Mixed Microflora Research Articles

FEATURES OF INTENSIVE TREATMENT IN PATIENTS AFTER TRACHEOSTOMY

Objective: to enhance the efficiency of medical rehabilitation in patients who have undergone mechanical ventilation (MV) and tracheostomy in an intensive care unit through dynamic clinical, laboratory, endoscopic control and adequate therapy for detected pathology. A total of 120 intensive care unit patients who had undergone tracheostomy in different MV periods were examined. Subjects and methods. A total of 120 patients (76 men and 44 women) aged 15 to 78 years were examined in different MV periods. All the patients were operated on in intensive care units. The surgical techniques of tracheostomy were described; the clinical and endoscopic pattern of the laryngeal and tracheal mucosa in patients on MV was presented. The bacteria isolated from the patients on MV were typed; the cartilages of the anterior tracheal wall were pathomorphologically studied in different MV periods. Results. Microbiological examination indicated the predominance of the mixed microflora: Staphylococcus, Pseudomonas aeruginosa and Proteus. Intraoperative postmortem examination of the cartilages of the anterior tracheal wall was made in 30 patients in different MV periods who were noted to develop pathological changes in the laryngeal and tracheal mucosa and destructive and dystrophic alterations in the tracheal cartilage even if their intubation lasted as long as 3 days. Morphological examination of tracheal cartilages in patients who were on MV for 4 to 7 days revealed progressive destructive and dystrophic processes in peretracheal connective tissue, leukocyte accumulation, and focal bleeding. During intubation for more 7 days, there was partial death of the cartilage, its replacement by granulation tissue, and appearance of regions of sequestration of the dead cartilage. Endoscopic examination showed varying degrees of postintubation laryngeal and tracheal changes in all (n=120) the examinees. Conclusion. The performed treatment permitted decannulation of 111 patients; 16 patients underwent endoscopic intervention into the larynx and trachea; reconstructive operations followed by decannulaton were performed in 4 patients with postintubation laryngeal and tracheal stenosis; 5 patients with severe comorbidity remained to be chronic cannula carriers.

Experience with Polygynax used in the treatment of vulvovaginitis caused by the aerobic and mixed microflora

Experience with Polygynax used in the treatment of vulvovaginitis caused by the aerobic and mixed microflora

Enhanced biohydrogen production from beverage wastewater: process performance during various hydraulic retention times and their microbial insights

This study demonstrates the feasibility of continuous hydrogen production from beverage industrial wastewater (BW) in a continuously-stirred tank reactor (CSTR) using enriched mixed microflora (EMC) under mesophilic conditions.

Biohydrogen Production from Mushroom Cultivation Waste by Anaerobic Solid‐state Fermentation

AbstractMushroom cultivation waste (MCW) is a polypropylene bag stuffed with wood flour and nutrients for growing mushroom, which is a feasible feedstock for anaerobic biohydrogen production owing to its abundant availability, high organic and nutrient content. This study optimized the seed inoculum from various waste sludges (sewage sludge, cow dung and pig slurry), nutrient addition and operation conditions (moisture content and MCW powder particle size) for maximal biohydrogen production by solid‐state fermentation (SSF). SSF batch test was operated at a MCW 3 g total volatile solid (TVS)/L, temperature 55 °C and rotation speed of 15 rpm with a vertical rotative shaker. The peak hydrogen production performance of hydrogen production rate (HPR) 9.50 mol H2/kg‐d and hydrogen yield (HY) 0.29 mmol H2/g TVS) are obtained using sewage sludge 2 seed inoculum, nutrients addition, moisture content 70 % and particle size of 1.190∼0.590 mm. The results show that the MCW has the potential for hydrogen production by anaerobic mixed microflora using solid‐state fermentation. The bioenergy of 1842 kWh while using SSF to conver MCW to produce biohydrogen and it could reduce CO2 emission of 114–178 kg per year comparing using fossil fuel such as coal, fuel oil and natural gas.

Shiga Toxin-Producing Escherichia coli (STEC) in Fresh Produce--A Food Safety Dilemma.

