Microbial Colony Counts Research Articles

NANO-ENGINEERED IRRIGATING SOLUTIONS AND LASERS – AN ANTIBACTERIAL STUDY AGAINST ENTEROCOCCUS FAECALIS

BACKGROUND:
 Enterococcus faecalis (E. faecalis) is the most commonly detected micro-organism in asymptomatic and persistent endodontic infections. Thorough disinfection of the root canal is more important than proper shaping for a successful endodontic treatment. This study is an attempt to implement nanoparticles which have proven anti-bacterial efficacy as irrigating solutions against E. faecalis.
 AIM:
 To compare and evaluate the anti-bacterial efficacy of 5% sodium hypochlorite (NaOCl), 0.2% chitosan nanoparticles solution (ChNP) and 0.01% silver nanoparticles solution (AgNP) against E.faecalis with and without diode laser activation.
 MATERIALS AND METHODS:
 70 single rooted mandibular premolars were included in this study. Access opening, working length determination and biomechanical preparation were standardized. Samples were embedded in putty material inside an eppendorf tube to simulate periodontal ligament and autoclaved followed by inoculation of E.faecalis (MTCC 439) and incubated at 37℃ for 7 days. The samples were divided into 7 groups (10 samples in each group). Group 1- No treatment (Negative control), group 2 - 5% NaOCl without activation (Positive control), group 3 - 5% NaOCl with diode laser activation, group 4- 0.01% AgNP without activation, group 5- 0.01% AgNP with diode laser activation, group 6- 0.2% ChNP without activation and group 7- 0.2% ChNP with diode laser activation. A final rinse of the respective irrigants and activation were performed, followed by counting the colony forming units. Statistical analysis used were one-way analysis of variance (ANOVA) followed by Tukey’s post-hoc tests. Results showed that diode laser in combination with 5% NaOCl and 0.2% ChNP had significant effects in the reduction of microbial colony counts of E. faecalis in comparison to other experimental groups.
 Keywords: Nanoparticles, Irrigation, LASER, Enterococcus faecalis

Characteristics of Microbial Colony Counts on Agar Plates for Food and Microbial Culture Samples

Microbial colony counts of concern of food products are one of the most important items in microbiological examinations. The distributions of colony counts per agar plate of food samples are considered to be reflected with microbial cell distributions in food homogenates. However, (i) the probabilistic distributions of the colony counts per agar plate at the dilution of counting and (ii) the relationship between the colony counts per plate and the number of agar plates for food samples have not been intensively studied so far. In this study, therefore, these two points were studied with raw food samples of raw minced beef and chicken and raw milk and microbial culture samples of Escherichia coli, Staphylococcus aureus, and Saccharomyces cerevisiae. Among four major probabilistic distributions, it was found that aerobic plate counts per plate of the foods were well described with negative binomial, Poisson, and normal distributions and that the colony counts per plate of microbial cultures were described well with binomial, Poisson, and normal distributions. The effect of the number of agar plates on the estimation of the mean of colony counts per plate of a sample was then studied with the data randomly resampled from the experimental data. The resampled data showed that with more number of plates the mean of counts fluctuated less and the coefficients of variation of colony counts per plate decreased further, which were coincident to the estimated by the central limit theory. Our study would provide useful information on the characteristics of colony counts per plate of food samples which are routinely examined.

Effect of cleaning guidelines implementation on microbial colony count of laparoscopic instruments: A study in a public hospital in Iran.

Some countries have implemented reuse of laparoscopic instruments for cost-effective purposes. An accurate cleaning as the first step of reprocessing would lead to the effective sterilization. The purpose was to evaluate the effect of cleaning guidelines implementation on microbial load of laparoscopic instruments which were used in laparoscopic cholecystectomy surgery. This experimental study was done in an educational hospital, in 2017 and included a total of 128 laparoscopic instruments randomly selected from cholecystectomy surgeries and divided into two cleaning groups. The instruments were checked out in terms of number (colony-forming units [CFU]/mL) and type of microorganisms in two groups of routine cleaning and according to guideline cleaning. This guideline was indigenous and taken from successful instruction in this context that was presented by the Association for the Advancement of Medical Instrumentation (AAMI). The appropriate statistical analysis was conducted by SPSS version 19. The average microbial load was 2.4 × 106 CFU/100 mL after clinical use. It was reduced to 7.2 × 105 CFU/100 mL in the control group and 3.4 × 104 CFU/100 mL in the intervention group, after the cleaning process. The most common microorganisms that were isolated immediately after clinical use were Escherichia coli 81.2%, Pseudomonas 68.8%, Klebsiella 57.8%, and spp., and so on. The AAMI cleaning method is recommended to be utilized by operating room nurses for laparoscopic instruments.

