Role of the oral microbiota in cancer evolution and progression.

Bacteria identified in the oral cavity are highly complicated. They include approximately 1000 species with a diverse variety of commensal microbes that play crucial roles in the health status of individuals. Epidemiological studies related to molecular pathology have revealed that there is a close relationship between oral microbiota and tumor occurrence. Oral microbiota has attracted considerable attention for its role in in-situ or distant tumor progression. Anaerobic oral bacteria with potential pathogenic abilities, especially Fusobacterium nucleatum and Porphyromonas gingivalis, are well studied and have close relationships with various types of carcinomas. Some aerobic bacteria such as Parvimonas are also linked to tumorigenesis. Moreover, human papillomavirus, oral fungi, and parasites are closely associated with oropharyngeal carcinoma. Microbial dysbiosis, colonization, and translocation of oral microbiota are necessary for implementation of carcinogenic functions. Various underlying mechanisms of oral microbiota-induced carcinogenesis have been reported including excessive inflammatory reaction, immunosuppression of host, promotion of malignant transformation, antiapoptotic activity, and secretion of carcinogens. In this review, we have systemically described the impact of oral microbial abnormalities on carcinogenesis and the future directions in this field for bringing in new ideas for effective prevention of tumors.

Adhesion of anaerobic periodontal pathogens to extracellular matrix proteins.

Extracellular matrix (ECM) proteins are highly abundant in the human body and can be found in various tissues, most prominently in connective tissue and basement membrane. For invasive bacterial pathogens, these structures function as physical barriers that block access to underlying tissues. The ability to bind and degrade these barriers is important for the establishment of infections and migration to other body sites. In the oral cavity, the ECM and the basement membrane (BM) are important components of the Junctional epithelium (JE) that closes the gap between the teeth surface and the mucosa. In periodontitis, the JE is breached by invading pathogenic bacteria, particularly strict anaerobic species. In periodontitis, invading microorganisms induce an unregulated and destructive host response through polymicrobial synergism and dysbiosis that attracts immune cells and contributes to the destruction of connective tissue and bone in the periodontal pocket. Colonization of the periodontal pocket is the first step to establish this infection, and binding to ECM is a major advantage in this site. Several species of strict anaerobic bacteria are implicated in acute and chronic periodontitis, and although binding to ECM proteins was studied in these species, few adhesins were identified so far, and the mechanisms involved in adhesion are largely unidentified. This review summarizes the data available on the interaction of strict anaerobic bacteria and components of the ECM.

Utility of anaerobic bottles for the diagnosis of bloodstream infections.

BACKGROUND: Obligate anaerobes usually account for less than 10% of bacteria recovered from blood cultures (BC). The relevance of routine use of the anaerobic bottle is under debate. The aim of this study was to evaluate the utility of anaerobic bottles for the diagnosis of bloodstream infections (BSI). METHODS: We conducted a 6-month, retrospective, monocentric study in a tertiary hospital. All positive BC were grouped into a single episode of bacteremia when drawn within 7 consecutive days. Bacteremia were classified into contaminants and BSI. Charts of patients with BSI due to obligate anaerobes were studied. RESULTS: A total of 19,739 blood cultures were collected, 2341 of which (11.9%) were positive. Anaerobic bottles were positive in 1528 (65.3%) of all positive BC but were positive alone (aerobic bottles negative) in 369 (15.8%). Overall 1081 episodes of bacteremia were identified, of which 209 (19.3%) had positive anaerobic bottles alone. The majority 126/209 (60.3%) were contaminants and 83 (39.7%) were BSI. BSI due to facultative anaerobes, obligate aerobes and obligate anaerobes were identified in 67 (80.7%), 3 (3.6%) and 13 (15.7%) of these 83 episodes, respectively. BSI due to obligate anaerobic bacteria were reported in 9 patients with gastro-intestinal disease, in 3 with febrile neutropenia and in 1 burned patient. CONCLUSIONS: Anaerobic bottles contributed to the diagnosis of a significant number of episodes of bacteremia. Isolated bacteria were mostly contaminants and non-obligate anaerobic pathogens. Rare BSI due to obligate anaerobes were reported mainly in patients with gastro-intestinal disorders and during febrile neutropenia.