Produce contains high levels of mixed microflora, including coliforms and Escherichia coli, but occasionally pathogens may also be present. Enterotoxigenic E. coli and Shigatoxin-producing E. coli (STEC) have been isolated from various produce types, especially spinach. The presence of STEC in produce is easily detected by PCR for the Shiga toxin (Stx) gene, stx, but this is insufficient for risk analysis. STEC comprises hundreds of serotypes that include known pathogenic serotypes and strains that do not appear to cause severe illness. Moreover, Stx without a binding factor like intimin (encoded by eae) is deemed to be insufficient to cause severe disease. Hence, risk analyses require testing for other virulence or serotype-specific genes. Multiplex PCR enables simultaneous testing of many targets, but, in a mixed flora sample, not all targets detected may be coming from the same cell. The need to isolate and confirm STEC in produce is critical, but it is time- and labor-intensive due to the complexity of the group. Studies showed that only a handful of STEC strains in produce have eae, and most belonged to recognized pathogenic serotypes so are of definite health risks. Several eae-negative strains belonged to serotypes O113:H21 and O91:H21 that historically have caused severe illness and may also be of concern. Most of the other STEC strains in produce, however, are only partially serotyped or are unremarkable serotypes carrying putative virulence factors, whose role in pathogenesis is uncertain, thus making it difficult to assess the health risks of these STEC strains.

Phenotypic, molecular and antimicrobial susceptibility assessment in isolates from chronic ulcers of cured leprosy patients: a case study in Southern Brazil.

BACKGROUND One of the most stigmatizing physical sequelaeof leprosy in cured patients is the development of chronic lower extremity ulcers. The bacterial diversity present in ulcers is considered one of the factors that can delay the healing process, as well as serve as a focus for severe secondary infections. OBJECTIVE To identify the microbiota and antimicrobial resistance profile of bacteria isolated from skin ulcers in patients cured of leprosy. METHODSAfter obtaining informed consent, material was collected from ulcers of 16 patients treated at the Outpatient Public Health Dermatology Clinic of Rio Grande do Sul and Hospital Colônia Itapuã. Sampleswere collected during dressing, and the material sent to the Microbiology Laboratory of the Federal University of Health Sciences of Porto Alegre for microbiological culture. Methicillin-resistant Staphylococcus aureus (MRSA) was characterized by two molecular methods, including detection of the mecA gene by PCR and SCCmecgene typing. RESULTS Cultures revealed microorganisms in all ulcers: Gram-negative bacilli in 80%, Gram-positive cocci in 63%, and mixed microflora in 36%. Staphylococcus aureus and Pseudomonas aeruginosa were the most prevalent bacteria. Assessment of the antimicrobial resistance profile was notable for the presence of MRSA. Molecular analysis of this isolate revealed presence of the mecA gene contained in a type IV staphylococcal cassette chromosome mec (SCCmec). CONCLUSIONS In patients with leprosy, laboratory culture of skin ulcers is essential for correct antibiotic selection and to control emerging pathogens, such as MRSA carrying SCCmec type IV.

Biohydrogen Production from Textile Wastewater by Mixed Microflora in an Intermittent‐flow, Stirred Tank Reactor: Effect of Feeding Frequency

AbstractAn intermittent‐flow, stirred tank reactor (IFSTR) was used to produce biohydrogen from textile wastewater (TW) by activated sludge. The IFSTR was operated at pH 5.5 under various feeding frequencies and TW concentrations. The first intermittent peak biogas production rate of 17.5 L biogas/L‐d and HPR of 10 L H2/L‐d were obtained at feeding frequency of 12 times/d with TW concentration of 33.1 g hexoses/L. Butyrate and acetate were the major soluble metabolites at peak HPR, whereas lactate and ethanol accumulation decreased the HPR. Close resemblance of bacterial communities in periods of peak HPR with hydrogen producer Clostridium butyricum was observed.