Time-Dependent Changes in the Intestinal Microbiome of Gilts Exposed to Low Zearalenone Doses.

Zearalenone is a frequent contaminant of cereals and their by-products in regions with a temperate climate. This toxic molecule is produced naturally by Fusarium fungi in crops. The aim of this study was to determine the influence of low zearalenone doses (LOAEL, NOAEL and MABEL) on the intestinal microbiome of gilts on different days of exposure (days 7, 21 and 42). Intestinal contents were sampled from the duodenal cap, the third part of the duodenum, jejunum, caecum and the descending colon. The experiment was performed on 60 clinically healthy gilts with average BW of 14.5 ± 2 kg, divided into three experimental groups and a control group. Group ZEN5 animals were orally administered ZEN at 5 μg /kg BW, group ZEN10—10 μg ZEN/kg BW and group ZEN15—15 µg ZEN/kg BW. Five gilts from every group were euthanized on analytical dates 1, 2 and 3. Differences in the log values of microbial counts, mainly Escherichia coli and Enterococcus faecalis, were observed between the proximal and distal segments of the intestinal tract on different analytical dates as well as in the entire intestinal tract. Zearalenone affected the colony counts of intestinal microbiota rather than microbiome diversity, and its effect was greatest in groups ZEN10 and ZEN15. Microbial colony counts were similar in groups ZEN5 and C. In the analysed mycobiome, ZEN exerted a stimulatory effect on the log values of yeast and mould counts in all intestinal segments, in particular in the colon, and the greatest increase was noted on the first analytical date.

Biodegradation of modified Poly(lactic acid) based biocomposite films under thermophilic composting conditions

This study evaluates the aerobic biodegradation of modified Poly(lactic acid) (PLA) based biocomposites under composting condition. Samples of neat PLA (NPLA), PLA/chitosan 5% (modified) (PLA/Chitosan), PLA/CNCSO4 (̴1%) (PLA/CNC) and PLA/Gum Arabic 5% (modified) (PLA/Gum) were used for evaluation of biodegradation under simulated composting condition without adding any inoculum to the compost and utilizing the thermophilic microflora already present in the compost. Various analytical techniques like molecular weight analysis, differential scanning calorimetry (DSC), contact angle analysis and microbial colony count were used for analysis of biodegradation. Colony formation was analyzed and was found to be 5.12 × 106 cfu/ml in PLA/Chitosan sample. Contact angle measurement was employed for understanding biodegradation over a period of 70 days for the biocomposites. Biodegradation study was also confirmed through decrease in transparency and major peak shift in infra-red (IR) spectroscopy. DSC studies showed increase in crystallinity for all the degraded test samples, which confirms biodegradation. The results confirmed modified PLA films as biodegradable and also confirmed suitability of the test system for studying biopolymer biodegradation.

Metabolomics and bacterial diversity of packaged yellowfin tuna (Thunnus albacares) and salmon (Salmo salar) show fish species-specific spoilage development during chilled storage

Microbial (colony counts, 16S rRNA gene amplification), chemical (pH, 1H NMR spectroscopy) and sensory changes in raw Atlantic Salmon (Salmo salar) and tuna (Thunnus albacares) fillets stored under vacuum at 3 °C were evaluated over a period of 12 days. Both species of fish are globally important and among the ten most consumed fishes in the world. Although the sensory analyses showed a decrease in the quality of both fish species, only the salmon fillets were considered spoiled at the end of the storage period. In salmon, trimethylamine was the main spoilage product and bacterial colony counts reached an average of 7.3 log10 cfu/g. The concentration of glucose decreased and the concentration of organic acids increased during storage revealing glucose fermentation. Photobacterium was the dominating genus in the salmon studied. In the tuna studied, the bacterial colony counts reached only an average of 4.6 log10 cfu/g. The dominating bacteria in tuna were Pseudomonas spp. Glucose levels did not decrease, suggesting that amino acids and lactate most likely acted as carbon sources for bacteria in tuna. In conclusion, the study revealed that salmon was clearly a more perishable fish than tuna.