Antimicrobial resistance in pathogenic aerobic bacteria causing surgical site infections in Mbarara regional referral hospital, Southwestern Uganda.

Surgical site infections (SSI) remain a common postoperative complication despite use of prophylactic antibiotics and other preventive measures, mainly due to increasing antimicrobial resistance. Here, we present antimicrobial resistance rate of bacteria isolated in clinical cases of SSI. A hospital based descriptive cross sectional study was conducted on 83 consented postoperative patients with clinical SSI. Data on patients was obtained using structured data collection form. Two swabs were collected aseptically from each patient. Bacteriological culture examination and identification was done following standard microbiological techniques. Antibiotic susceptibility test was done by Kirby-Bauer disc diffusion method. Gram negative bacteria (GNB) were predominant (65.59%) with the dominant being Klebsiella species (29.03%). Overall 86% of aerobic bacteria isolated were multidrug resistant (MDR) where 65.63% and 96.72% of Gram positive and Gram negative isolates were MDR respectively. All the isolates with exception of Enterococci species were resistant to ampicillin. GNB showed high resistance to ceftriaxone, sulfamethoxazole/trimethoprim and gentamicin. All the isolated Klebsiella spp were MDR. S. aureus were all resistant to oxacillin. The isolation rate was higher in emergency, males and dirty wounds in relation to nature of surgery, gender and class of surgical wound respectively. These findings necessitate judicious antibiotic use and calls for surveillance of SSIs periodically as well as strict adherence to good sanitation practice to reduce spread of drug-resistant pathogens.

[The species variety of microflora in samples from urogenital tract of female patients of large network laboratory and its dependence of content of lactobaccilli].

The evaluation of content of DNA of lactobaccilli and particular types of aerobic anaerobic opportunistic bacteria in sampling of scrapes from urogenital tract offemale patients of the network laboratory INVITRO was implemented. The technique of polymerase chain reaction in real-time was implemented. It is demonstrated that decreasing of content of lactobaccilli in total bacterial mass isfollowed by increasing of occurrence, concentration and relative content of all types of opportunistic pathogens except ureaplasmna. These changes are expressed in different degree for different types of opportunistic pathogens. The increasing of varieties of types of microflora of urogenital tract under decreasing of content of lactobaccilli is noted.

[Contamination of human milk with aerobic flora: Evaluation of losses for a human milk bank]. / Contamination du lait maternel par une flore aérobie : évaluation des pertes pour un lactarium.

INTRODUCTION: In France, human milk banks pasteurize milk for the mother's own hospitalized baby (personalized milk) and for donation. There is specific legislation regulating the activity of human milk banks with bacterial screening of donor milk before and after pasteurization. Milk should be tested for Staphylococcus aureus and total aerobic flora. Any sample of milk positive for aerobic flora and/or S. aureus before and/or after pasteurization should be discarded. The real pathogenicity of the total aerobic flora is actually debated as well as the usefulness of systematic postpasteurization screening. The aim of this study was to quantify milk losses related to prepasteurization contamination by total aerobic flora in a regional milk bank, to identify losses due to contamination with S. aureus or aerobic flora, and to analyze differences between centers. METHODS: This was a prospective observational study conducted in the regional human milk bank of the Nord-Pas-de-Calais area in France. Data were collected from six major centers providing 80% of the milk collected between June 2011 and June 2012. Variables were the volumes of personalized milk collected by each center, volumes of contaminated milk, and the type of bacteria identified. RESULTS: During the study period, the regional human milk bank treated 4715 L (liters) of personalized milk and 508 L (10.8%) were discarded due to bacteriological screening. Among these 508 L, 43% were discarded because of a prepasteurization contamination with aerobic flora, 55% because of a prepasteurization contamination with S. aureus, and 2% because of other pathogenic bacteria. Postpasteurization tests were positive in 25 samples (0.5%). Only five of these 25 samples were positive before pasteurization and in all cases with S. aureus. A total of 218 L were destroyed because of prepasteurization contamination with total aerobic flora, while the postpasteurization culture was sterile. There was a great difference between centers in the percentage of discarded milk and the type of contamination. The percentage of discarded milk varied from 4 to 16% (P<0.001) and the percentage of prepasteurization positive samples with aerobic flora from 0 to 70% (P<0.001). Costing 80 €/L in France, this represented an economic loss of €17,440. CONCLUSION: A significant volume of milk is discarded because of contamination with total aerobic flora found only in prepasteurization tests. Reassessment of the French regulations with regard to microbiological safety could save human milk to cover the needs of a larger group of preterm babies.

