Explorative study on mucosal and major salivary secretion rates, caries and plaque microflora in head and neck cancer patients.

OBJECTIVE: To analyse mucosal and major salivary secretion rates, caries and plaque microflora in connection with treatment for cancer in the head and neck region. METHODS: Thirty-three patients were included and the number of teeth, filled surfaces and caries lesions registered. The labial and buccal gland secretion and stimulated whole salivary secretion rates were determined. Supragingival plaque microflora was analysed using cultivation technique. Data were collected pretreatment, during treatment and 6 months, 1 year and 2 years post-treatment. RESULTS: Two years post-treatment, 36% had new caries lesions, which had been restored. The labial secretion was comparable with pretreatment, while the buccal secretion was lower (P < .001). The stimulated secretion rate was lower compared with pretreatment (P < .001) and was ≤0.7 mL/minute for 50%. Growth of lactobacilli increased during treatment (P < .001) and remained increased (P < .001), while growth of mutans streptococci was decreased (P < .01) 2 years post-treatment. Growth of Candida increased over time and was higher 2 years post-treatment compared with pretreatment (P < .001) while growth of Prevotella was lower (P < .01). CONCLUSIONS: Two years post-treatment, the stimulated salivary secretion rate was substantially decreased, acid-tolerant lactobacilli and Candida increased, acid-sensitive microorganisms decreased, and the caries prevalence was low.

Colonic inflammation accompanies an increase of ß-catenin signaling and Lachnospiraceae/Streptococcaceae bacteria in the hind gut of high-fat diet-fed mice.

Consumption of an obesigenic/high-fat diet (HFD) is associated with a high colon cancer risk and may alter the gut microbiota. To test the hypothesis that long-term high-fat (HF) feeding accelerates inflammatory process and changes gut microbiome composition, C57BL/6 mice were fed HFD (45% energy) or a low-fat (LF) diet (10% energy) for 36 weeks. At the end of the study, body weights in the HF group were 35% greater than those in the LF group. These changes were associated with dramatic increases in body fat composition, inflammatory cell infiltration, inducible nitric oxide synthase protein concentration and cell proliferation marker (Ki67) in ileum and colon. Similarly, ß-catenin expression was increased in colon (but not ileum). Consistent with gut inflammation phenotype, we also found that plasma leptin, interleukin 6 and tumor necrosis factor α concentrations were also elevated in mice fed the HFD, indicative of chronic inflammation. Fecal DNA was extracted and the V1-V3 hypervariable region of the microbial 16S rRNA gene was amplified using primers suitable for 454 pyrosequencing. Compared to the LF group, the HF group had high proportions of bacteria from the family Lachnospiraceae/Streptococcaceae, which is known to be involved in the development of metabolic disorders, diabetes and colon cancer. Taken together, our data demonstrate, for the first time, that long-term HF consumption not only increases inflammatory status but also accompanies an increase of colonic ß-catenin signaling and Lachnospiraceae/Streptococcaceae bacteria in the hind gut of C57BL/6 mice.

Study of enteropathogenic bacteria in children with acute diarrhoea aged from 7 to 10 years in Xuzhou, China.

BACKGROUND: Acute diarrhoea is a common infectious disease among children in many countries and it has different kinds of clinical symptoms including vomiting, abdominal cramps, or fever of 38 °C. Some specific intestinal bacteria and their quantities can result in relevant symptoms. AIM: To analyze the correspondence between enteropathogenic bacteria and acute diarrhoea at family-level using high-throughput sequencing approach. METHODS: Every 30 children of acute diarrhoea with abdominal cramps, vomiting, and fever of 38 °C was regarded as a group, respectively. Stools samples were collected from each group and the DNA of stool was examined by E.Z.N.A.(®) Stool DNA Kit. The 16S rRNA genes sequencing was performed on an Illumina Miseq platform. FINDINGS: The sequencing dataset comprised 65,092 valid reads sequences that affiliated to the 18 phylogenetic families. The four dominant taxonomic groups in all three samples were Streptococcaceae, Veillonellaceae, Enterobacteriaceae and Lactobacillaceae. The stools of children with high fever presented higher pathogenic bacterial diversities and more complex community structures than other two groups. Lactobacillaceae was the enteric predominant microflora that could reduce the severity of acute diarrhoea. CONCLUSION: The reduction of predominant microflora or the aberrant proliferation of sub-dominant microflora can break the intestinal operation mechanism and cause intestinal diseases. What's more, people's living habits are also correlative about acute diarrhoea and parents should prepare light food for their children in order to protect their tender gastrointestinal mucosa.

Water quality in turkey farms in Khemisset (Morocco) and potential risk factors. / Qualité des eaux en élevage de dinde à Khémisset (Maroc) et hypothèses sur les facteurs de risques.

