Fecal Origin Research Articles

Sewage reflects the microbiomes of human populations.

ABSTRACTMolecular characterizations of the gut microbiome from individual human stool samples have identified community patterns that correlate with age, disease, diet, and other human characteristics, but resources for marker gene studies that consider microbiome trends among human populations scale with the number of individuals sampled from each population. As an alternative strategy for sampling populations, we examined whether sewage accurately reflects the microbial community of a mixture of stool samples. We used oligotyping of high-throughput 16S rRNA gene sequence data to compare the bacterial distribution in a stool data set to a sewage influent data set from 71 U.S. cities. On average, only 15% of sewage sample sequence reads were attributed to human fecal origin, but sewage recaptured most (97%) human fecal oligotypes. The most common oligotypes in stool matched the most common and abundant in sewage. After informatically separating sequences of human fecal origin, sewage samples exhibited ~3× greater diversity than stool samples. Comparisons among municipal sewage communities revealed the ubiquitous and abundant occurrence of 27 human fecal oligotypes, representing an apparent core set of organisms in U.S. populations. The fecal community variability among U.S. populations was significantly lower than among individuals. It clustered into three primary community structures distinguished by oligotypes from either: Bacteroidaceae, Prevotellaceae, or Lachnospiraceae/Ruminococcaceae. These distribution patterns reflected human population variation and predicted whether samples represented lean or obese populations with 81 to 89% accuracy. Our findings demonstrate that sewage represents the fecal microbial community of human populations and captures population-level traits of the human microbiome.

Hygiene and health risks associated with the consumption of edible lamellibranch molluscs

Edible lamellibranch molluscs are frequently the cause of very serious outbreaks of food poisoning. Microbiological suitability for human consumption, according to EC Reg. n. 1441/2007, is only based on two faecal bacteriological contamination parameters (Escherichia coli and Salmonella) and does not consider other microorganisms which are naturally present within the marine environment and are potentially pathogenic such as those belonging to the genus Vibrio. In this study, a total of 540 samples of edible lamellibranch molluscs (mussels, clams and oysters) bred in Sardinia were analyzed for E. coli and Salmonella, according to EC Reg n. 1441/2005, and for the presence of Vibrios of major public health interest. Environmental parameters (seawater temperature and salinity) were also recorded. The 40% (n=216) of samples were positive for Vibrio while the levels of E. coli were above the legal European limit only in 6.4% of samples. A correlation between the presence of micro-organisms of faecal origin and potentially harmful Vibrios to human health was not observed. Vibrio alginolyticus was the most common in 68% of isolated species, followed by Vibrio parahaemolyticus in 22.6%, Vibrio cholerae in 6% and Vibrio vulnificus in 1.1%. Virulence gene (trh sequence) was present in 1.6% of the V. parahaemolyticus-positive samples. The V. cholerae, V. vulnificus and V. alginolyticus strains detected were non toxigenic. The absence of genes encoding major virulence factors in the studied strains does not exclude the possibility of exposure to pathogenic strains. This study indicates the potential health risk associated with the presence of pathogenic Vibrios in edible lamellibranch molluscs bred in Sardinia, where shellfish production is very important to the local economy.

Microorganisms as contaminants and natural tracers: a 10-year research in some carbonate aquifers (southern Italy)

Limestone aquifers provide the main drinking water resources of southern Italy. Due to cattle grazing and/or manure spreading, these aquifers are often characterized by microbial contamination of groundwater. The aim of this paper is to summarize the results obtained during a 10-year research carried out in experimental field sites in southern Italy, analyzing (1) the influence of the topsoil of pyroclastic origin on the migration of microbial cells from the ground towards the groundwater, and then on the groundwater vulnerability, (2) the influence of the rainfall regime on the breakthrough at the springs, (3) the reliability of thermotolerant coliforms and fecal enterococci as bacterial indicators of microbial contamination, and (4) the effectiveness of microorganisms as natural tracers for some hydrogeological purposes. The results obtained showed that fecal enterococci are a more reliable indicator than thermotolerant coliforms for detecting contamination and that the entity and distribution over time of microbial contamination of fecal origin are influenced by several factors, such as precipitation regime, thermal regime and existence and thickness of the topsoil of pyroclastic origin. Moreover, the migration of a significant amount of bacterial cells through the topsoil and the underlying carbonate rocks allows the utilization of microorganisms as effective natural tracers, to be coupled with other classic tracers to study the recharge and the flow processes. In a broader perspective, these results can be used to optimize the investigations in other hydrogeological scenarios, with emphasis on those where different water types coexist and interact in same aquifer systems.