Microorganisms of the toe web and their importance for erysipelas of the leg.

BACKGROUND: There has been a steady increase of the incidence of erysipelas in Germany in the recent past. Affected patients also often show defects in the cutaneous barrier caused by microorganisms. The aim of this non-interventional case-control study was to investigate a possible interrelationship between interdigital tinea pedis and bacterial toe web (interdigital space) infections and erysipelas of the leg, as well as a potential interaction among the microorganisms themselves. MATERIAL AND METHODS: The patient population contained 150 people equally distributed among three groups, one retrospective and one prospective erysipelas group (EG = rEG + pEG) plus one control group (KG). RESULTS: 51 % of the patients with erysipelas and 32 % of the control group suffered from interdigital tinea pedis. There was a significant association between interdigital tinea pedis and the recurrence rate of erysipelas, but not with erysipelas itself. Staphylococcus aureus (EG: 30.34 %; KG: 3.23 %) and non-pathogenic aerobic bacteria were significantly associated with erysipelas in each statistical analysis. Staphylococcus aureus showed a positive, the non-pathogenic aerobic germs (EG: 28,09 %; KG: 80,65 %) a negative association. CONCLUSIONS: This study demonstrates an association between the microorganisms of the toe web and erysipelas of the leg. Erysipelas itself is influenced to a great extent by the bacterial flora, while its recurrence relates more to interdigital tinea pedis.

Refrigerated poultry breast fillets packed in modified atmosphere and irradiated: bacteriological evaluation, shelf life and sensory acceptance

In the present study the effects on shelf life and sensory acceptance of gamma-irradiated refrigerated poultry breast fillets subjected to modified atmosphere packaging (80% CO2/20% N2 or vacuum) were investigated. After irradiation with 2 kGy, sensory acceptance tests and monitoring of bacterial growth were performed in order to determine the sanitary quality of the samples. It has been found that irradiation, used in combination with modified atmosphere packaging, can double the shelf life of refrigerated poultry breast fillets by reducing the populations of aerobic mesophilic and psychrotrophic bacteria, enterobacteria, coliforms, Listeria spp. and Aeromonas spp., without significantly modifying its color or its overall appearance, the lactic acid bacteria being the most resistant to exposure to radiation and carbon dioxide.

The prevalence of overgrowth by aerobic bacteria in the small intestine by small bowel culture: relationship with irritable bowel syndrome.

OBJECTIVES: Many studies have linked irritable bowel syndrome (IBS) with small intestinal bacterial overgrowth (SIBO), although they have done so on a qualitative basis using breath tests even though quantitative cultures are the hallmark of diagnosis. The purpose of this study was to underscore the frequency of SIBO in a large number of Greeks necessitating upper gastrointestinal (GI) tract endoscopy by using quantitative microbiological assessment of the duodenal aspirate. METHODS: Consecutive subjects presenting for upper GI endoscopy were eligible to participate. Quantitative culture of aspirates sampled from the third part of the duodenum during upper GI tract endoscopy was conducted under aerobic conditions. IBS was defined by Rome II criteria. RESULTS: Among 320 subjects enrolled, SIBO was diagnosed in 62 (19.4%); 42 of 62 had IBS (67.7%). SIBO was found in 37.5% of IBS sufferers. SIBO was found in 60% of IBS patients with predominant diarrhea compared with 27.3% without diarrhea (P = 0.004). Escherichia coli, Enterococcus spp and Klebsiella pneumoniae were the most common isolates within patients with SIBO. A step-wise logistic regression analysis revealed that IBS, history of type 2 diabetes mellitus and intake of proton pump inhibitors were independently and positively linked with SIBO; gastritis was protective against SIBO. CONCLUSIONS: Using culture of the small bowel, SIBO by aerobe bacteria is independently linked with IBS. These results reinforce results of clinical trials evidencing a therapeutic role of non-absorbable antibiotics for the management of IBS symptoms.