The objectives of this study were to assess the microbiological and physical/chemical quality of water in broiler turkey farms in the province of Khemisset (north-western Morocco) and, based on a questionnaire, to ascertain potential risk factors for contamination of drinking water with faecal coliforms. A total of 80 samples were collected and analysed in 20 farms (four from each farm). At the main inlet to the water line at the entrance to each turkey house, 100% of the samples were of unacceptable quality in terms of faecal coliforms, Escherichia coli, faecal streptococci, sulphitereducing anaerobes and enterococci. A significant reduction in microbiological contamination of the water line (p < 0.05) was observed on Day 60. While more than 90% of the samples were of satisfactory quality in terms of pH, nitrites, conductivity, nitrates and iron, only 35% were satisfactory in terms of total hardness and only 20% met quality standards for ammonium content. The factors affecting levels of contamination with faecal coliforms were water chlorination (p = 0.065; odds ratio = 14; 90% confidence interval [CI] = 1.14-71), cleaning and disinfection (p = 0.028; odds ratio = 14; 95% CI = 1.25-156.6) and antibiotic treatment (p = 0.001; odds ratio = 6; 95% CI = 2.1-35.2). To improve water quality in poultry farms, farmers are advised to protect wells from contamination and to install water purification units (pre-oxidation, coagulation, flocculation, disinfection). In addition, turkey houses and rearing equipment should be rigorously cleaned and disinfected between each batch of birds.

Cette étude a pour objectifs d'évaluer la qualité microbiologique et physico-chimique de l'eau des élevages de dinde de chair dans la province de Khémisset (nord-ouest du Maroc) et de formuler, au moyen d'un questionnaire, certaines hypothèses sur les facteurs de risque potentiels associés à la contamination de l'eau d'abreuvement par les coliformes fécaux. Au total, 80 échantillons ont été prélevés et analysés dans 20 élevages (quatre de chaque élevage). Au sas de la ligne d'abreuvement, 100 % des échantillons étaient de qualité inacceptable en ce qui concerne les coliformes fécaux, Escherichia coli, les streptocoques fécaux, les anaérobies sulfito-réducteurs et les entérocoques. Une réduction significative de la contamination microbiologique a été observée en bout de la ligne d'abreuvement (p < 0,05) au jour 60. Plus de 90 % des échantillons étaient de qualité satisfaisante pour ce qui concerne le pH, les nitrites, la conductivité, les nitrates et le fer ; en revanche, seulement 35 % et 20 % d'échantillons étaient conformes pour ce qui concerne la dureté totale et la présence d'ammonium, respectivement. Les facteurs associés à la contamination par les coliformes fécaux étaient la chloration de l'eau (p = 0,065 ; rapport des cotes = 14 ; intervalle de confiance [IC] à 90 % = 1,14-71), le nettoyage et la désinfection (p = 0,028 ; rapport des cotes = 14 ; IC à 95 % = 1,25-156,6) et le traitement par antibiotiques (p = 0,001 ; rapport des cotes = 6 ; IC à 95 % = 2,1-35,2). Afin d'améliorer la qualité de l'eau dans les élevages avicoles, il est recommandé aux éleveurs de protéger les puits contre la contamination et d'installer des stations de potabilisation de l'eau (pré-oxydation, coagulation, floculation, désinfection). Il convient également de procéder à un nettoyage et une désinfection rigoureux des bâtiments et du matériel d'élevage à la fin de chaque bande.

Los autores describen un estudio destinado a evaluar la calidad microbiológica y fisicoquímica del agua de explotaciones productoras de pavos de engorde de la provincia de Khemisset (noroeste de Marruecos) y a formular, mediante un cuestionario, ciertas hipótesis sobre los posibles factores de riesgo asociados a la contaminación del agua de bebida por coliformes fecales. En total se tomaron y analizaron 80 muestras de 20 explotaciones. En la esclusa de entrada del agua en la línea de bebederos, el 100% de las muestras era de calidad inaceptable por lo que respecta a la presencia de coliformes fecales, Escherichia coli, estreptococos fecales, bacterias anaerobias sulfitorreductoras y enterococos. A la salida de la línea de bebederos se observaba una reducción significativa de la contaminación microbiológica (p < 0,05) en el día 60. Más del 90% de las muestras eran de calidad satisfactoria por lo que respecta a pH, nitritos, conductividad, nitratos y hierro. En cambio, solo un 35% y un 20% de las muestras satisfacían los criterios relativos a la dureza total y la presencia de amonio, respectivamente. Los factores asociados a la contaminación por coliformes fecales eran la cloración del agua (p = 0,065; razón de probabilidades = 14; intervalo de confianza [IC] al 90% = 1,14-71), la limpieza y desinfección (p = 0,028; razón de probabilidades = 14; IC al 95% = 1,25-156,6) y el tratamiento con antibióticos (p = 0,001; razón de probabilidades = 6; IC al 95% = 2,1-35,2). Con el fin de mejorar la calidad del agua en las explotaciones avícolas se recomienda a los productores que protejan los pozos de la contaminación e instalen potabilizadoras de agua (preoxidación, coagulación, floculación y desinfección). Asimismo, conviene proceder a una limpieza y una desinfección rigurosas de los locales y el material de cría al final de cada banda.