Assessment of source tracking methods for application in spring water.

For discriminating between human and animal faecal contamination in water, microbial source tracking (MST) approaches using different indicators have been employed. In the current study, a range of 10 such MST indicators described in the scientific literature were comparatively assessed. Bacteriophages infecting host strains of Bacteroides (GA-17, GB-124 and ARABA 84) as well as sorbitol-fermenting bifidobacteria proved useful for indicating human faecal contamination while Rhodococcus coprophilus was associated with animal-derived faecal contamination. These potential source indicators were present in samples of faecal origin, i.e. either in human wastewater or animal waste, from many different regions in Switzerland and therefore showed a geographic stability. In addition, the MST indicators were abundant in surface water and were even sensitive enough to detect faecal contamination in spring water from two study areas in Switzerland. This is the first study that has compared and successfully applied MST methods in spring water.

Evaluation of bile tolerance in dairy and human origin Lactobacillus fermentum strains

Normal 0 false false false EN-IN X-NONE X-NONE Eleven Lactobacillus fermentum strains including seven dairy and four faecal origin were studied for in vitro bile tolerance at 0, 0.3, 0.6, 0.9, 1.2, 1.5 and 1.8 % bile concentration to assess their probiotic potential. At 0.3 and 0.6% bile concentration except NCDC-400, all dairy origin strains shown 3 to 5 log reduction in count, while faecal origin strains did not show much reduction. Almost similar trend was observed for dairy strains at 1.2 to 1.5 % bile concentration whereas BIF-18, BIF, 19 and BIF 20 from faecal strains shown better growth. Lactobacillus fermentum BIF-19 from faecal and Lactobacillus fermentum NCDC-400 from dairy origin were most bile tolerant. Out of all strains BIF-19 exhibited highest survival in all concentration of bile. /* Style Definitions */ table.MsoNormalTable {mso-style-name:Table Normal; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri,sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Times New Roman; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;}

Water microbial quality during drinking water treatment technology and distribution provided by two Romanian companies

Under European Economic Area Agreement, Romania and Norway have developed a project for monitoring the quality of raw and potable water (from production technology until distribution) supplied by two Romanian water companies. In the present study was investigated the microbiological quality of water, which was compared with organic matter loads. Resulting free chlorine and trihalomethane compounds after disinfection processes were also analysed. The raw water collected from Danube hydrographical basin showed significant pollution with potential pathogenic microorganisms with faecal origin such as Salmonella sp., Escherichia coli, Enterobacter sp., Klebsiella pneumoniae, Proteus mirabilis, Citrobacter braakii, Providencia stuartii, and Enterococcus sp. Also other bacteria such as Pseudomonas aeruginosa, Acinetobacter, total number of bacteria at 22 and 37 °C were detected, being related to high water oxidability. The microbial load was reduced considerably after the disinfection process. However, the total number of bacteria at 22 or 37 °C was constantly higher than the imposed limit and Clostridium perfringens was identified occasionally. The tap water presented a sporadic microbial loading with Enterococcus sp., Pseudomonas aeruginosa and E. coli and constantly with total number of bacteria due to an improper water distribution network.

Microbiological Control of UHT Sterilized Milk and Milk Products and Effects on Consumers' Health in Western Algeria

The present study focused on the analysis of microbiological quality of various milk samples such as ultra-high temperature sterilized milk (UHT), melted cheese and yoghurt, obtained from dairy product factories in western Algeria. Hazards identification and development of a quality management standard for these subsidiaries evidenced that the sanitary quality was satisfactory. The result revealed detection of faecal origin contamination ‘total and fecal coliforms’ in both the yoghurt product and sample of melted cheese where the average content was(1.29±6.72-0.14±0.56 x 103cfu/g) and (0.14±0.6-0.022±0.275 x 103cfu/g) respectively. It is indicative that all samples were free from Staphylococcus aureus and Salmonella sp. The study demonstrated that prerequisite programs (PRP) will prevent the occurrence of microbiological hazards origin, which confirms the fact that hygiene measures are the best safety assurance. The hazard analysis of the production process of yoghurt and cheese allowed us to find out their causes, adoption of preventive measures for certain sensitive stages where hazards can be eliminated or reduced at acceptable levels, the determination of critical control points (CCP)and operational prerequisite programs ‘PRPo’, implementing critical limits, and monitoring plans. DOI: http://dx.doi.org/10.3329/mh.v3i1.19777 Microbes and Health, June 2014. 3(1): 21-24