Pentoxifylline Alone or in Combination with Gentamicin or Vancomycin Inhibits Live Microbe-Induced Proinflammatory Cytokine Production in Human Cord Blood and Cord Blood Monocytes In Vitro.

Neonatal sepsis and its accompanying inflammatory response contribute to substantial morbidity and mortality. Pentoxifylline (PTX), a phosphodiesterase inhibitor which suppresses transcription and production of proinflammatory cytokines, is a candidate adjunctive therapy for newborn sepsis. We hypothesized that PTX decreases live microbe-induced inflammatory cytokine production in newborn blood. Cord blood was stimulated with live microorganisms commonly encountered in newborn sepsis (Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, or Candida albicans) and simultaneously treated with antimicrobial agents (gentamicin, vancomycin, or amphotericin B) and/or clinically relevant concentrations of PTX. Microbial colony counts were enumerated by plating, supernatant cytokines were measured by multiplex assay, intracellular cytokines and signaling molecules were measured by flow cytometry, and mRNA levels were measured by quantitative reverse transcription-PCR. PTX inhibited concentration-dependent E. coli-, S. aureus-, S. epidermidis-, and C. albicans-induced tumor necrosis factor (TNF) and E. coli-induced interleukin-1β (IL-1β) production in whole blood, with greater suppression of proinflammatory cytokines in combination with antimicrobial agents. Likewise, PTX suppressed E. coli-induced monocytic TNF and IL-1β, whereby combined PTX and gentamicin led to significantly greater reduction of TNF and IL-1β. The anti-inflammatory effect of PTX on microbe-induced proinflammatory cytokine production was accompanied by inhibition of TNF mRNA expression and was achieved without suppressing the production of the anti-inflammatory IL-10. Of note, microbial colony counts in newborn blood were not increased by PTX. Our findings demonstrated that PTX inhibited microbe-induced proinflammatory cytokine production, especially when combined with antimicrobial agents, without enhancing microbial proliferation in human cord blood in vitro, thus supporting its utility as candidate adjunctive agent for newborn sepsis.

PENGARUH PENAMBAHAN LENGKUAS MERAH (Alppinia purpurata) TERHADAP KUALITAS DENDENG SAYAT IKAN BANDENG (Chanos chanos) SELAMA PENYIMPANAN

This study aimed to determine the effect of adding red galangal (Alppinia purpurata) to chemical, microbiological, and organoleptic qualities during storage.The type of this research is a quantitative research with experimental approaches and designed using completely randomized factorial design consist of two factors, namely factor A was the addition of galangal (control, 3%, 5%, and 7%) and factor B was the long of storage (0 day, 10 day, 20 day, 30 day) at room temperature. The number of treatmented was tested that as much as 16 treatments combinations. Each treatment combination was repetition at 3 times to obtain 48 units experiment The The parameters observed in this research were water content, fat content, microbial colony count (ALT), sensory test of aroma and appearance of hedonic, texture, and taste of jerky the fish milkfish. Data were analyzed by variance analysis techniques (ANOVA) and continued by duncan test. The best treatment was jerky of milkfish fish with the addition of galangal 7% during storage that was the highest addition of galangal treatment. As long as the storage of test parameters decreases with time of storage. The treatment of the addition of galangal 7% was the best of product because it could still maintain the physical properties of the appearance, texture, aroma and taste of jerky the fish milkfish until the storage of the 10 day