Evaluation of the bacteriological quality of raw cow's milk at various stages of the milk production chain on farms in Algeria. © OIE (World Organisation for Animal Health), 2016. / Évaluation de la qualité bactériologique du lait cru bovin à divers stades de la chaîne de production laitière dans des fermes en Algérie.

This study evaluates hygiene practices on 53 dairy farms in the Jijel and Blida regions of Algeria. A survey questionnaire was drawn up covering milking conditions and cleaning of the equipment. In parallel, bacteriological analyses were carried out to estimate the rate, source and development of bacterial contamination in raw milk produced on the farm. In addition, screening was performed to detect the presence of inhibitor residues. The results of the survey revealed poor livestock conditions and milking practices that could explain the presence of bacteria in cow's milk. The bacteriological results showed that 76.1% of milk samples taken from cow udders complied with legal standards, compared with only 35.8% of milk samples taken from storage tanks. Moreover, bacterial inhibitors were detected in 28.8% of milk samples. These results showed that the hands of milkers, udders, teat cups, utensils, the water used during milking and the milking environment were all potential sources of milk contamination by the bacteria under investigation. These results suggest that, to improve the bacteriological quality of milk, there is a need to introduce a quality policy which places a premium on milk of high bacteriological quality and aims to generalise good hygiene practices throughout the dairy production chain.

La présente étude consiste à évaluer les pratiques d'hygiène instaurées dans 53 exploitations bovines laitières réparties dans les régions de Jijel et de Blida en Algérie. Pour cela, un questionnaire d'enquête a été élaboré, portant sur les conditions de la traite et sur le nettoyage du matériel utilisé. En parallèle, des analyses bactériologiques ont été effectuées afin d'estimer le taux, l'origine et l'évolution de la contamination bactérienne du lait cru produit à la ferme. En outre, des recherches ont été effectuées pour déceler la présence de résidus d'inhibiteurs. Les résultats de l'enquête ont mis en évidence les mauvaises conditions d'élevage et des pratiques de la traite qui peuvent expliquer la présence de bactéries dans le lait de vache. Les résultats bactériologiques ont montré que 76,1 % des échantillons de lait prélevé au pis des vaches étaient conformes aux critères légaux, contre 35,8 % seulement des échantillons de lait provenant des cuves de stockage. De plus, la présence d'inhibiteurs bactériens a été décelée dans 28,8 % des échantillons de lait. Ces résultats ont permis de déterminer que les mains des trayeurs, les mamelles, les gobelets trayeurs, les ustensiles, l'eau et l'environnement de la traite étaient les sources potentielles de contamination du lait par les bactéries recherchées. À la lumière de ces résultats, l'amélioration de la qualité bactériologique du lait repose sur l'instauration d'une politique de qualité, visant à vulgariser les bonnes pratiques d'hygiène tout au long de la chaîne de production laitière et à mettre en place une prime à la qualité bactériologique du lait.

Los autores exponen un estudio destinado a evaluar las prácticas de higiene empleadas en 53 explotaciones bovinas lecheras de las regiones de Jijel y Blida (Argelia). Para ello se elaboró un cuestionario relativo a las condiciones de ordeño y a la limpieza del material utilizado. Paralelamente se realizaron análisis bacteriológicos con el fin de estimar la tasa, el origen y la evolución de la contaminación bacteriana de la leche cruda producida en cada explotación. Además, se efectuaron investigaciones para detectar la presencia de residuos de inhibidores. Los resultados de la investigación pusieron de manifiesto que las condiciones de cría y las prácticas de ordeño eran inadecuadas, lo que puede explicar la presencia de bacterias en la leche de vaca. Los resultados bacteriológicos evidenciaron que un 76,1 % de las muestras de leche tomadas en la ubre de las vacas cumplían los criterios legales, por solo un 35,8 % de las muestras procedentes de las cubas de almacenamiento. Por otro lado, se detectó la presencia de inhibidores bacterianos en un 28,8 % de las muestras de leche. Estos resultados sirvieron para determinar que las posibles fuentes de contaminación de la leche por las bacterias investigadas se encontraban en las manos de los ordeñadores, las ubres, los cubos de ordeño, los utensilios empleados, el agua y el espacio en que discurría el ordeño. A tenor de los resultados, la mejora de la calidad bacteriológica de la leche pasa por la aplicación de una política de calidad, que sirva para divulgar las prácticas idóneas de higiene en toda la cadena de producción lechera y para instituir una prima a la calidad bacteriológica de la leche.

