius subsp. salicinius JCM 1230 on jejunal and cecal microbiota of broiler chicken under heat stress condition using terminal restriction fragment length polymorphism (T-RFLP) analysis. The jejunal bacterial community was limited to a few bacterial groups, mostly Lactobacillus spp. A relatively abundant and higher prevalence of Lactobacillus spp. were observed in the jejunal and cecal microbiota of the probiotic chickens compared with those of the control chickens under heat stress condition. In general, the probiotic strains did not significantly affect the abundance of L. agilis and L. salivarius in chicken intestine but clearly contributed to increasing their prevalence in the probiotic chickens. The probiotic Lactobacillus strains enriched the diversity of Lactobacillus flora in chicken jejunum and cecum by increasing the abundance and prevalence of Lactobacillus spp. inhabiting the intestine. The richness of Lactobacillus species tended to be similar among the jejunal and cecal microbiota. The bacterial community of cecum was complex and age-dependent. The major components of the cecal microbiota were clostridia and lactobacilli. The Clostridium subcluster XIVa was the most predominant group in chicken cecum. Probiotic Lactobacillus strains restored the microbial balance and maintained the natural stability of indigenous bacterial microbiota following heat stress-induced changes.

Lactobacillus saerimneri sp. nov., isolated from pig faeces.

In studying the composition of the Lactobacillus flora of faeces from pigs fed different diets, isolates with notable differences in their 16S rRNA gene sequence compared to recognized species were found. Phenotypic characteristics together with 16S rRNA gene sequences revealed that the isolates represented a novel species belonging to the Lactobacillus mali subgroup of lactobacilli. The name Lactobacillus saerimneri sp. nov. is proposed (type strain GDA154T=LMG 22087T=DSM 16049T=CCUG 48462T).

Les lactobacilles : propriétés, habitats, rôle physiologique et intérêt en santé humaine

Regarding their morphology, their metabolism and their phylogeny, lactobacilli appear as a heterogeneous group of bacteria. Related to this diversity, the identification of lactobacilli at the species level is often problematic and in some cases, an accurate identification is only obtained using molecular or polyphasic approaches. Species identification remains essential for describing the bacterial population colonizing various niches and studying their dynamics. Lactobacilli are ubiquitous bacteria occurring in low numbers at all plant surfaces but they grow luxuriously in decaying plant material and fruits. These bacteria are used as a low-cost mean to preserve and transform plant and animal raw matters such as cereals, tubers, grass, vegetables, milk and dairy products, meat and fish. Thus, lactobacilli have a crucial role in human nutrition. Lactobacilli are commensals of human and animals. Lactobacillus jensenii, L. crispatus and L. gasseri are the predominant species in the normal vaginal microbial flora in women of reproductive age and their presence is correlated with a control of vaginal infections. L. ruminis, L. gasseri, L. reuteri and L. salivarius are the most frequent species detected in adult human faecal samples ( L. acidophilus is the species frequently found in human newborns faecal fluids) while L. plantarum, L. gasseri, L. rhamnosus and L. paracasei are detected in healthy human oral and rectal mucosa. The role of the autochthonous Lactobacillus flora of the human digestive tract is not yet completely elucidated. Lactobacilli may contribute to the intestinal microflora balance. In the mouth, they contribute to the development of dental plaques in association with Streptococcus mutans. Many applications of lactobacilli as probiotics are suggested but only few have shown clearly demonstrated effects on human health (e.g. treatment of lactase-deficiency, prevention and treatment of rotavirus induced diarrhoea in children). Recent data obtained with probiotics in the treatment of allergic diseases or inflammatory bowel diseases are particularly promising.

Bacterial vaginosis and miscarriage.

This review aims to summarize current knowledge about the relationship between bacterial vaginosis and miscarriage. Studies investigating the relationship between bacterial vaginosis and infertility, implantation and early pregnancy loss have produced conflicting results. One study demonstrated a beneficial effect of colonization with hydrogen peroxide producing lactobacilli. A community based study found no association between bacterial vaginosis and first trimester loss, but a positive association with early second trimester loss. In a randomized controlled trial, treatment of bacterial vaginosis with oral clindamycin was associated with a fivefold reduction in the incidence of late miscarriage. The relationship between bacterial vaginosis and infertility and first trimester loss needs further elucidation. Measures to support a healthy lactobacillus flora such as probiotic therapy warrant study. The randomized controlled trials of clindamycin treatment need to be replicated in different settings.

Lactobacillus strains isolated from Danbo cheese as adjunct cultures in a cheese model system

Isolates of Non-Starter Lactic Acid Bacteria (NSLAB) from six ripened Danbo cheeses of different ages and of different brands were examined. Special emphasis was on the genus Lactobacillus with the aim of investigating their role in cheese maturation. Thirty-three isolates were typed by the PCR-based method, Randomly Amplified Polymorphic DNA (RAPD). Ten RAPD types were found and 70% of the isolates were of RAPD types found in more than one cheese. The different RAPD types were identified to species level by Temporal Temperature Gradient Gel Electrophoresis (TTGE). Most of the isolates were identified as Lactobacillus paracasei (76%), but also Lactobacillus curvatus, Lactobacillus plantarum, Lactobacillus rhamnosus and some taxa originating from the starter culture were detected. In one cheese, no lactobacilli were found . One strain of the most frequent Lactobacillus RAPD type from each of the five cheeses with a Lactobacillus flora was used as adjunct cultures in a cheese model system. Four of the five adjuncts were re-isolated during ripening. Two adjunct containing model cheeses received higher flavour scores than the control while two other were associated with off-flavours. The two model cheeses with off-flavour had a similar microflora and both were after 13 weeks of ripening dominated by a strain identified as L. plantarum.

Distribution of theLactobacillus acidophilusComplex in Human Fecal Specimens Examined by Restriction Fragment Length Polymorphism of the 16S rRNA Genes

Fresh fecal samples from healthy volunteers were examined for their content of the Lactobacillus acidophilus complex (LAC). A two-step isolation method for fecal lactobacilli was developed and employed in this study. Isolates of lactobacilli were identified according to their restriction fragment length polymorphism (RFLP) of genes coding for ribosomal RNA. Our results suggested that all samples contain lactobacilli and the most dominant species of human fecal lactobacilli is L. paracasei. In addition, several strains of LAC were recovered from specimens of volunteers. Among six LAC species, namely, A1: L. acidophilus, A2: L. crispatus, A3: L. amylovorus, A4: L. gallinarum, B1: L. gasseri, and B2: L. johnsonii, isolates classified into cluster B were recovered from 6 out of 15 volunteers; however isolates of cluster A were recovered from 3 of 15 volunteers. Four of 15 volunteers had strains of L. gasseri, 3 of them had strains of L. johnsonii, and strains of L. amylovorus were also isolated from specimens of 3 of 15 volunteers. These findings suggest that group B of LAC is the predominant cluster of LAC found in human feces and L. amylovorus was the only species of cluster A found in this study. No volunteer with blood type O had LAC in the fecal Lactobacillus flora.