Lower Colony Counts Research Articles

UVC (254 nm) and Far UVC (222 nm) Irradiation Affects In Vitro Growth of Colletotrichum sp. Isolates and Their Infection of Detached Strawberry Leaves

Conventional ultraviolet C at 254 nm (UVC) and Far UVC at 222 nm (Far UVC) were evaluated as alternatives to fungicides for disease control. Conidia of 13 isolates of strawberry anthracnose pathogens (five Colletotrichum species in two complexes: C. acutatum and C. gloeosporioides) were uniformly dispersed onto agar and irradiated with UVC and Far UVC doses ranging from 52 to 1,248 J·m−2. After 48 h of incubation, a UVC dose of 1,248 J·m−2 and Far UVC doses from 234 to 935 J·m−2 reduced Colletotrichum colony counts to <10 colonies/Petri dish. Cultures exposed to UVC light followed by 4 h of darkness had lower colony counts than cultures incubated under continuous light. This dark incubation period was not required for Far UVC to obtain optimal lethality, indicating Far UVC irradiation can be applied during the day or night and achieve similar fungal lethality. Inoculation of detached leaves of three anthracnose-susceptible strawberry cultivars with conidial suspensions of Colletotrichum spp. revealed that UV irradiation can affect development of anthracnose symptoms. Leaves receiving UVC doses of 312 and 624 J·m−2 or a Far UVC dose of 467 J·m−2 reduced anthracnose infection with little or no plant injury. A UVC dose of 1,248 J·m−2 and Far UVC doses ≥ 467 J·m−2 inflicted varying degrees of plant injury. Disease control intended to reduce the number of fungicidal applications could be developed with moderate doses of UVC and Far UVC irradiation while slowing the evolution of pesticide-resistant strains. [Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 “No Rights Reserved” license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2024.

Bacteria Load Assessment from Hands of Students in a Tertiary University in South-South Nigeria

Clean hands are the single most important factor in preventing the spread of pathogens and reducing the incidence of infections. The good hand hygiene practices promote health safety and prevent infections. This study was carried out to assess the presence of bacteria from hands of Ambrose Alli University Students. Of all fifty (50) samples analyzed, at least one or two bacteria were isolated. The colony counts of students from each site were properly recorded with the highest found amongst dwellers of male hostels i.e 4.85 x 105cfu/ml, compared to dwellers at female hostels. However, there was considerable increase amongst students at Microbiology laboratory, which may be attributed to lack of good hand hygiene procedures not been adhered to. The considerable increase in the frequency of Escherichia coli and as well as Proteus sp is indicative of poor hygiene practices. The low colony counts recorded amongst students from school gate could be as a result of the student have taken their bath before coming to school. The frequency of occurrence of the isolates includes: Staphylococcus aureus 50 (100%), Escherichia coli 35 (70%), Klebsiella sp 15 (30%), Salmonella sp 21 (42%), Streptococcus sp 10 (20%), Bacillus sp 4 (8%), Pseudomonas sp 2 (4%) and Proteus sp 2 (4%). From the study, it was shown that there was considerable increase in poor hygienic practices amongst students of Ambrose Alli University, Ekpoma Edo State, Nigeria.