Physicochemical and microbiological characterization of cement kiln dust for potential reuse in wastewater treatment.

Cement kiln dust (CKD), a byproduct of cement manufacturing process, was collected from Misr Cement Co. at Qena, Egypt. CKD was characterized by X-ray diffraction and FTIR analysis. This byproduct was investigated for its physical-chemical characters, antibacterial activities on sewage water and the presence of nematode, parasites and algae in the treated water. The efficiency of CKD-treated water was also examined on Hibiscus sabdarriffa seed germination. Total bacteria, total and fecal coliform, as well as fecal streptococci were completely inhibited by CKD. Interestingly, zinc, manganese, iron, nickel and lead were completely absent from sewage water as these metals precipitated after treatment with 10gl(-1) CKD. On the other hand, among all the tested plant criteria, only root length was significantly reduced by 55% and 15% after zero and 3 days of CKD addition respectively compared to control. Furthermore, plant lipid peroxidation showed no significant differences between treated sewage water and control after zero and 3 days time addition of CKD. Catalase enzyme activity showed significant decrease by 56% and 64%, while peroxidase activity significantly increased up to 49% and 63% compared to untreated sewage after zero and 3 days of treatment, respectively. The absorption of lead, iron and copper by treated and untreated plants showed no significant differences. Chromium ions were highly absorbed (0.075mgl(-1)) by plants irrigated only with treated sewage water at zero time, and decreased gradually to 0.018mgl(-1) after 3 days of CKD addition. This study highlighted the efficiency of cement kiln dust as an antibacterial agent and its ability of scavenging heavy metals leading to the use of treated sewage water in activities such as crop irrigation.

Survey of canine tick-borne diseases in Lábrea, Brazilian Amazon: ‘accidental’ findings of Dirofilaria immitis infection / Pesquisa de agentes transmitidos por carrapatos em cães de Lábrea, Amazonas: achados “acidentais” de Dirofilaria immitis

Blood samples were collected from 99 domestic dogs from the urban and rural areas of the Lábrea municipality, state of Amazonas, Brazil. Canine serum samples were tested by immunofluorescence assay against Rickettsia spp., which revealed that only 3.0% (1/33) and 7.6% (5/66) of the dogs from urban and rural areas, respectively, reacted positively to at least one Rickettsia species. DNA was extracted from canine blood and tested by a battery of PCR assays targeting protozoa of the genera Babesia and Hepatozoon, and bacteria of the genera Rickettsia and Ehrlichia and family Anaplasmataceae. All samples were negative in the PCR assays targeting the genera Babesia, Hepatozoon, Ehrlichia and Rickettsia. For Anaplasmataceae, 3% (1/33) and 39.4% (26/66) of the urban and rural dogs, respectively, yielded amplicons that generated DNA sequences 100% identical to the corresponding sequence of Wolbachia endosymbiont of Dirofilaria immitis. Because of these results, all canine DNA samples were further tested in a PCR assay targeting filarial nematodes, which was positive for 18.2% (6/33) and 57.6% (38/66) urban and rural dogs, respectively. Filarial-PCR products generated DNA sequences 100% identical to D. immitis. While tick-borne infections were rare in Lábrea, D. immitis infection rates were among the highest reported in South America.

Amostras de sangue foram coletadas de 99 cães domésticos de áreas urbana e rural do município de Lábrea, estado do Amazonas. Soros caninos foram testados pela técnica de imunofluorescência indireta contra Rickettsia spp., resultando em apenas 3,0% (1/33) e 7,6% (5/66) de cães soropositivos nas áreas urbana e rural, respectivamente. DNA foi extraído do sangue canino e testado por diferentes protocolos da PCR para detecção de protozoários dos gêneros Babesia e Hepatozoon, e bactérias dos gêneros Rickettsia e Ehrlichia e da família Anaplasmataceae. Todas as amostras foram negativas nos protocolos de PCR para os gêneros Babesia, Hepatozoon, Ehrlichia e Rickettsia. Para Anaplasmataceae, 3% (1/33) e 39,4% (26/66) dos cães de áreas urbana e rural, respectivamente, geraram sequências de DNA 100% idênticas ao endosimbionte Wolbachia de Dirofilaria immitis. Posteriormente, as amostras foram testadas pela PCR para nematódeos filarídeos, resultando em 18,2% (6/33) e 57,6% (38/66) de amostras positivas nas áreas urbana e rural, respectivamente. Os produtos geraram sequências de DNA 100% idênticas a D. immitis. Em contraste com várias outras regiões do Brasil, infecções transmitidas por carrapatos foram raras em Lábrea. Por outro lado, as frequências de infecção por D. immitis estiveram entre as mais altas relatadas na América do Sul.