Fermentative Hydrogen Production from Carob Pod: A Typical Mediterranean Forest Fruit

The carob-tree (Ceratonica siliqua L.) grows in arid to semi-arid Mediterranean areas and adapts well to poor soils. Carob pod, the fruit of carob tree is a sugar-rich biomass which may theoretically be ideal for biofuel production. During this study, the potential of hydrogen production from carob pod was evaluated in an anaerobic continuous stirred tank bioreactor using mixed microflora. A carob pod extract consisting of soluble carbohydrates at a concentration of 42.6 g/L was obtained from a standard extraction process. The reactor was operated at a hydraulic retention time (HRT) of 36 and 18 h and an organic loading rate of 155.8 and 311.6 mmol glucose/L/days respectively. The results showed a maximum hydrogen production yield of 8.4 L H2 per kg of carob pod biomass or 0.43 mmol H2 per mmol glucose consumed at the HRT of 18 h. Butyric acid was found to be the dominant metabolic product at both examined HRTs while propionic acid production decreased as HRT decreased. The present work suggests that carob tree, an alternative dryland forest crop, can be utilized for the efficient production of biohydrogen.

Features of mucosal lesions of stomach and duodenum in children with chronic gastroduodenitis with different microflora content

Our aim was to reveale the features of histological mucosa with different composition of the microflora of stomach and duodenum in children with chronic gastroduodenitis. The study included 122 children with chronic gastroduodenitis from 5 to 17 years old. All patients underwent endoscopy with histology of biopsy specimens of gastric and duodenal mucosa in 94 patients and in 48 patients among them with morphometry of biological material. Identification of herpes simplex virus 1, 2 types, cytomegalovirus, human papilloma virus 16, 18 types, Helicobacterpylori was carried out using polymerase chain reaction in biopsies of gastroduodenal mucosa and gastric juice. Children with chronic gastroduodenitis depending on the identified microorganisms were divided into groups: 1st (n = 51)--without detectable microorganisms, 2nd (n = 28)--with associations of H. pylori and viruses, 3rd (n = 15)--only with viruses, 4th (n = 28)--with H. pylori. Thus, in patients with H. pylori inflammation was noted mainly in the antral mucosa and dystrophic changes--in the duodenal mucosa. In the presence of viruses the inflammation was expressed more in the fundal stomach and duodenum. When viral-bacterial associations were observed most pronounced inflammatory-dystrophic process was localized throughout the gastroduodenal mucosa. In children with chronic gastroduodenitis in the presence of bacterial, viral and mixed microflora in the stomach and duodenum identified characteristic histological features of the mucosa, manifested in a different localization and severity of inflammatory and dystrophic changes.

Acute Paraproctitis. Review of the Literature

Acute anal abscess remains the issue of the day of modern surgery, which is due to, in particular, its occurrence in 0.5% of the population, 0.5-4% of surgical and 10-50% of coloproctological patients. In the article, the analysis of the literature on the etiology, classification, clinical picture, diagnosis and treatment of acute anal abscess is performed. The review revealed that 98% of acute anal abscess is caused by mixed microflora - staphylococci, streptococci in combination with E. coli. The clinical picture of acute anal abscess depends on the localization of inflammation, the virulence of microflora and the immunoreactivity of the organism. Diagnostic methods of acute anal abscess are finger and bidigital rectal examination, anoscopy, rectal examination with a mirror and rectoromanoscopy. Endorectal electrical thermometry, ultrasonography, abscessography, chromoabscessography, computed tomography, magnetic resonance imaging and others can be used as well. Once the diagnosis of acute anal abscess is established, urgent surgical intervention must be performed, which consists of the incision and drainage of abscess with the possible elimination of the opening in the zone of the anal crypt. The postoperative management of patients with acute anal abscess may involve the use of ultrasound, laser, phototherapy, oxygen and ozone therapy, wound dialysis, hydrophonophoresis, multicomponent drugs and others. Thus, as the data in the literature reveals, many questions concerning the management of patients with acute anal abscess are not resolved to the full extent. This is evidenced by the development of inflammatory complications in 13-20%, relapses in 1.5-40%, anal sphincter deficiency in 1.5-27.9% of cases, which makes it worthwhile to continue research on developing new methods of treatments for acute anal abscess