The First Known Documented Case of Ewingella Americana Urinary Tract Infection

We present a 73-year-old male with a history of end-stage renal disease (ESRD) on dialysis, type 2 diabetes mellitus, coronary artery disease status post stents, prostate carcinoma status post radiation, and prostatectomy, with recurrent bladder neck contracture requiring suprapubic catheter, left urethral stricture with nephrostomy tube placement, penile implant, and recurrent urinary tract infections, who presented to the emergency room complaining of constant bilateral groin pain for one day. Physical exam was significant for suprapubic tenderness and a chronic suprapubic catheter and left-sided nephrostomy tube. An initial examination of the patient's urine revealed turbid, yellow-colored fluid, positive for white blood cells, leukocyte esterase, and bacteria. A urine culture was obtained, which returned positive for E. americana, with>100,000colony-forming units (CFUs)as well as Enterococcus faecalis (E. faecalis) demonstrating low colony counts.The patient was treated with a seven-day course of meropenem 1 gm twice daily, whichimproved of his symptoms, and then completed a 10-day course of ertapenem 500 mg daily. The patient received a five-day course of vancomycin 1 gm on dialysis days for additional coverage of E. faecalis, despite low colony counts. This is the first documented case of a urinary tract infection caused by E. americana.The organism is primarily found in immunocompromised individuals, and a debate is still ongoing as to whether it is a true pathogen or exists primarily as an opportunistic infection.We suggest further inquiry and study of this resistant organism are paramount in establishing its role in both immunocompromised as well as immunocompetent individuals.E. americana is a multidrug-resistant organism, which to date has sparse documentation regarding its prevalence and potential for morbidity, especially in compromised individuals.In the era of increasing antibiotic resistance, we suggest that more research is needed to understand the pathogenicity of E. americana.

Performance of four bacterial cell counting apps for smartphones

Quantifying bacterial colony forming units is important in microbiological diagnostics. Recent progress in imaging technology allows automation of this tedious and error-prone task. We compared the accuracy of four smartphone colony counter applications conducting standardized measurements, using a self-built apparatus. One app showed high accuracy at lower colony counts.

The effect of washing with water and detergent on increasing the shelf life of pepper (Capsicum annum) on sale at Rimi and Tarauni markets of Kano State, Nigeria

Sample of pepper was collected from two selected vegetable markets and used to determine the most effective method of increasing shelf life of pepper. In the research two treatment methods used by marketers of vegetables washing with water and detergent were compared. The results showed that five fungal colonies were isolated from pepper samples obtained from the study aeas. The five fungal colonies isolated from the two markets have the following frequency of occurrence A. niger 17 ( 28.3 %) A. fumigatus 12 (23.3%), R. stolonifer 12 (20.0%), A. flavus 09(15.05%) and Mucor spp 08 (13.3%). Out of the total 60 fungal colonies isolated in the two markets, more colonies were counted from water wash pepper 37 ( 61.0%), while lower colony counts were recorded from detergent washed pepper in the two locations 23 ( 38.3%). It is clear therefore that, this investigation has established fewer fungal colonies counted from detergent washed samples in the two markets is that washing of pepper with detergent is more effective in increasing the shelf life of pepper by removing the surface contaminant micro-organisms.

English

This study evaluated the preservative ability of protein-like cell free supernatants produced by lactic acid bacteria (LAB) isolates from samples of Ictalurus punctatus (Cat fish) and slurry of fermented Zea mays (Ogi). The LAB strains were separately isolated from understudied samples using De Man, Rogosa and Sharpe (MRS) media at 37°C for 48 h. The isolated strains were characterized with Gram staining, oxidase and catalase tests, microscopy study, carbohydrate fermentation, acid production and NaCl tolerance. Thereafter, the protein concentrations of crude bacteriocin supernatants from the Gram positive, rod shaped, oxidase and catalase negative strains were studied. Also, the growth inhibition of Bacillus subtilis, Staphyloccocus aureus and Escherichia coli, heat stability, pH tolerance, effect of proteolytic enzyme and biopreservation efficiency of protein-like cell free supernatants (crude bacteriocins) were determined.  Biopreservative efficiency of the crude bacteriocin samples was also determined in orange (Citrus sinenses) and Titus fish (Scomber scombrus). The isolates from intestine of I. punctatus and fermented Z. mays fermented carbohydrate, and grew optimally at 3% NaCl, and 10 and 37°C, respectively. They inhibited the multiplication of E. coli at various extents, but more effective on different strains. The bacteriocins from slurry of fermented Z. mays on the other hand, were more potent in E. coli (22.7 ± 0.8 mm) than S. aureus (7.9 ± 0.1 mm). The biopreservative efficiency of crude bacteriocin from I. punctatus was greater than that of Z. mays. The LAB obtained from the selected samples produced protein-like substances in form of bacteriocins with potent antibacterial and biopreservative proficiencies through the growth inhibition of tested pathogens and low colony counts on tested food samples, respectively. Bacterial isolates obtained from samples of I. punctatus and Z. mays can be successfully used in the preservation of food and vegetables.   Key words: Ictalurus punctatus, Zea mays, bacteriocin, protein-like substances, biopreservative ability.