The visualization of biofilms in chronic diabetic foot wounds using routine diagnostic microscopy methods.

Diabetic foot wounds are commonly colonised by taxonomically diverse microbial communities and may additionally be infected with specific pathogens. Since biofilms are demonstrably less susceptible to antimicrobial agents than are planktonic bacteria, and may be present in chronic wounds, there is increasing interest in their aetiological role. In the current investigation, the presence of structured microbial assemblages in chronic diabetic foot wounds is demonstrated using several visualization methods. Debridement samples, collected from the foot wounds of diabetic patients, were histologically sectioned and examined using bright-field, fluorescence, and environmental scanning electron microscopy and assessed by quantitative differential viable counting. All samples (n = 26) harboured bioburdens in excess of 5 log10 CFU/g. Microcolonies were identified in 4/4 samples by all three microscopy methods, although bright-field and fluorescence microscopy were more effective at highlighting putative biofilm morphology than ESEM. Results in this pilot study indicate that bacterial microcolonies and putative biofilm matrix can be visualized in chronic wounds using fluorescence microscopy and ESEM, but also using the simple Gram stain.

Group B streptococcus GAPDH is released upon cell lysis, associates with bacterial surface, and induces apoptosis in murine macrophages.

Glyceraldehyde 3-phosphate dehydrogenases (GAPDH) are cytoplasmic glycolytic enzymes that, despite lacking identifiable secretion signals, have been detected at the surface of several prokaryotic and eukaryotic organisms where they exhibit non-glycolytic functions including adhesion to host components. Group B Streptococcus (GBS) is a human commensal bacterium that has the capacity to cause life-threatening meningitis and septicemia in newborns. Electron microscopy and fluorescence-activated cell sorter (FACS) analysis demonstrated the surface localization of GAPDH in GBS. By addressing the question of GAPDH export to the cell surface of GBS strain NEM316 and isogenic mutant derivatives of our collection, we found that impaired GAPDH presence in the surface and supernatant of GBS was associated with a lower level of bacterial lysis. We also found that following GBS lysis, GAPDH can associate to the surface of many living bacteria. Finally, we provide evidence for a novel function of the secreted GAPDH as an inducer of apoptosis of murine macrophages.

Changes in psychrotrophic microbial populations during milk creaming to produce Grana Trentino cheese.

The aim of this study was to study the psychrotrophic microbiota developing during milk creaming of Grana Trentino cheese-making. 138 isolates from raw whole milk, cream and skim milk samples were screened by Randomly amplified polymorphic DNA PCR biotyping and representative strains of each biotype were characterised by partial 16S rRNA gene sequencing and enzymatic activity. Pseudomonadaceae were commonly isolated in cream samples while Streptococcaceae and Enterobacteriaceae in milk samples. Moraxellaceae and Flavobacteriaceae were found in both cream and milk samples. More than 80% of psychrotrophic isolates could grow at 37°C. All Flavobacteriaceae and half of Pseudomonadaceae biotypes displayed proteolytic activity on milk agar even at low temperatures such as 10°C. All Streptococcaceae and some of Enterobacteriaceae displayed acidifying activity and almost all Acinetobacter spp. (Moraxellaceae) displayed lipolytic activity towards tributyrin. Even if psychrotrophic bacteria is not the dominant microbial group in raw milk, their total number increases during creaming and becomes one of the most present group together with Lactic Acid Bacteria. Their enzymatic activities may be key players in determining milk quality for cheese making.

Antifungal activity of strains of lactic acid bacteria isolated from a semolina ecosystem against Penicillium roqueforti, Aspergillus niger and Endomyces fibuliger contaminating bakery products.

Thirty samples of Italian durum wheat semolina and whole durum wheat semolina, generally used for the production of Southern Italy's traditional breads, were subjected to microbiological analysis in order to explore their lactic acid bacteria (LAB) diversity and to find strains with antifungal activity. A total of 125 presumptive LAB isolates (Gram-positive and catalase-negative) were characterized by repetitive extragenic palindromic-PCR (REP-PCR) and sequence analysis of the 16S rRNA gene, leading to the identification of the following species: Weissella confusa, Weissella cibaria, Leuconostoc citreum, Leuconostoc mesenteroides, Lactococcus lactis, Lactobacillus rossiae and Lactobacillus plantarum. The REP-PCR results delineated 17 different patterns whose cluster analysis clearly differentiated W. cibaria from W. confusa isolates. Seventeen strains, each characterized by a different REP-PCR pattern, were screened for their antifungal properties. They were grown in a flour-based medium, comparable to a real food system, and the resulting fermentation products (FPs) were tested against fungal species generally contaminating bakery products, Aspergillus niger, Penicillium roqueforti and Endomyces fibuliger. The results of the study indicated a strong inhibitory activity - comparable to that obtained with the common preservative calcium propionate (0.3% w/v) - of ten LAB strains against the most widespread contaminant of bakery products, P. roqueforti. The screening also highlighted the unexplored antifungal activity of L. citreum, L. rossiae and W. cibaria (1 strain), which inhibited all fungal strains to the same or a higher extent compared with calcium propionate. The fermentation products of these three strains were characterized by low pH values, and a high content of lactic and acetic acids.