Factors influencing microbial colonies in the air of operating rooms

BackgroundThe operating room (OR) of the hospital is a special unit that requires a relatively clean environment. The microbial concentration of an indoor OR extrinsically influences surgical site infection rates. The aim of this study was to use active sampling methods to assess microbial colony counts in working ORs and to determine the factors affecting air contamination in a tertiary referral medical center.MethodsThis study was conducted in 28 operating rooms located in a 3000-bed medical center in northern Taiwan. The microbiologic air counts were measured using an impactor air sampler from May to August 2015. Information about the procedure-related operative characteristics and surgical environment (environmental- and personnel-related factors) characteristics was collected.ResultsA total of 250 air samples were collected during surgical procedures. The overall mean number of bacterial colonies in the ORs was 78 ± 47 cfu/m3. The mean number of colonies was the highest for transplant surgery (123 ± 60 cfu/m3), followed by pediatric surgery (115 ± 30.3 cfu/m3). A total of 25 samples (10%) contained pathogens; Coagulase-negative staphylococcus (n = 12, 4.8%) was the most common pathogen. After controlling for potentially confounding factors by a multiple regression analysis, the surgical stage had the significantly highest correlation with bacterial counts (r = 0.346, p < 0.001). Otherwise, independent factors influencing bacterial counts were the type of surgery (29.85 cfu/m3, 95% CI 1.28–58.42, p = 0.041), site of procedure (20.19 cfu/m3, 95% CI 8.24–32.14, p = 0.001), number of indoor staff (4.93 cfu/m3, 95% CI 1.47–8.38, p = 0.005), surgical staging (36.5 cfu/m3, 95% CI 24.76–48.25, p < 0.001), and indoor air temperature (9.4 cfu/m3, 95% CI 1.61–17.18, p = 0.018).ConclusionsUnder the well-controlled ventilation system, the mean microbial colony counts obtained by active sampling in different working ORs were low. The number of personnel and their activities critically influence the microbe concentration in the air of the OR. We suggest that ORs doing complex surgeries with more surgical personnel present should increase the frequency of air exchanges. A well-controlled ventilation system and infection control procedures related to environmental and surgical procedures are of paramount importance for reducing microbial colonies in the air.

A Novel Herbal Formulation versus Chlorhexidine Mouthwash in Efficacy against Oral Microflora.

Aims and Objectives:The aim of the study was to compare and to analyze the antimicrobial efficacy of 0.12% chlorhexidine and new formulated herbal mouthwash after using for 14 days. The objective was to signify whether the noval herbal combination could be a better alternative mouthwash to Chlorhexidine (CHX).Materials and Methods:This is a double-blinded, random controlled research study conducted in the Department of Oral Pathology and Microbiology. A total of 200 dental students were selected randomly, comprising of two groups, 100 in each, aged between 18 and 22 years with gingival index of score II. The first group was advised to oral rinse with 0.12% chlorhexidine mouthwash and the second group with new formulated herbal mouthwash for 14 days. Saliva samples were collected on the day 0 (baseline), followed by day 7 and 14 and microbial colony count was performed. The data obtained was statistically analyzed using SPSS version 16. Student's t-test was applied for comparison of the mean microbial count between the two groups. Repeated measures analysis of variance followed by Tukey's post hoc test was applied to assess the changes from day 0 to day 7 to day 14. The statistical significance level was set at P < 0.05.Results:Microbial colonies were reduced better in chlorhexidine group on the day 7 whereas, on day 14, greater reduction was observed in the herbal group in both gender groups with high statistical significance (P < 0.001).Conclusions:Herbal mouthwash formulation performed effectively well on long-term usage, could be used as an alternative mouthwash to overcome the disadvantages of chlorhexidine.

Quantitative estimation of pollution in groundwater and surface water in Benin City and environs