Application of a packed bed reactor for the production of hydrogen from cheese whey permeate: Effect of organic loading rate

The production of H2 was studied using a packed bed reactor with polyurethane foam acting as support material. Experiments were performed using mixed microflora under non sterile conditions. The system was initially operated with synthetic wastewater as the sole substrate. Subsequently, cheese whey permeate was added to the system at varying organic loading rates (OLR). The performance of the reactor was evaluated by applying a continuous decrease in OLR. As a result, a significant decrease in H2 yields (HY) was observed with the decrease in OLR from 18.8 to 6.3 g chemical oxygen demand (COD)/L d. Microbial analysis demonstrated that the prevalence of non-hydrogen producers, Sporolactobacillus sp. and Prevotella, was the main reason for low HYs obtained. This behavior indicates that the fermentation under non-sterile conditions was favored by high concentrations of substrate by creating an adverse environment for nonhydrogen producer organisms.

Biohydrogen production from algal biomass (Anabaena sp. PCC 7120) cultivated in airlift photobioreactor

The present study deals with the optimization of pretreatment conditions followed by thermophilic dark fermentative hydrogen production using Anabaena PCC 7120 as substrate by mixed microflora. Different airlift photobioreactors with ratio of area of downcomer and riser (Ad/Ar) in range of 0.4–3.2 were considered. Maximum biomass concentration of 1.63 g L−1 in 9 d under light intensity of 120 μE m−2 s−1 was observed at Ad/Ar of 1.6. The mixing time of the reactors was inversely proportional to Ad/Ar. Maximal H2 production was found to be 1600 mL L−1 upon pretreatment with amylase followed by thermophilic fermentation for 24 h compared to other methods like sonication (200 mL L−1), autoclave (600 mL L−1) and HCl treatment (1230 mL L−1). The decrease of pH from 6.5 to 5.0 during fermentation was due to the accumulation of volatile fatty acids. Amylase pretreatment gave higher reducible sugar content of 7.6 g L−1 as compare to other pretreatments. Thermophilic fermentation of pretreated Anabaena biomass by mixed bacterial culture was found suitable for H2 production.

Effect of temperature and temperature shock on the stability of continuous cellulosic-hydrogen fermentation

Three continuous stirred tank reactors (CSTR) were operated under mesophilic (37 ± 1°C), thermophilic (55 ± 1°C) and hyper-thermophilic (80 ± 1°C) temperatures for 164 days to investigate the effect of temperature and temperature shock on the cellulosic-dark hydrogen fermentation by mixed microflora. During steady state condition, the sudden decreases in the fermentation temperature occurred twice in each condition for 24h. The results show that the 55 ± 1 and 80 ± 1°C presented stable hydrogen yields of 12.28 and 9.72 mmol/g cellulose, respectively. However, the 37 ± 1°C presented low hydrogen yield of 3.56 mmol/g cellulose and methane yield of 5.4 mmol/g cellulose. The reactor performance under 55 ± 1 or 80 ± 1°C appeared to be more resilient to the sudden decreases in the fermentation temperature than 37 ± 1°C. The experimental analysis results indicated that the changing in soluble by-products could explain the effect of temperature and temperature shock, and the thermophilic temperature is expected having a better economic performance for cellulosic-hydrogen fermentation.

Cellulosic hydrogen production and microbial community characterization in hyper-thermophilic continuous bioreactor

A continuous stirred tank reactor was used for the dark hydrogen fermentation of cellulose by mixed microflora at hyper-thermophilic temperature (70 ± 1 °C) for 240 days. A total of twenty six batch experiments were conducted to investigate the effect of temperature on the activity of cellulosic-hydrogen producing bacteria. The results show that the system reached a steady state condition after 90 days. A stable hydrogen yield of 7.07 ± 0.23 mmol H2/g cellulose was maintained for 150 days with acetate, butyrate, ethanol and propionate as main soluble byproducts. Analysis of 16S rRNA sequences showed that the cellulolytic bacteria were close to Thermoanaerobacterium genus. The cellulosic-hydrogen producing bacteria were able to utilize the cellulose or glucose within a wide range of fermentation temperatures (45–80 °C) to produce hydrogen. The activation energy for cellulose and glucose were estimated at 133.2 and 117.7 kJ/mol, respectively.