Effects of prebiotic oligosaccharides and trehalose on growth and production of bacteriocins by lactic acid bacteria.

AIMS: To investigate the effects of two prebiotics and trehalose on the production of bacteriocins. METHODS AND RESULTS: Four carbohydrates [dextrose, fructo-oligosaccharides (FOS), raffinose, and trehalose] were used as the sole carbon source in a simple broth. Five bacteriocin-producing strains of bacteria, including those producing nisin, enteriocin, and other bacteriocins, were used, and their inhibitory activities when grown on each carbohydrate were determined. The inhibitory activity assay was performed using the agar well diffusion method, and Lactobacillus sakei JCM 1,157(T) was used as the indicator strain. Effective enhancement of bacteriocin production was observed with FOS and trehalose incubation. CONCLUSIONS: The results suggest that FOS and trehalose can effectively enhance the production of the five kinds of bacteriocins evaluated in this study. SIGNIFICANCE AND IMPACT OF THE STUDY: This study offers useful information for not only a new application of FOS and trehalose, but also the potential improvement of food preservation.

A prospective, randomized, double-blind study of vaginal microflora and epithelium in women using a tampon with an apertured film cover compared with those in women using a commercial tampon with a cover of nonwoven fleece.

Healthy women with normal menstrual cycles were randomly assigned to use either a test tampon during cycle 1 and a reference tampon during cycle 2 or a reference tampon during cycle 1 and a test tampon during cycle 2. Tampons were identical except for their cover materials: apertured film for the test tampon and nonwoven fleece for the reference tampon. Product use was doubly blinded. Qualitative and quantitative analyses of vaginal cultures were done pre-, mid-, and postmenstrually for a broad panel of microorganisms, colposcopy was performed, and diary reports were collected; 101 of 105 enrolled subjects completed the study. Midmenstrual findings for a variety of organisms differed from pre- and postmenstrual observations whether subjects were using test or reference tampons. No statistically significant differences were noted in prevalence or colony counts at premenstrual versus mid- and postmenstrual visits for most microorganisms. Prevalences of Gardnerella and anaerobic gram-negative rods were significantly different between tampons at the premenstrual visit, when unusually low values were observed for the test and reference tampons, respectively. None of the changes or differences in microflora were considered to be clinically significant. It is noteworthy, however, that declines in the prevalence and abundance of Lactobacillus during the menstrual periods were less pronounced during the use of both test and reference tampons than those reported from previous studies. Colposcopy showed no abnormal findings with either tampon and no changes in vaginal or cervical epithelial integrity. Thus, all evidence from both microbiological and colposcopic evaluations indicates that the apertured film cover of the test tampon is as safe as the nonwoven cover of the reference tampon.

[Use of immobilized cells of bacteria in the process of purification of waste water containing chlorates and chromates].

Some regularities of immobilization of chlorate-reducing bacteria by various carriers and especially sewage treatment for chlorate and chromates by adhered bacteria have been studied. Most bacterial cells are immobilized during the first hour of contact with the carrier. The studied carriers, as to their ability to adsorb Aerococcus dechloraticans TGS-463 cells, may be arranged in the following sequence: porolon > claydite > glass broaches > maize stem > barley straw. The 12-24 hour culture Aerococcus dechloraticans TGS-463 expresses maximum ability to immobilization. The bacterial cell fastening on the carrier increases 2.1 times the reduction velocity for chlorates and 1.6 times that for chromates. The velocity of chlorates and chromates reduction by the culture factened on the carrier decreases in the due course of time, that requires the carrier regeneration.

Combined effect of high-pressure treatments and bacteriocin-producing lactic acid bacteria on inactivation of Escherichia coli O157:H7 in raw-milk cheese.