Microbiological and physico-chemical analyses of groundwater and surface water samples collected from different parts of Benin City were carried out to investigate their pollution load. Microbiological analyses were carried out using pour plate method and most probable number (MPN) technique while physico-chemical properties were investigated using standard analytical methods. Microbial colony counts were most prominent in Nutrient Agar medium with values ranging from 7 x 10 3 cfu/ml to 59 x 10 3 cfu/ml, while counts in MacConkey and PDA ranged from 5 x 10 3 cfu/ml to 40 x 10 3 cfu/ml and 2 x 10 3 cfu/ml to 8 x 10 3 cfu/ml respectively. Bacterial and fungal isolates were Bacillus spp. Klebsiella spp. Enterobacter spp. Micrococcus spp. Flavobacterium spp, Serratia marcescens , Aspergillus spp and Candida spp. The MPN result ranged from 1.0 x10MPN/100ml to 30.0 x10 MPN/100ml. There was no record of fecal coliform count. Physico-chemical parameters were compared with regulatory standards from Federal Ministry of Environment for drinking water and they all fell within permissible limits except (Dissolved oxygen 28-30.55 mgl -1 ), total suspended solids (16-44.5mg/l), and Biological oxygen demand (8.3-76.5). This presents socio-economic and public health concerns. Constant monitoring is recommended to provide information on water quality and health guide. Keywords: Microbial load, Physico-chemical properties, Water sources, Benin City

English

The impact of 9 months cultivation of transgenic Bacillus thuringiensis (Bt) cotton on selected culturable bacterial and fungal populations in rhizosphere soil was investigated. The transgenic Bt cotton line (06Z604M), isoline (99M03) and a non-Bt cotton line (HART 89M) were planted in confined field site in Samuru-Thika where non-Bt cotton had been continuously cultivated for the past 2 years. Rhizosphere soil samples were collected at planting, maturity, flower and boll, and boll-opening stages and harvesting stages of cotton. Numbers of culturable soil microbial groups (bacteria, actinomycetes and fungi) involved in decomposition and nutrients recycling were measured at CFU and population levels. The proteins did not show effects on bacterial, actinomycetes and fungal counts and populations possibly as a result of adsorption of the proteins on soil particles, which could have rendered the proteins inaccessible for microbial utilization. Culturable microbial population and colony counts arranged in decreasing order were 06Z604D>99M03>HART89M, similar to the amounts of MBC and clay in the soils. Moreover, bacteria and fungi counts were higher at 110 DAS in 06Z604D than in 99M03 and HART89M plot soils. Our observations suggest that insecticidal proteins (Cry1Ac and Cry2Ab2) produced by Bollgard II Bt cotton could persist in tropical soils as a result of adsorption on soil clays but that there were no observable effect on the studied culturable microbial groups.The data presented here showed no consistent statistically significant differences (p 0.001) with soil respiration and microbial biomass, which exhibited uneven trend with the treatments. Generally Soil from 06Z604D showed the slight higher microbial populations and CFU count, whilst HART 89M showed slight lower microbial count. This depicts the fact that slight variability in the treatments, quality and content of the root exudates might have a temporal or permanent shift in micro biota populations of a variety of crop studied.This study therefore suggests that a single-year cultivation of transgenic Bt cotton may not affect the functional bacterial and fungi populations in rhizosphere soil. Key words: Bacillus thuringiensis, bacteria, population, colony forming units, fungi, Bt cotton.

Breaking the Chain of Infection: Dental Unit Water Quality Control.

The air-water syringes, ultrasonic scalers, high speed air turbine handpieces are connected to dental units by a network of small-bore plastic tubes through which water and air travel to activate or cool the instruments and it had been shown that this system is extensively contaminated with microbial biofilms and pose a potential risk of infection for patients as well as dental professionals. To evaluate and compare the efficacy of various disinfectants in reducing the microbial colony count in water derived from Dental Unit Waterlines. Five random dental units were selected and samples were collected before and after intervention with 5 disinfectants (0.02% H2O2 continuously, 0.02% H2O2 continuously with shock treatment with 0.25% H2O2 weekly, 0.12% Chlorohexidine and 12% Ethanol overnight, 1:50 Original Listerine overnight, 2% Sodium Perborate and 2% EDTA 5 minutes in morning) using different disinfection methods for 4 weeks. Samples were cultured on Reasoner's 2A (R2A) agar for microbial counting. Results were recorded as Colony forming units/ml (cfu/ml) and were evaluated statistically. Results showed that all the dental unit waterlines were heavily contaminated with microbes before any intervention. After 1 day of disinfection regime the counts reduced significantly and showed progressive reduction in consecutive weeks. Goals set by ADA & CDC were ultimately achieved at the end of 4 weeks. All the disinfectants were equally effective in reducing the microbial colony count of DUWLs, irrespective of their concentration and method of disinfection.