In vivo antibacterial and therapeutic properties of P. ostreatus against Staphylococcus aureus

Objectives: The use of natural products is embraced by a larger percentage of the world population. Most species of fungi including mushrooms produce useful secondary metabolites that stimulate the immune system against infection and diseases. Investigations were conducted to assay the therapeutic potentials of P. ostreatus against pathogenic staph infection.Methods: The methanol extract of P. ostreatus was prepared using the cold extraction method. Thirty Wistar albino rats weighing 82.0 g to 99.2 g were distributed into 6 groups of 5 and inoculated orally with actively growing Staphylococcus aureus suspension. P. ostreatus methanol extract LD > 5000 mg/kg 50 was used to determine the graded doses for the study. Graded doses of the extract 625 mg, 1250 mg, and 2500 mg were administered orally to the experimental animals for seven days.Results: The negative control and 625 mg had skin ulceration while 1250 mg to 2500 mg produced apparently healthy skin. Bacterial count after 7 days post-treatment was significantly high in the negative control and 625 mg dose (32.00 x 104 ± 6.10b; 43.40 x 104 ± 6.20b Cfu/ml) P< 0.05. Haematological and serum biochemical values were not significantly P < 0.05 affected. Pleurotus ostreatus administration at 1250 to 2500 mg produced a statistically low colony count that was comparable with 13.33 mg Ciprofloxacin and placebo.Conclusion: Pleurotus ostreatus at 1250 to 2500 mg was able to produce clinical recovery from S. aureus infection while 625 mg could not. The extract had no deleterious effect on the blood parameters, liver enzymes, and kidney biomarkers.

Effects of combined pulsed electric field and blanching pretreatment on the physiochemical properties of French fries

The aim of this work was to explore the effect of combining pulsed electric field (PEF) with blanching pretreatment on the physiochemical properties of French fries. The effects of PEF plus blanching pretreatment on the color parameters, texture, content and spatial distribution of moisture and oil, microstructure, colony count and acrylamide content of French fries were investigated. Results showed that the pretreated French fries were brighter (L value was 60.44) and golden yellow, with lower hardness (312.27 g), higher springiness (0.81) and higher chewiness (119.71). In addition, moisture and oil contents of the fries were reduced, with more uniform distributions. The cross-section microstructure of these French fries also showed near-complete gelatinization of starch particles, and the internal structure of fries was fluffy. Finally, French fries obtained by the combined pretreatment had an improved food safety profile, with a lower colony count (13 CFU/g) and acrylamide content (1533.75 ng/g). Industrial relevanceBlanching is a traditional thermal processing technology widely used in the field of fried potatoes. However, blanching has some disadvantages such as slow heat conduction, long processing time, substantial loss of soluble nutrients, and huge water wastage. PEF is an emerging technology in the 21st century that can maintain the original flavor, color, taste, and nutritional value of foods treated by it. The French fries obtained by combining PEF and blanching pretreatment were brighter and golden yellow, and were also softer, and more springy and chewy – an overall net improvement in aesthetic appeal and organoleptic profile. The above findings may provide useful information to guide effective strategies for the practical application of PEF combined with blanching in the preparation of fried potato foods.