Protozoan predation is differentially affected by motility of enteric pathogens in water vs. sediments.

Survival of enteric bacteria in aquatic habitats varies depending upon species, strain, and environmental pressures, but the mechanisms governing their fate are poorly understood. Although predation by protozoa is a known, top-down control mechanism on bacterial populations, its influence on the survival of fecal-derived pathogens has not been systematically studied. We hypothesized that motility, a variable trait among pathogens, can influence predation rates and bacterial survival. We compared the survival of two motile pathogens of fecal origin by culturing Escherichia coli O157 and Salmonella enterica Typhimurium. Each species had a motile and non-motile counterpart and was cultured in outdoor microcosms with protozoan predators (Tetrahymena pyriformis) present or absent. Motility had a significant, positive effect on S. enterica levels in water and sediment in the presence or absence of predators. In contrast, motility had a significant negative effect on E. coli O157 levels in sediment, but did not affect water column levels. The presence/absence of protozoa consistently accounted for a greater proportion of the variability in bacterial levels (>95 %) than in bacterial motility (<4 %) in the water column. In sediments, however, motility was more important than predation for both bacteria. Calculations of total CFU/microcosm showed decreasing bacterial concentrations over time under all conditions except for S. enterica in the absence of predation, which increased ∼0.5-1.0 log over 5 days. These findings underscore the complexity of predicting the survival of enteric microorganisms in aquatic habitats, which has implications for the accuracy of risk assessment and modeling of water quality.

Bacteriocin-encoding genes and ExPEC virulence determinants are associated in human fecal Escherichia coli strains.

BackgroundA set of 1181 E. coli strains of human fecal origin isolated in the South Moravia region of the Czech Republic was collected during the years 2007–2010. Altogether, 17 virulence determinants and 31 bacteriocin-encoding genes were tested in each of them.ResultsThe occurrence of bacteriocin-encoding genes was found to be positively correlated with the occurrence of E. coli virulence factors. Based on the presence of virulence factors and their combinations, E. coli strains were classified as non-pathogenic E. coli (n = 399), diarrhea-associated E. coli (n = 179) and ExPEC strains (n = 603). Non-pathogenic and diarrhea-associated E. coli strains had a low frequency of bacteriocinogeny (32.6% and 36.9%, respectively). ExPEC strains encoding S-fimbriae (sfa), P-fimbriae (pap) and having genes for aerobactin biosynthesis (aer, iucC), α-hemolysis (α-hly) and cytotoxic necrosis factor (cnf1) were often bacteriocinogenic (73.8%), had a high prevalence of bacteriocin multi-producers and showed a higher frequency of genes encoding microcins H47, M, V, B17 and colicins E1, Ia and S4.ConclusionsThe occurrence of bacteriocin-encoding genes and ExPEC virulence determinants correlate positively in E. coli strains of human fecal origin. Bacteriocin synthesis appears to modulate the ability of E. coli strains to reside in the human intestine and/or the virulence of the corresponding strains.

Research on Food Manufacturing with S-Layer Protein of Selected &lt;i&gt;Lactobacillus&lt;/i&gt; is Responsible for Competitive Exclusion against Human Enteropathogens

In this study, five selected Lactobacillus of fecal origin were investigated for their probiotic properties. They were preliminarily identified by partial 16S rDNA gene sequencing and characterized in vitro for their resistance to low pH and bile salts. Here, we assessed the adhesive properties and the ability to inhibit the adhesion and to displace pathogens of five selected Lactobacillus strains using HT-29 cells model through a process which may be related to specific components of the baterial surface. Surface-layer proteins are located in a paracrystalline layer outside the bacterial cell wall and are thought to play a role in tissue adherence. Removal of S-layer proteins from the Lactobacillus (treated with 5 M LiCl) reduced adhesion to Caco-2 cells. Under such conditions, inhibition activity was also decreased in all five strains, as revealed in competition assays, which suggested that S-layer protein had involved in the adhesion of probiotics. SDS-PAGE analysis confirmed the presence of S-layer proteins with dominant bands of was approximately 60 kDa. Our findings also indicate that the surface layer proteins contributed to its increased adhesion to the cultured cells and competitive exclusion of pathogens.