Response surface methodology to design a selective enrichment broth for rapid detection of Salmonella spp. by SYBR Green Ι real-time PCR

In order to meet dominant growth of Salmonella spp. in a composed system of five pathogens for accurate detection, designing an appropriate selective enrichment broth was clearly needed. First, we built a high-throughput assay procedure based on SYBR Green Ι real-time PCR, which possessed the necessary specificity for Salmonella spp., a good linear standard curve with typical R (2) value (0.9984) and high amplification efficiency (99.0 %). Further, for the larger target biomass in the mixed microflora, acarbose, LiCl and bile salt were selected to optimize their concentrations using response surface methodology (RSM). A central composite design was employed to collect the data and fit the response. A quadratic polynomial model was derived by computer simulation. Statistical analysis was carried out to explore the action and interaction of the variables on the response. In the end, a novel broth (Sal-5) was formulated to allow the efficient enrichment of Salmonella spp. and inhibit the growth of other tested strains. A detection platform was developed, including selective enrichment in Sal-5, DNA extraction by the boiling lysis method and real-time PCR test based on SYBR Green Ι. This work could extend the application of RSM and real-time PCR in the design of other selective enrichment media for common pathogens.

생물학적 수소생산을 위한 혐기성 연속 회분식 반응조(ASBR)의 장기운전 특성

Long term hydrogen production was investigated in an anaerobic sequencing batch reactor (ASBR) using mixed microflora. Glucose (about 8,250 mg/L) was used as a substrate for the ASBR operation under the condition of pH 5.5 and 37°C with mixing at 150 rpm. The experiment was carried out over a period of 160 days. Hydrogen yield was 0.8 mol H2/mol glucose with F/M ratio 2 at initial operation period. The hydrogen yield reached to maximum 2.6 mol H2/mol glucose at 80th day operation. However decreased hydrogen yield was observed after 80 days operation and eventually no hydrogen yield. Although well-known hydrogen producer Clostridium sp. was detected in the reactor by PCR-DGGE analysis, changed reactor operation was the major reason of the decreased hydrogen production, such as low F/M ratio of 0.5 and high propionic acid concentration 2,130 mg/L. Consequently the long period operation resulted in MLSS accumulation and then low F/M ration stimulating propionic acid formation which consumes hydrogen produced in the reactor.

Rhinosinusitis in children.

Rhinosinusitis is the inflammation of the mucous membranes of nose and paranasal sinus(es). 5–13% of upper respiratory tract infections in children complicate into acute rhinosinusitis. Though not life threatening, it profoundly affects child's school performance and sleep pattern. If untreated, it could progress to chronic rhinosinusitis (CRS). The pathogens involved in perpetuation of CRS consist of multidrug-resistant mixed microflora. CRS is challenging to manage and could further extend to cause eye or intracranial complications. In children, CRS diagnosis is often either missed or incomprehensive. Due to this, morbidity and strain on healthcare budget are tremendous. Flexible fiberoptic endoscopy has revolutionized management of CRS. Its utility in children is being increasingly recognized. Optimal management entails specific appropriate antimicrobials as well as treatment of underlying causes. The aim is to normalize sinus anatomy and physiology and regain normal mucociliary function and clearance.