Risk Score to Predict Time-to Sputum Smear and Culture Conversions in Patients Treated with Shorter MDR Tuberculosis Regime in Guinea: A Retrospective Cohort Study

Background: Sputum smear and culture examination were used as bacteriological marker to monitor multidrug-resistant tuberculosis (MDR-TB) treatment. We aimed to identify the strongest contributing factors that affect time-to sputum bacteriological conversion, and to develop a practical risk score. Methods: Patients treated with shorter MDR-TB treatment regime between June 07, 2016 and June 22, 2018 from three major drug-resistance TB centres in Guinea, who had a positive smear or culture at baseline, and who had rifampicin resistance were analysed. Sputum bacteriological conversion was defined as two consecutive negative smear or culture taken at least 30 days apart. Cox regression model was used to analyse time-to initial sputum conversion, and to identify influencing factors. A simple risk score was constructed using the regression coefficients from each final model. Time-dependent AUC was used to determine the optimal time points of bacteriological conversion. Results: 75% (173/232) of patients with a positive smear and culture at baseline were analyzed. A total, 90.2% (156/173) and 89% (154/173) of the patients had smear and culture conversions in a median of 59 days (inter-quartile range: 59–61) respectively. Lower colony count (<3 +) of initial culture (aHR=1.52, 1.09–2.14) and previously history of TB treatment (aHR=2.10, 1.26–3.51) were more likely to have culture conversion, while only the higher BMI (aHR=1.10, 1.03–1.18) was associated with rapid smear conversion. The predicted risk score from independent predictors showed good discrimination (0.855±0.023 and 0.883±0.02 respectively for smear and culture conversions). Time-to initial culture conversion provided a better discriminative capacity (AUC) to detect patients with higher chance to being treatment success during the first three months. Conclusion: The identified predictors can be considered to improve the management of MDR-TB patients. The optimal time points for culture conversion was three months in shorter regime.

1229. Two-Step Water Filtration and Control of Delftia acidovorans Hemodialysis Pseudo Outbreak

BackgroundReverse Osmosis (RO) technology improved the quality of water needed for hemodialysis (HD). Guidelines require low colony count (<100 cfu/ mL) in product water used for HD. It is not unusual to see occasional water cultures above the maximum allowable count. In this event the RO machine is pulled out of service, disinfected and returned to service only after repeat culture is negativeMethodsIn our institution, we had positive water culture from RO machine over a year duration that became persistently positive. Identification of the bacteria revealed Gram-negative environmental water cultures Delftia acidovorans. Despite all attempts to contain the pseudo outbreak (no clinical cases), all the RO were persistently positive. Renovation and replacement of all RO machines with Heat disinfection RO machines were performed.ResultsDelftia acidovorans grew from disinfection line, pump and product water were highly related using whole-genome sequencing. City water cultures were directly cultured repeatedly negative, and only after large volume filtration cultures grew Delftia. Despite the renovation, many machines were turning positive again. Two-step water filtration at the incoming water to the HD suite, was extremely effective in maintaining all water cultures negative for over 2 years after the pseudo outbreak.ConclusionDelftia Is a waterborne pathogen that is capable of forming a biofilm. 2-Step filtration (with 4 micron and less than a micron) is an expensive and effective way to improve the incoming water quality. Heat disinfection RO has a lower risk for development of a biofilm as compared with chemical disinfection RO. Disclosures All authors: No reported disclosures.

Assessment of Microbial Populations in the Manufacture of Vacuum-Packaged Ready-to-Eat Roast Beef and in a Related Production Plant