Evaluación de los efectos de la suplementación de aceite de pescado y té verde en la microflora de la molleja, íleon y ciego en pollos de engorde

Con el fin de evaluar los efectos de la sustitución del aceite de soja por aceite de pescado (AP) y del té verde (Camellia sinensis L.; GT) en polvo, a bajos niveles, sobre la microflora del tracto digestivo, 270 pollitos machos de la cepa Ross 308 y un dia de edad fueron asignados aleatoriamente en 9 grupos con 3 repeticiones y 10 aves cada uno. Las dietas de los períodos de inicio, crecimiento, y acabado incluían la sustitución de una parte el aceite de soja por 0, 1,5 o 2,0 % de AP y 0; 1,0 o 1,5 % de polvo de GT. En el día 42, se recogieron los contenidos de la molleja, íleon y ciego de un ave sacrificada en cada réplica, para cultivos microbianos y recuento de colonias. El número medio (mínimos cuadrados medios log10 UFC/g±SEM) de bacterias aeróbicas (7,396 ± 0,931), bacterias productoras de ácido láctico (8,165±0,900), coliformes (7,033±0,892) y bactérias intestinales lactosa negativas (6,559±0,823), provenientes del contenido cecal de las aves alimentadas con 2 % AP fueron similares a todos los demás grupos. Tampoco se observaron diferencias significativas entre los grupos para el contenido de la molleja y del íleon. Estos resultados sugieren que la suplementación en la dieta del AP hasta 2,0 % más GT hasta el 1,5 % no afectan negativamente o incluso puede preservar el equilibrio de la microflora de la molleja, el íleon y el ciego de pollos aparentemente sanos. El aceite de soja se puede sustituir parcialmente por AP hasta el nivel 2,0 % sin efectos adversos aparentes sobre la microflora intestinal.

Comparison of Anti-Bacterial and Anti-Inflammatory Properties of Neem, Curcumin and Aloe Vera in Conjunction with Chlorhexidine as an Intracanal Medicament – an In-Vivo Study.

Abstract Aim &amp; Objective: The main aim of this study was to evaluate the potential of Neem, Curcumin and Aloe vera as an effective intracanal medicament in root canal therapy of infected teeth and to determine the antimicrobial and anti-inflammatory properties of these three herbal substances used in the study. Material and Method: In this study, thirty three patients(33) within the age group of 25-40 years with two single rooted anterior teeth, presenting with periapical radiolucency requiring endodontic therapy were selected. These 33 patients were divided into two groups, in which one was the test and another was control in one single patient. The control samples were taken from all the 33 patients i.e (33 samples) in which chlorhexidine is used as intracanal medicament, whereas the test groups were divided into another three respective groups with 11 samples in each group on the basis of three herbal intracanal medicaments used in this study. The antimicrobial and anti-inflammatory property was assessed in our study using the microbial colony count method and the Visual analogue pain scale method respectively. Results: Test Group A(Neem) showed the highest antibacterial activity with maximum reduction in microbial colony count scores. and the test Group B(Curcumin) showed the highest anti-inflammatory activity with maximum reduction in the VAS pain score. On comparing test groups with control group and antimicrobial property was analyzed. The results were statistically non-significant when Group A(Neem) was compared with Control group(Chlorhexidine) and statistically significant when Group B(Curcumin) and Group C(Aloe vera) was compared with Chlorhexidine.