The effect of high-pressure (HP) treatments combined with bacteriocins of lactic acid bacteria (LAB) produced in situ on the survival of Escherichia coli O157:H7 in cheese was investigated. Cheeses were manufactured from raw milk inoculated with E. coli O157:H7 at approximately 10(5) CFU/ml. Seven different bacteriocin-producing LAB were added at approximately 10(6) CFU/ml as adjuncts to the starter. Cheeses were pressurized on day 2 or 50 at 300 MPa for 10 min or 500 MPa for 5 min, at 10 degrees C in both cases. After 60 days, E. coli O157:H7 counts in cheeses manufactured without bacteriocin-producing LAB and not pressurized were 5.1 log CFU/g. A higher inactivation of E. coli O157:H7 was achieved in cheeses without bacteriocin-producing LAB when 300 MPa was applied on day 50 (3.8-log-unit reduction) than if applied on day 2 (1.3-log-unit reduction). Application of 500 MPa eliminated E. coli O157:H7 in 60-day-old cheeses. Cheeses made with bacteriocin-producing LAB and not pressurized showed a slight reduction of the pathogen. Pressurization at 300 MPa on day 2 and addition of lacticin 481-, nisin A-, bacteriocin TAB 57-, or enterocin AS-48-producing LAB were synergistic and reduced E. coli O157:H7 counts to levels below 2 log units in 60-day-old cheeses. Pressurization at 300 MPa on day 50 and addition of nisin A-, bacteriocin TAB 57-, enterocin I-, or enterocin AS-48-producing LAB completely inactivated E. coli O157:H7 in 60-day-old cheeses. The application of reduced pressures combined with bacteriocin-producing LAB is a feasible procedure to improve cheese safety.

Characterization of mesentericin ST99, a bacteriocin produced by Leuconostoc mesenteroides subsp. dextranicum ST99 isolated from boza.

Lactic acid bacteria isolated from Boza, a cereal-fermented beverage from Belogratchik, Bulgaria, were screened for the production of bacteriocins. With the first screening, 13 of the 52 isolates inhibited the growth of Listeria innocua and Lactobacillus plantarum. The cell-free supernatant of one of these strains, classified as Leuconostoc mesenteroides subsp. dextranicum ST99, inhibited the growth of Bacillus subtilis, Enterococcus faecalis, several Lactobacillus spp., Lactococcus lactis subsp. cremoris, Listeria innocua, Listeria monocytogenes, Pediococcus pentosaceus, Staphylococcus aureus and Streptococcus thermophilus. Clostridium spp., Carnobacterium spp., L. mesenteroides and Gram-negative bacteria were not inhibited. Maximum antimicrobial activity, i.e. 6,400 arbitrary units (AU)/ml, was recorded in MRS broth after 24 h at 30 degrees C. Incubation in the presence of protease IV and pronase E resulted in loss of antimicrobial activity, confirming that growth inhibition was caused by a bacteriocin, designated here as mesentericin ST99. No loss in activity was recorded after treatment with alpha-amylase, SDS, Tween 20, Tween 80, urea, Triton X-100, N-laurylsarcosin, EDTA and phenylmethylsulfonylfluoride. Mesentericin ST99 remained active after 30 min at 121 degrees C and after 2 h of incubation at pH 2 to 12. Metabolically active cells of L. innocua treated with mesentericin ST99 did not undergo lysis. Mesentericin ST99 did not adhere to the cell surface of strain ST99. Precipitation with ammonium sulfate (70% saturation), followed by Sep-Pack C18 chromatography and reverse-phase HPLC on a C18 Nucleosil column yielded one antimicrobial peptide.

Thermal resistances and lactate and diacetate sensitivities of bacteria causing bologna discolouration.

This report describes the effects of heat, sodium lactate, and sodium diacetate on the viabilities of Weissella viridescens ATCC 12706, Aerococcus viridans MPL-1 and MPL-B, and Carnobacterium viridans ATCC BAA 336. The latter three organisms were isolated from commercial product and have previously been shown to produce green discolourations in cooked cured bologna. W. viridescens was heat resistant in beef bologna (D(60 degrees C)=14.7 min) but not in APT broth. A. viridans and C. viridans were much more sensitive to heat (D(60 degrees C) in beef bologna < or =1.3 min), indicating that these organisms were probably post-pasteurization contaminants. Sodium lactate (3.0%) alone or in combination with 0.3% sodium diacetate slowed the growth rate and reduced the final cell numbers of A. viridans and C. viridans in inoculated bologna. W. viridescens was only slightly affected by the combined antimicrobials. The combination of sodium lactate and sodium diacetate prevented A. viridans and C. viridans from affecting the colour of beef bologna. However, lactate and diacetate themselves reduced red colour, as measured by HunterLab colourimetry. HunterLab a values for fresh beef bologna were 13.4 (no antimicrobial added), 9.6 (3.0% sodium lactate), 8.0 (0.3% sodium diacetate), and 7.9 (3.0% sodium lactate + 0.3% sodium diacetate).

Rope-producing strains of Bacillus spp. from wheat bread and strategy for their control by lactic acid bacteria.