Some microbiological criteria were monitored for 6 months in vacuum-packaged roast beef (15 production batches), raw beef (10 batches), and other meat products (12 batches) produced in an Italian small to medium-size enterprise. Fifty-five environmental swab samples also were analyzed. The main bacterial groups were identified by cultural methods according to International Organization for Standardization standards. Listeria monocytogenes was enumerated with the most-probable-number protocol, and species identification was confirmed with a specific PCR assay. Immediately after vacuum packaging, all ready-to-eat (RTE) products had low mean aerobic colony counts (<102 to 2.4 × 102 CFU g-1), anaerobic colony counts (1.6 to 6.5 × 101 CFU g-1), Enterobacteriaceae counts (1.1 to 1.4 × 101 CFU g-1), and Escherichia coli counts (generally below the detection limit). Nevertheless, the prevalence of L. monocytogenes in these samples was 3.7%. In roast beef samples, the aerobic and anaerobic colony counts reached unacceptable levels (>106 CFU g-1) after 14 days of refrigerated storage. Because the prevalence of L. monocytogenes increased to 13.3% during storage, a substantial reduction in the shelf life of these products is recommended. Surfaces without direct contact with food (floors and drains) had the highest mean counts for aerobic colonies (8.0 × 103 to 9.5 × 105 CFU/cm2), anaerobic colonies (2.9 × 103 to 3.2 × 104 CFU/cm2), Enterobacteriaceae (1.5 × 101 to 8.4 × 101 CFU/cm2), and E. coli (6.0 to 7.7 CFU/cm2). The levels of L. monocytogenes on direct food contact surfaces were below the detection limit, but more than 25% of floor samples were contaminated. These results reveal the persistence of L. monocytogenes in food processing environments, although at very low levels, posing a high risk of postcooking recontamination for RTE products. To improve hygienic conditions and reduce cross-contamination, an increase in operator awareness and a reassessment of surface sanitization protocols are needed.

A comparative study on the effects of vancomycin, enrofloxacin, and trimethoprim/sulfamethoxazole on methicillin-resistant Staphylococcus aureus osteomyelitis in an animal model

Osteomyelitis is a serious medical issue that is refractory to treatments. Methicillin-resistant Staphylococcus aureus (MRSA) is a major problem in cases with osteomyelitis. These S. aureus have recently developed a resistance to vancomycin, which is a choice antibiotic for osteomyelitis. Therefore, finding alternative antibiotics is highly essential for treatment of methicillin-resistant S. aureus osteomyelitis. Twenty-four New Zealand adult white rabbits were experimentally infected by the injection of 106 colony-forming unit of Staphylococcus aureus in diaphysis of the tibia. Two weeks after injection, the animals were checked by microbiological and radiological tests for osteomyelitis. All infected rabbits were randomly divided into four groups of 6 including control, vancomycin, enrofloxacin, and trimethoprim/sulfamethoxazole, and every 12 h were administered with 30, 15, and 20 mg/kg, for treatment groups, respectively. Body weight, body temperature, and heterophil/lymphocyte ratio were assessed before and after inducing osteomyelitis. Then, the animals were treated in experimental groups for 2 weeks post infection. All of the experiment and control groups were humanely sacrificed. Subsequently, the bone specimens were separated for microbiological tests. The groups treated with vancomycin and enrofloxacin had significantly lower colony counts, and lower heterophil/lymphocyte ratio than control groups after treatment (P < 0.05). In this study, enrofloxacin had comparable efficacy to that of the vancomycin-treated group. However, trimethoprim/sulfamethoxazole did not show such efficacy. It can be inferred that enrofloxacin can be an effective antibiotic for the treatment of acute osteomyelitis caused by methicillin-resistant Staphylococcus aureus.

No. 276-Management of Group B Streptococcal Bacteriuria in Pregnancy.

To provide information regarding the management of group B streptococcal (GBS) bacteriuria to midwives, nurses, and physicians who are providing obstetrical care. The outcomes considered were neonatal GBS disease, preterm birth, pyelonephritis, chorioamnionitis, and recurrence of GBS colonization. Medline, PubMed, and the Cochrane database were searched for articles published in English to December 2010 on the topic of GBS bacteriuria in pregnancy. Bacteriuria is defined in this clinical practice guideline as the presence of bacteria in urine, regardless of the number of colony-forming units per mL (CFU/mL). Low colony counts refer to <100 000 CFU/mL, and high (significant) colony counts refer to ≥100 000 CFU/mL. Results were restricted to systematic reviews, randomized controlled trials, and relevant observational studies. Searches were updated on a regular basis and incorporated in the guideline to February 2011. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. Recommendations were quantified using the evaluation of evidence guidelines developed by the Canadian Task Force on Preventive Health Care (Table). The recommendations in this guideline are designed to help clinicians identify pregnancies in which it is appropriate to treat GBS bacteriuria to optimize maternal and perinatal outcomes, to reduce the occurrences of antibiotic anaphylaxis, and to prevent increases in antibiotic resistance to GBS and non-GBS pathogens. No cost-benefit analysis is provided.