Adipose tissue depots of Holstein cows are immune responsive: inflammatory gene expression in vitro.

The transcriptional response of adipose tissue depots with respect to their immune responsiveness in dairy cows remains largely unknown. Thus, we examined mRNA expression and responsiveness of subcutaneous (SUB) and mesenteric (MES) adipose tissue from nonpregnant dairy cows to a short-term (2 h), in vitro lipopolysaccharide (LPS) challenge (20 microg/mL in physiological saline). Abundance of mRNA for tumor necrosis factor-alpha (TNFA), interleukin-6 (IL6), serum amyloid A3 (SAA3), toll-like receptor 4 (TLR4), monocyte chemoattractant protein-1 (CCL2), and RANTES/chemokine C-C motif ligand 5 (CCL5) were analyzed using quantitative polymerase chain reaction (PCR) from tissue samples collected at slaughter from 5 nonpregnant/nonlactating Holstein cows. Prior to LPS challenge, SAA3 mRNA abundance was greater in MES than SUB tissue. Regardless of depot site, LPS led to greater mRNA abundance of TNFA and IL6 and was more pronounced for IL6 in MES. We also observed a marked increased in expression of CCL2, CCL5, TLR4, IL6, and TNFA in both MES and SUB during the 2-h incubation with saline alone (ie, the control). Because mRNA expression of the apoptotic markers B-cell CLL/lymphoma 2 (BCL2) and tumor protein p53 (TP53) did not differ during the 2-h incubation, it is less likely that the response to saline was a result of increased rate of cell death during incubation. Analysis using semiquantitative PCR of the 16s rRNA gene in cDNA from tissue explants revealed the presence of bacteria likely arising from contamination during sample collection. Furthermore, surfactant medium from about 50% of explant cultures had viable aerobic bacteria without differences between treatments or tissue samples. Thus, the presence of bacteria could partly explain the large increase in inflammatory-related genes after 2-h incubation with saline. The higher SAA3 expression in MES suggests that this acute-phase protein has a role in lipid metabolism and/or transport during an immune challenge. Overall, results provided evidence that adipose depots of dairy cows are capable of synthesizing chemokines and are immune responsive when exposed to inflammatory conditions that can arise from a pathogenic insult or during and soon after parturition.

Microbiology and management of abdominal infections.

This review describes the microbiology, diagnosis, and management of intra-abdominal infections. These infections include secondary peritonitis, abdominal abscesses, and cholangitis. The infection generally occurs because enteric microorganisms enter the peritoneal cavity through a defect in the wall of the intestine or other viscus as a result of obstruction, infarction, or direct trauma. Mixed aerobic and anaerobic flora can be recovered. The predominant aerobic isolates are Escherichia coli, etc. The aerobic isolates are Escherichia coli, and enterococci, and the main anaerobic bacteria are Bacteroides fragilis group Peptostreptococcus spp. and Clostridium spp. The treatment of abdominal infection includes surgical correction and drainage of pus and administration of antimicrobials effective against both the aerobic and anaerobic pathogens.

Microbiology of peritonsillar abscess as an indication for tonsillectomy.