ACTION OF NEWER DISINFECTANTS ON MULTIDRUG RESISTANT BACTERIA

BACKGROUND: Current procedures for infection control in hospital environments have not been successful in curbing the rise in infections by multi-drug-resistant (MDR) pathogens. Emergence of resistance to chemical disinfectants is increasing steadily and has been reported worldwide. So prevention of multidrug-resistant health care associated infections (HAI) has become a priority issue and great challenge to clinicians. This requires appropriate sterilization and disinfection procedures and strict adherence to protocol in infection control policy. There is a need to evaluate the efficacy of newer disinfectants which have come into the market for better control of HAI. AIMS AND OBJECTIVES: The aim of this study was to evaluate and compare disinfection efficacy of three newer disinfectants– Novacide (didecyldimethylammonium chloride and polyhexamethylene biguanide), Silvicide a strong oxidizing agent (hydrogen peroxide and silver nitrate) and Virkon, a powerful oxidizing agent (a stabilized blend of peroxygen compounds and potassium salts), pitting them against two time-honored conventional disinfectants phenol and lysol and testing them against common MDR clinical isolates, reference strains and spores. MATERIALS AND METHODS: All the disinfectants at different dilutions were tested for bactericidal efficacy by liquid suspension time-kill tests. A heavy initial microbial load was simulated by preparing bacterial inoculum. Numbers of viable cells were counted and reduction in microbial colony counts before and after disinfectant exposure was expressed as log reduction. RESULTS: Among the disinfectants, Novacide was most effective. All clinical MDR bacterial isolates and reference strains were killed within 30 seconds of exposure at 0.156% solution, whereas spores got killed after 30 minutes of exposure at 2.5% solution which is the recommended concentration. For Silvicide all vegetative bacteria were killed at 5% solution after 20 minutes contact time and at 20% solution after 10 minutes contact time where recommended concentration is 20%. Spores also were killed at 20% solution after 1 hour contact time. Virkon was very effective for vegetative bacteria at 1% solution (which is the recommended concentration), killing within 30 seconds, but for exerting sporicidal action took 2 hours contact time. The conventional disinfectant phenol has currently restricted use because of its corrosive nature and high toxicity but still is considered as standard disinfectant for microbicidal efficacy testing methods. Lysol, the most widely used hospital disinfectant was found to be least effective among the five disinfectants. Both phenol and Lysol exerted poor sporicidal effect. CONCLUSION: Novacide is the most effective disinfectant in our study. Also Silvicide and Virkon being sporicidal agent can be considered as high level disinfectant, but Virkon required much greater time exposure inappropriate for routine hospital uses including instrument disinfection, floor cleaning and waste disposal.

Ascophyllum extract application can promote plant growth and root yield in carrot associated with increased root-zone soil microbial activity

Alam, M. Z., Braun, G., Norrie, J. and Hodges, D. M. 2014. Ascophyllum extract application can promote plant growth and root yield in carrot associated with increased root-zone soil microbial activity. Can. J. Plant Sci. 94: 337–348. Root growth and soil microbial activity were examined in two cultivars of carrot following treatment with Ascophyllum nodosum marine-plant extract. Field experiments were established in grower-managed fields of Maverick and Pronto carrots during 2010 and 2011. Soluble Ascophyllum extract powder (SAEP) was applied weekly, bi-weekly or tri-weekly at rates of 0 (control), 0.25, 0.50, 0.75 or 1.0 g L−1 over 11 to 13 wk. Results indicate that SAEP treatment increased root yields of Maverick and Pronto by about 20 and 15%, respectively, reduced proportion of smaller roots and improved harvest index (HI). Maximum yield was found at or above 0.50 g L−1 SAEP for Maverick and at 0.75 g L−1 for Pronto. Soil microbial colony counts, respiration and metabolic activity increased following SAEP applications, but varied with SAEP rate and application frequency. Using the Biolog microbial analysis system, maximum average well colour development (AWCD), substrate diversity (H), substrate evenness (E), and substrate richness (S) responses to extract treatment generally showed successive increases at 0.50, 0.75 and 1 g L−1 SAEP at tri-weekly application frequencies. With more frequent applications, rates below 1 g L−1 led to greater microbial growth, respiration and functional activities. Principal component analysis (PCA) showed a strong relationship between carrot growth, soil microbial populations and activity parameters. These results suggest that seaweed extract application can result in an increase in soil microbial activity associated with increased yield in carrots.

Comparative evaluation of the efficacy of two controlled release devices: Chlorhexidine chips and indigenous curcumin based collagen as local drug delivery systems.