Complete Genome Sequence of Enterococcus mundtii QU 25, an Efficient L-(+)-Lactic Acid-Producing Bacterium

Enterococcus mundtii QU 25, a non-dairy bacterial strain of ovine faecal origin, can ferment both cellobiose and xylose to produce l-lactic acid. The use of this strain is highly desirable for economical l-lactate production from renewable biomass substrates. Genome sequence determination is necessary for the genetic improvement of this strain. We report the complete genome sequence of strain QU 25, primarily determined using Pacific Biosciences sequencing technology. The E. mundtii QU 25 genome comprises a 3 022 186-bp single circular chromosome (GC content, 38.6%) and five circular plasmids: pQY182, pQY082, pQY039, pQY024, and pQY003. In all, 2900 protein-coding sequences, 63 tRNA genes, and 6 rRNA operons were predicted in the QU 25 chromosome. Plasmid pQY024 harbours genes for mundticin production. We found that strain QU 25 produces a bacteriocin, suggesting that mundticin-encoded genes on plasmid pQY024 were functional. For lactic acid fermentation, two gene clusters were identified—one involved in the initial metabolism of xylose and uptake of pentose and the second containing genes for the pentose phosphate pathway and uptake of related sugars. This is the first complete genome sequence of an E. mundtii strain. The data provide insights into lactate production in this bacterium and its evolution among enterococci.

Niveles de resistencia a quinolonas y otros antimicrobianos en cepas de Escherichia coli comensales en niños de la zona periurbana de Lima, Perú

The main aim of this study was to establish the resistance levels to antimicrobial agents, in 222 non-pathogenic E. Coli strains of fecal origin in Peru. The proportion of resistance found to the evaluated antimicrobials was ampicillin (62.6%), cotrimoxazole (48,6%), tetracycline (43,0%) and chloramphenicol (15,8%). We emphasize the high resistance levels found for quinolones: 32% for nalidixic acid (NAL) and 12% for ciprofloxacin (CIP). These high levels of quinoloneresistance in non-pathogenic strains isolated from children in this age group highlight the extensive use and the impact of the intake of this kind of antimicrobials in the community, showing the potential risk of the loss of their utility in the area.

Evaluation of cellular immune response provoked by experimental infection with Cryptosporidium spp. in mice

Experimental infection was induced in immunosupreesed and non-immunosupressed mice using inoculation of two different Cryptosporidium spp. isolates: faecal origin and river water origin; then the infectivity rate and cellular immunological status were examined in these groups of mice. The results indicated that these two isolates induced experimental infection in immunosuppressed and non-immunosuppressed mice with no significant differences in infectivity rate between groups. Immunosuppressed mice infected with feacal or water origin oocyst showed low and significant values of transformed lymphocytes 8.68% ± 0.65%, 9.18% ± 1.09 respectively and phagocytic index 10.1% ± 1.66 and 11.2% ± 0.19 respectively. It concludes that lymphocyte transformation and phagocytosis index are good indicators to evaluate the cellular immune response in infected experimental mice with Cryptosporidium.

Antimicrobial Susceptibility of Escherichia coli Isolated from Fresh-Marketed Nile Tilapia (Oreochromis niloticus).