Hydrogen and Methane Production, Energy Recovery, and Organic Matter Removal from Effluents in a Two-Stage Fermentative Process

This study evaluates the potential for using different effluents for simultaneous H(2) and CH(4) production in a two-stage batch fermentation process with mixed microflora. An appreciable amount of H(2) was produced from parboiled rice wastewater (23.9 mL g(-1) chemical oxygen demand [COD]) and vinasse (20.8 mL g(-1) COD), while other effluents supported CH(4) generation. The amount of CH(4) produced was minimum for sewage (46.3 mL g(-1) COD), followed by parboiled rice wastewater (115.5 mL g(-1) COD) and glycerol (180.1 mL g(-1) COD). The maximum amount of CH(4) was observed for vinasse (255.4 mL g(-1) COD). The total energy recovery from vinasse (10.4 kJ g(-1) COD) corresponded to the maximum COD reduction (74.7 %), followed by glycerol (70.38 %, 7.20 kJ g(-1) COD), parboiled rice wastewater (63.91 %, 4.92 kJ g(-1) COD), and sewage (51.11 %, 1.85 kJ g(-1) COD). The relatively high performance of vinasse in such comparisons could be attributed to the elevated concentrations of macronutrients contained in raw vinasse. The observations are based on kinetic parameters of H(2) and CH(4) production and global energy recovery of the process. These observations collectively suggest that organic-rich effluents can be deployed for energy recovery with sequential generation of H(2) and CH(4).

Influence of the surface temperature of packaging specimens on the inactivation of Bacillus spores by means of gaseous H2O2

To determine the influence of condensation as a function of the surface temperature of aseptic packaging, on the inactivation of Bacillus spores [Bacillus subtilis (DSM 347), B. subtilis SA22, Bacillus atrophaeus] having different surface properties by means of vaporized H(2) O(2). The packaging specimens inoculated with Bacillus spores were tempered and subsequently exposed to H(2) O(2) -vapour. During the exposure, surface temperature curves were measured and the spore survival was determined. Results showed that decreasing the initial surface temperature of the packaging specimens had a positive effect on the sporicidal activity of H(2) O(2) -vapour, where the effect was less pronounced for less hydrophilic spores. The surfaces of spores were characterized by means of the water contact angle. For starting surface temperatures below the dew point temperature of the sterilant gas, the condensation of highly concentrated liquid H(2) O(2) on the packaging surface accelerates the killing of the spores, while the inferior wettability of more hydrophobic spores compared to more hydrophilic ones diminishes the effect. Regarding industrial packaging sterilization, a mixed microflora has to be inactivated. Promoting the condensation of H(2) O(2) improves in general the killing of different species of spores, however, at various degrees depending on the wettability of spores.

Hydrogen fermentation using lactate as the sole carbon source: Solution for ‘blind spots’ in biofuel production

Lactate is not believed to be a suitable substrate for hydrogen fermentation, although glucose and starch are. To eliminate this ‘blind spot’ in hydrogen fermentation, we showed that it is feasible to produce hydrogen with lactate as the sole carbon source by using mixed microflora as well as a single culture. Microflora were isolated from a methane fermentation system, and their hydrogen productivity, fermentation properties, and diversity were analyzed. Since previous studies used inoculum pretreatment to improve efficiency, we used both pretreated and non-pretreated samples. The hydrogen yield of the non-pretreated microflora sample was 0.43 mol/mol lactate, which is approximately 49 times the values reported previously. Megasphaera elsdenii was found to be the main lactate utilizing-hydrogen producing bacteria (LU-HPB) in this sample, but it is not heat-shock tolerant. Thus, heat-shock pretreatment reduces microbial diversity, including lactic acid bacteria (LAB) and LU-HPB, in the inoculum. This is another ‘blind spot’ of hydrogen fermentation from lactate. The hydrogen yield of M. elsdenii was approximately 0.4 mol/mol lactate. Considering the balance of metabolites in the reaction, even if the substrate was completely consumed for lactic acid fermentation, 0.8 mol hydrogen per mol of glucose may be recovered via homo-type lactic acid fermentation. Thus, LU-HPB do not require inoculum and/or substrate pretreatment and may improve the utilization of recalcitrant substrates such as xylose by cooperating with LAB. To our knowledge, this is the first study to identify and characterise a microbial hydrogen fermenter that can use lactate as the sole carbon source.