No conclusive data are available regarding the influence of the microbial content of a peritonsillar abscess (PTA) on the development of recurrence. We conducted the current study to evaluate the effect of microbiologic growth on the recurrence rate of PTA and the need for tonsillectomy. Of 469 patients with PTA, 295 patients who underwent bacteriologic studies were subdivided into 2 groups, nonrecurrent group (273 patients) and recurrent group (22 patients), and their results were compared. A higher rate of anaerobic growth (10 anaerobic pathogens, 57.1% of total pathogens found) was identified in the recurrent PTA group compared with the nonrecurrent group (39 anaerobic pathogens, 45.8%), with a higher rate of anaerobic growth in the recurrent group in the first episode (60% vs. 45.8% in the nonrecurrent group) (odds ratio, 1.76; sensitivity, 80%; specificity, 45%). Anaerobic bacterial growth correlates with a higher rate of recurrence, and may serve as an additional relative indicator for tonsillectomy.

Comparative antimicrobial susceptibility of aerobic and facultative bacteria from community-acquired bacteremia to ertapenem in Taiwan.

BACKGROUND: Ertapenem is a once-a-day carbapenem and has excellent activity against many gram-positive and gram-negative aerobic, facultative, and anaerobic bacteria. The susceptibility of isolates of community-acquired bacteremia to ertapenem has not been reported yet. The present study assesses the in vitro activity of ertapenem against aerobic and facultative bacterial pathogens isolated from patients with community-acquired bacteremia by determining and comparing the MICs of cefepime, cefoxitin, ceftazidime, ceftriaxone, ertapenem, piperacillin, piperacillin-tazobactam, ciprofloxacin, amikacin and gentamicin. The prevalence of extended broad spectrum beta-lactamases (ESBL) producing strains of community-acquired bacteremia and their susceptibility to these antibiotics are investigated. METHODS: Aerobic and facultative bacteria isolated from blood obtained from hospitalized patients with community-acquired bacteremia within 48 hours of admission between August 1, 2004 and September 30, 2004 in Chang Gung Memorial Hospital at Keelung, Taiwan, were identified using standard procedures. Antimicrobial susceptibility was evaluated by Etest according to the standard guidelines provided by the manufacturer and document M100-S16 Performance Standards of the Clinical Laboratory of Standard Institute. Antimicrobial agents including cefepime, cefoxitin, ceftazidime, ceftriaxone, ertapenem, piperacillin, piperacillin-tazobactam, ciprofloxacin, amikacin and gentamicin were used against the bacterial isolates to test their MICs as determined by Etest. For Staphylococcus aureus isolates, MICs of oxacillin were also tested by Etest to differentiate oxacillin-sensitive and oxacillin-resistant S. aureus. RESULTS: Ertapenem was highly active in vitro against many aerobic and facultative bacterial pathogens commonly recovered from patients with community-acquired bacteremia (128/159, 80.5 %). Ertapenem had more potent activity than ceftriaxone, piperacillin-tazobactam, or ciprofloxacin against oxacillin-susceptible S. aureus (17/17, 100%)and was more active than any of these agents against enterobacteriaceae (82/82, 100%). CONCLUSION: Based on the microbiology pattern of community-acquired bacteremia, initial empiric treatment that requires coverage of a broad spectrum of both gram-negative and gram-positive aerobic bacteria, such as ertapenem, may be justified in moderately severe cases of community-acquired bacteremia in non-immunocompromised hosts.

[Bioaerosol concentrations and the identification of aerosolized bacteria by 16S rDNA analysis in work environments].

Bioaerosols cause sick building syndrome (SBS) and allergy. Many kinds of bioaerosol impactors are used for measurement of airborne microorganism concentrations in Japan. However, because the impactors are set on agar plates, some microorganisms cannot make colonies on the plates because of their lower viability or demands of nutrition. On the other hand, by double staining using ethidium bromide (EtBr) and carboxyfluorescein diacetate (CFDA), both total cells and cells with esterase activities can be detected without incubation. In this study, we calculated total cell concentrations and percentages of cells with esterase activities by the combination of filter sampling and double staining (EtBr and CFDA) from air of a laboratory, a conference room and outdoors. Temperature and humidity in the laboratory were constantly kept by an air conditioner, but in the conference room, an air conditioner was only operated sometimes because of its low frequency of use. There were no significant differences between total cell concentrations and humidity in both rooms, but increase of the percentages of cells with esterase activities depended on rainfall before the samplings (n=15, p<0.05 by Mann-Whitney test). The increase of active microorganisms by rainfall should be considered when we evaluate the risk of bioaerosols in the workplace. There were few differences in classifications of aerosolized bacteria by 16S rDNA sequence-based homology between the laboratory and the conference room. In both rooms, few pathogenic bacteria were observed.