The contamination of seafood by bacteria of fecal origin, especially Escherichia coli, is a widely documented sanitary problem. The objective of the present study was to isolate E. coli strains from the gills, muscle, and body surface of farmed Nile tilapias (Oreochromis niloticus) fresh-marketed in supermarkets in Fortaleza (Ceará, Brazil), to determine their susceptibility to antibiotics of different families (amikacin, gentamicin, imipenem, cephalothin, cefotaxime, ciprofloxacin, aztreonam, ampicillin, nalidixic acid, tetracycline, and sulfametoxazol-trimetoprim), and to determine the nature of resistance by plasmid curing. Forty-four strains (body surface = 25, gills = 15, muscle = 4) were isolated, all of which were susceptible to amikacin, aztreonam, cefotaxime, ciprofloxacin, gentamicin, and imipenem. Gill and body surface samples yielded 11 isolates resistant to ampicillin, tetracycline, and sulfametoxazol-trimetoprim, 4 of which of plasmidial nature. The multiple antibiotic resistance index was higher for strains isolated from body surface than from gills. The overall high antibiotic susceptibility of E. coli strains isolated from fresh-marketed tilapia was satisfactory, although the occasional finding of plasmidial resistance points to the need for close microbiological surveillance of the farming, handling, and marketing conditions of aquaculture products.

Health risks of water wells in the Moorish baths: correlation between pathogenic bacteria and determination of gradients of contamination

The emergence of pathogens in water cold of baths Moors served by wells have been chlorinated or not, is a major concern in terms of the public health industry and the public authorities concerned. Among these pathogens, some are of fecal origin (Escherichia coli, intestinal enterococci, anaerobic sulphite-reducing or Clostridia), while others live in the natural environment (Staphylococcus aureus, and Pseudomonas aeruginosa). In order to establish a risk analysis related to the presence of these pathogens, it is important to increase our knowledge on the ecology of these microorganisms and to develop analytical tools to achieve better health monitoring. In total 568 samples sanitary cold water during the four seasons, to evaluate by PCA (Principal Component Analysis) the bacteriological quality of pathogens and to define spatiotemporal and seasonal gradients of contamination. Thus, could be determined three groups of bacteriological contamination (i) Gr1 well Moorish baths which is moving towards a contamination by fecal indicators (E. coli, intestinal enterococci, anaerobic sulphite-reducing); (ii) Gr 2 wells Moorish baths which is moving towards a contamination with P. aeruginosa; (iii) Gr 3 wells Moorish baths which is moving towards a contamination by S. aureus. Also, a seasonal gradient of correlation between these pathogens increases slightly in the winter, spring and summer to autumn.

Virulence profiles of Shiga toxin-producing Escherichia coli and other potentially diarrheagenic E.coli of bovine origin, in Mendoza, Argentina

This study described a group of strains obtained from a slaughter house in Mendoza, in terms of their pathogenic factors, serotype, antibiotype and molecular profile. Ninety one rectal swabs and one hundred eight plating samples taken from carcasses of healthy cattle intended for meat consumption were analyzed. Both the swab and the plate samples were processed to analyze the samples for the presence of virulence genes by PCR: stx1, stx2, eae and astA. The Stx positive strains were confirmed by citotoxicity assay in Vero cells. The isolates were subsequently investigated for their O:H serotype, antimicrobial susceptibility and molecular profile by Random Amplification of Polymorphic DNA (RAPD). Twelve E.coli strains were identified by their pathogenicity. Nine were from fecal origin and three from carcasses. Three strains carried the stx1 gene, three the stx2 gene, two carried eae and four the astA gene. The detected serotypes were: O172:H-; O150:H8; O91:H21; O178:H19 and O2:H5. The strains showed a similarity around 70% by RAPD. Some of the E.coli strains belonged to serogroups known for certain life-threatening diseases in humans. Their presence in carcasses indicates the high probability of bacterial spread during slaughter and processing.

Enteric bacteria in Olrog’s Gull (Larus atlanticus) and Kelp Gull (Larus dominicanus) from the Bahía Blanca Estuary, Argentina