Aim:To comparatively evaluate the therapeutic efficacy of chlorhexidine (CHX) chips (Periocol-CG) and indigenous curcumin (CU) based collagen as adjuncts to scaling and root planning in the nonsurgical management of chronic periodontitis.Materials and Methods:A total of 120 sites from 60 patients presenting with chronic periodontitis (age group 25-55 years) of both sexes, with pocket depth of ≥5 mm with radiographic evidence of bilateral bone loss were earmarked for the study. A split mouth design was employed, and all the clinical parameters-plaque index, gingival index, probing pocket depth (PPD) and clinical attachment levels (CAL) were recorded at baseline, 1 month, 3 months, and 6 months. However, the microbiological parameters, i.e., N-benzoyl-DL-arginine-β-naphthylamide (BANA) test and microbial colony count were recorded at baseline, 3 months and 6 months postoperatively.Results:Significant reduction in plaque and gingival index scores were observed in both groups at the end of the study period, i.e., 6 months. The microbiological parameters (BANA test, microbial colony count), PPD and CAL levels also showed significant improvement in both groups. However, at the end of the study period CHX group showed greater improvement in all of these parameters compared to CU collagen group.Conclusion:Future directions of this study should include targeting the beneficial effects of these local drug delivery systems at varied concentrations so that they could be utilized to achieve the maximum beneficial therapeutic effects in the nonsurgical treatment of periodontal disease.

Voided Midstream Urine Culture and Acute Cystitis in Premenopausal Women

BackgroundThe cause of acute uncomplicated cystitis is determined on the basis of cultures of voided midstream urine, but few data guide the interpretation of such results, especially when gram-positive bacteria grow.MethodsWomen from 18 to 49 years of age with symptoms of cystitis provided specimens of midstream urine, after which we collected urine by means of a urethral catheter for culture (catheter urine). We compared microbial species and colony counts in the paired specimens. The primary outcome was a comparison of positive predictive values and negative predictive values of organisms grown in midstream urine, with the presence or absence of the organism in catheter urine used as the reference.ResultsThe analysis of 236 episodes of cystitis in 226 women yielded 202 paired specimens of midstream urine and catheter urine that could be evaluated. Cultures were positive for uropathogens in 142 catheter specimens (70%), 4 of which had more than one uropathogen, and in 157 midstream specimens (78%). The presence of Escherichia coli in midstream urine was highly predictive of bladder bacteriuria even at very low counts, with a positive predictive value of 102 colony-forming units (CFU) per milliliter of 93% (Spearman's r=0.944). In contrast, in midstream urine, enterococci (in 10% of cultures) and group B streptococci (in 12% of cultures) were not predictive of bladder bacteriuria at any colony count (Spearman's r=0.322 for enterococci and 0.272 for group B streptococci). Among 41 episodes in which enterococcus, group B streptococci, or both were found in midstream urine, E. coli grew from catheter urine cultures in 61%.ConclusionsCultures of voided midstream urine in healthy premenopausal women with acute uncomplicated cystitis accurately showed evidence of bladder E. coli but not of enterococci or group B streptococci, which are often isolated with E. coli but appear to rarely cause cystitis by themselves. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases.)

Comparative evaluation of microbial colony counts on sutures with and without use of periodontal pack: a split mouth, randomized controlled study

Background & Aim: Periodontal dressings are commonly used following surgical procedures due to varied reasons. Though several studies have been done on periodontal dressings, not many have stressed upon the microbial load due to plaque retention. This study was undertaken to evaluate the use of the periodontal dressing following routine periodontal flap surgery to no dressing, in terms of added microbial load due to increased plaque retention. Methods: 20 patients from the Dept. of Periodontics, K. M. Shah Dental College and Hospital, undergoing flap surgical procedures in bilaterally identical areas were selected. Following the flap surgical procedure, half the area (20 sites) was given a periodontal dressing (test group) and the other half (20 sites) was left undressed (control group). Sutures were removed at day 7 from both the sides and plaque samples from the sutures were taken for culture on nutrient agar and blood agar and were assessed for colony forming units (CFU). Results: The cultures from the test group showed higher CFU on both blood and nutrient agar (p Conclusion: Periodontal dressings facilitate debris and microbial growth and add to the microbial load of the surgically dressed areas.