Evaluating empiric treatment options for secondary peritonitis using pharmacodynamic profiling.

BACKGROUND: Selecting an appropriate agent for empiric antibiotic therapy for secondary peritonitis is challenging. The pathogens responsible, aerobic gram-negative bacilli in particular, are becoming more resistant to antibiotics. The purpose of this study was to predict the ability of common antimicrobial regimens to achieve optimal pharmacodynamic exposure against aerobic bacteria implicated in secondary peritonitis, while considering current national resistance trends. METHODS: Monte Carlo simulation was used to model pharmacodynamic endpoints and compare the cumulative fraction of response (CFR) for imipenem-cilastatin, meropenem, ertapenem, piperacillin/tazobactam, ceftazidime, ceftriaxone, ciprofloxacin, and levofloxacin against isolates of species associated with secondary peritonitis. Minimum inhibitory concentration (MIC) distributions for isolates collected in North America were obtained from the 2004 MYSTIC database. Pharmacokinetic parameters were derived from the literature; the endpoints evaluated included free drug time above the MIC (fT(>MIC)) and the area under the concentration-time curve to MIC ratio (AUC:MIC). RESULTS: The simulation predicted that several compounds would have a superior probability of providing appropriate coverage of aerobic bacteria: Imipenem-cilastatin (98.6% CFR at 1 g q8h), meropenem (98.2% CFR at 1 g q8h), ertapenem (91.7% CFR at 1 g q24h), piperacillin/ tazobactam (93.7% CFR at 3.375 g q6h), ceftazidime (91.1% CFR at 2 g q8h), and cefepime (92.9% CFR at 1 g q12h and 95.8% CFR at 2 g q12h). Ceftriaxone, ciprofloxacin, and levofloxacin exhibited CFRs < 82%. CONCLUSIONS: Considering contemporary susceptibility data for aerobic bacteria, monotherapy with any of the three carbapenems or piperacillin/tazobactam 3.375 g q6h would provide optimal exposure for the pathogens commonly encountered in secondary peritonitis. Cefepime (in combination with metronidazole to provide anti-anaerobic coverage) also would be an acceptable choice, as would ceftazidime given at 2 g q8h (again in combination with metronidazole). Despite the popularity of combination therapy based on ciprofloxacin, levofloxacin, or ceftriaxone with metronidazole, these choices appear to be inferior to the other options because of emerging antibiotic resistance, particularly in E. coli.

Distribution, diversity and ecology of aerobic CO-oxidizing bacteria.

Numerous studies indicate that carbon monoxide (CO) participates in a broader range of processes than any other single molecule, ranging from subcellular to planetary scales. Despite its toxicity to many organisms, a diverse group of bacteria that span multiple phylogenetic lineages metabolize CO. These bacteria are globally distributed and include pathogens, plant symbionts and biogeochemically important lineages in soils and the oceans. New molecular and isolation techniques, as well as genome sequencing, have greatly expanded our knowledge of the diversity of CO oxidizers. Here, we present a newly emerging picture of the distribution, diversity and ecology of aerobic CO-oxidizing bacteria.

[Opisthorchiasis in the Ob-Irtysh river basin: etiology and pathogenesis].

Opisthorchiasis in the hyperendemic focus (Ob-Irtysh river basin) is considered to be a co-member of parasitocenosis: opisthorchiasis + methorchiasis and to have a superinvasive form. The symbiotic flora and O. felines metabolites are an etiopathogenetic flora. Scientific evidence is provided for the recurrent forms ofopisthorchiasis; the authors consider it to be the type of superinvasive opisthorchiasis, in which some portion of parasites in microballs unexposed to antheminthics further mature to maritae.