The Bahía Blanca Estuary in Argentina is under the effect of chronic microbiological pollution with untreated raw sewage and the pathogens associated with it. In this estuary, there are breeding colonies of Olrog’s Gull (Larus atlanticus) and Kelp Gull (Larus dominicanus), where parents feed chicks and themselves on prey and food items foraged at or near sewage outfalls and refuse tips where they can be exposed to pathogens of human and animal origin. The objective of this study was to assess the role of Olrog’s Gull and Kelp Gull as carriers of zoonotic pathogens of faecal origin. Bacterial recovery from faecal samples of both gull species was positive for Salmonella enterica var. Typhimurium, Salmonella enterica var. Gallinarum, Escherichia coli, Shigella dysenteriae, Enterobacter cloacae and Klebsiella pneumoniae. The prevalence and diversity of pathogens varied between gull species, and Olrog’s Gull tested positive for a wider range of pathogens than Kelp Gull. Escherichia coli was the most prevalent bacteria in chicks and adults of both gull species, followed by Salmonella spp. in Olrog’s Gull chicks, and Enterobacter cloacae and Shigella dysenteriae in Olrog’s Gull adults. The potential use of these gull species as sentinels of microbiological pollution in the Bahía Blanca Estuary is proposed.

Rapid genetic detection of ingested Amanita phalloides

Mushrooms are often poorly digested by humans. Thus, their remains (tissues, spores) may persist in the gastrointestinal tract and can be detected in feces several days after mushroom consumption. In this report, we present protocols for the rapid PCR-based detection of fungal traces in a variety of complex samples. Novel primers were designed to amplify portions of ribosomal DNA from deadly poisonous European members of the genus Amanita, namely the death cap (A. phalloides), the destroying angel (A. virosa) and the fool's mushroom (A. verna), respectively. Assay sensitivity was sufficient to discover diluted DNA traces in amounts below the genomic content of a single target mushroom cell. Specificity testing was performed with DNA extracts from a variety of mushroom species. Template amplification was exclusively observed with intended targets and it was not compromised by a vast excess of non-target DNA (i.e. DNA from human and human fecal origin, respectively). A series of experiments was conducted with prepared specimens in order to follow the course of mushroom food processing and digestion. Amplification by direct PCR was successful with raw, fried and digested mixed mushrooms. To improve assay performance with fecal samples, a rapid protocol for sample pre-processing (including water-ether sedimentation and bead beating) and a modified PCR reaction mix were applied. Thereby, it was possible to detect the presence of A. phalloides DNA in spiked feces as well as in clinical samples (vomit, stool) from two independent cases of suspected mushroom poisoning.

IS30-related transposon mediated insertional inactivation of bile salt hydrolase (bsh1) gene of Lactobacillus plantarum strain Lp20

Lactobacillus plantarum is a flexible and versatile microorganism that inhabits a variety of niches, and its genome may express up to four bsh genes to maximize its survival in the mammalian gut. However, the ecological significance of multiple bsh genes in L. plantarum is still not clearly understood. Hence, this study demonstrated the disruption of bile salt hydrolase (bsh1) gene due to the insertion of a transposable element in L. plantarum Lp20 – a wild strain of human fecal origin. Surprisingly, L. plantarum strain Lp20 produced a ∼2.0kb bsh1 amplicon against the normal size (∼1.0kb) bsh1 amplicon of Bsh+L. plantarum Lp21. Strain Lp20 exhibited minimal Bsh activity in spite of having intact bsh2, bsh3 and bsh4 genes in its genome and hence had a Bsh− phenotype. Cloning and sequence characterization of Lp20 bsh1 gene predicted four individual open reading frames (ORFs) within this region. BLAST analysis of ORF1 and ORF2 revealed significant sequence similarity to the L. plantarum bsh1 gene while ORF3 and ORF4 showed high sequence homology to IS30-family transposases. Since, IS30-related transposon element was inserted within Lp20 bsh1 gene in reverse orientation (3′–5′), it introduced several stop codons and disrupted the protein reading frames of both Bsh1 and transposase. Inverted terminal repeats (GGCAGATTG) of transposon, mediated its insertion at 255–263nt and 1301–1309nt positions of Lp20 bsh1 gene. In conclusion, insertion of IS30 related-transposon within the bsh1 gene sequence of L. plantarum strain Lp20 demolished the integrity and functionality of Bsh1 enzyme. Additionally, this transposon DNA sequence remains active among various Lactobacillus spp. and hence harbors the potential to be explored in the development of efficient insertion mutagenesis system.

Microbiological findings of vulvovaginitis in prepubertal girls

ObjectiveTo compare vaginal culture results between prepubertal girls with and without vulvovaginitis, and obtain an overview of the most commonly encountered microbes.DesignProspective descriptive study.SettingOutpatient clinic of Vilnius University Hospital Santariskiu...