Two types of white wheat bread (high- and low-type loaves) were investigated for rope spoilage. Thirty of the 56 breads tested developed rope spoilage within 5 days; the high-type loaves were affected by rope spoilage more than the low-type loaves. Sixty-one Bacillus strains were isolated from ropy breads and were characterized on the basis of their phenotypic and genotypic traits. All of the isolates were identified as Bacillus subtilis by biochemical tests, but molecular assays (randomly amplified polymorphic DNA PCR assay, denaturing gradient gel electrophoresis analysis, and sequencing of the V3 region of 16S ribosomal DNA) revealed greater Bacillus species variety in ropy breads. In fact, besides strains of B. subtilis, Bacillus licheniformis, Bacillus cereus, and isolates of Bacillus clausii and Bacillus firmus were also identified. All of the ropy Bacillus isolates exhibited amylase activity, whereas only 32.4% of these isolates were able to produce ropiness in bread slices after treatment at 96 degrees C for 10 min. Strains of lactic acid bacteria previously isolated from sourdough were first selected for antirope activity on bread slices and then used as starters for bread-making experiments. Prevention of growth of approximately 10(4) rope-producing B. subtilis G1 spores per cm(2) on bread slices for more than 15 days was observed when heat-treated cultures of Lactobacillus plantarum E5 and Leuconostoc mesenteroides A27 were added. Growth of B. subtilis G1 occurred after 7 days in breads started with Saccharomyces cerevisiae T22, L. plantarum E5, and L. mesenteroides A27.

Serum concentration of Hakata antigen, a member of the ficolins, is linked with inhibition of Aerococcus viridans growth.

BACKGROUND: Hakata antigen (Hakata) is a novel serum glycoprotein that consists of collagen- and fibrinogen-like domains, similar to ficolin/p35. Our research suggested that serum Hakata may be a target of a polysaccharide (PSA) produced by Aerococcus viridans. METHODS: A. viridans was incubated with human plasma and Hakata-depleted plasma to examine Hakata binding and growth inhibition of A. viridans through binding with PSA. RESULTS: When A. viridans was mixed with human acid citrate dextrose-one (ACD-A) plasma, it pulled down Hakata complexed with mannose-binding lectin (MBL)-associated serine proteases 1 and 2 (MASP-1 and MASP-2). This complex had the potential for C4 deposition. Serum Hakata circulates as Hakata-MASPs complex in the blood and is proteolytically active. By mixing A. viridans with human plasma, we prepared a Hakata-depleted plasma, deficient in Hakata-MASPs complex. This plasma failed to inhibit A. viridans growth plasma, but does not inhibit Staphylococcus aureus, Yersinia enterocolitica and Escherichia coli. However, a decrease of growth inhibition of A. viridans in Hakata-depleted plasma could be restored by adding a Hakata-MASPs complex preparation in a dose-dependent manner. On the other hand, the Hakata-MASPs complex exhibited strong binding to A. viridans, but not to S. aureus, Y. enterocolitica and E. coli. CONCLUSIONS: The serum concentration of Hakata is linked with growth inhibition of A. viridans upon binding of Hakata via PSA.

The evaluation of mixtures of yeast and potato extracts in growth media for biomass production of lactic cultures.

The effectiveness of yeast extracts (YE) and potato extracts (PE) to promote growth of seven lactic cultures was evaluated by automated spectrophotometry (AS). Two aspects of the growth curve were analysed: (1) maximum biomass obtained (using ODmax) and (2) highest specific growth rate mu(max)) Eleven lots from the same PE-manufacturing process were examined for lot-to-lot variability. The ODmax values of three of the seven strains were significantly affected by lot source, but mu(max) was not significantly affected. The growth of bacteria was systematically lower in base medium containing 100% PE than in base medium containing 100% YE for both ODmax or mu(max) data, which could be related to the lower content in nitrogen-based compounds in PE. In AS assays, highest OD values for Lactobacillus casei EQ28, Lactobacillus rhamnosus R-011, Lactobacillus plantarum EQ12, and Streptococcus thermophilus R-083 were obtained with a mixture of PE and YE. Fermentations (2 L) were also carried out to determine the accuracy of AS to predict biomass levels obtained under fermentation trials. In these fermentations, replacement of 50% YE with PE was shown to enable good growth of S. thermophilus. With L. rhamnosus R-011, a high correlation (R2 = 0.95) was found between ODmax data obtained in the AS assays and that of the 2-L bioreactor when the same growth medium was used for both series of fermentations. However, AS was not as efficient when industrial media were used for the bioreactor assays. The relationship was still good for ODmax between AS data and that of the bioreactor data with L. rhamnosus R-011 in industrial LBS medium (R2 = 0.87), but was very poor with the S. thermophilus R-083 on Rosell #43 industrial medium (R2 = 0.33). Since PE cost 40% less than YE, there are strong economic advantages in considering such a partial replacement of YE by PE.