Identification and Characterization of Candida on CHROMAgar™ in Pregnant Women of Multan, Pakistan

Introduction: Infections to vagina with fungi/yeast are ten times more common during pregnancy because of hormonal and biochemical fluctuations. Increased use of antibiotics and presence of high levels of reproductive hormones during pregnancy also stimulate yeast colonization with Candida species. These two contributes significantly to be an important risk factor in Vulvovaginal Candidiasis (VVC) and Urinary Tract Infections (UTI), a complication during pregnancies. Overall occurrence of UTI/vaginal yeast infections increases with progression of pregnancy and maximizes by third trimester worldwide. Study parameters: In the current study, pregnant women were look for presence of UTI by Candida species in different trimesters within the city of Multan. The total of 70 women with different gestational stages, attending gynecologists, aged 18-39 years were included in the investigation. A clean catch urine samples were cultured on CHROMAgar™ Candida, a selective medium, for the isolation and presumptive identification of yeast species. Of all samples, 25 women (36%) were positive for Candida yeast infection (symptomatically and asymptomatically). Colonies were identified as C. albicans (48%), C. krusei (16%), C. tropicalis (16%) along with some mixed infections with C. parapsilosis and C. krusei. Two of the mixed cultures (8%) were isolated with C. albicans and C. tropicalis, one (4%) with C. albicans and C. krusei, one (4%) with C. tropicalis and C. krusei. Results: The highest incidence, 36% (n=9/25), of candiduria was recorded in the age group of 30-35 years. The colony counts in urine were also studied in different gestational stages and age. Total of 23% isolations share high counts (>1000 CFU/mL). While other 33% have intermediate (<600 CFU/mL) and 30% isolates were with low colony counts (<150 CFU/mL). The species distribution in these positive specimens reveals increased percentages of nonalbicans species with increasing gestational stage. Conclusion: From these findings it is concluded that incidence of candiduria in pregnant women were higher in 2nd and 3rd trimester of pregnancy with an increase in mixed Candida infections in young women. It is recommended to educate the group so that less young individuals are affected.

Different Behavior and Response of Staphylococcus Epidermidis and Streptococcus Pneumoniae to a Ventriculoperitoneal Shunt: An in vitro Study

Background: Pneumococcal shunt infection is a rare event. There is no consensus on the therapeutic management of this kind of shunt infection according to literature reviews, and it seems to be different from infection with Staphylococcus epidermidis. We studied 2 shunted patients with pneumococcal meningitis, both of whom were treated with only antibiotics. The management of these cases seems to be different from that of shunt catheter infection due to these bacteria. We conducted a laboratory study to show the different behavior of pneumococcus compared to S. epidermidis regarding shunt catheter colonization. Materials and Methods:S. epidermidis and Streptococcus pneumoniae bacteria isolated from the cerebrospinal fluid of meningitis patients were incubated in sterile media. Forty-five segments of shunt catheter from silicone material were placed in 45 separate media of S. epidermidis and pneumococcus. Then each catheter was washed and cultured in blood chocolate agar growth medium in separate petri dishes via the roll plate method. The dishes were extracted from the incubator and the colony count was calculated after 72 h. Results: The colony count was obviously different between the 2 bacteria groups, with a higher count related to S. epidermidis dishes. The colony count of the pneumococcal petri dishes was 25-35,000 (mean 14,337) and for dishes with S. epidermidis it was 14,000-100,000 (mean 50,125) (p = 0.001). Conclusion: The adherence of pneumococcus to shunt catheters seems to be much less than that of S. epidermidis, which produced a very low colony count when incubated with the catheter in the medium culture. S. pneumoniae meningitis in shunted patients can be managed successfully with only antibiotics. This approach can prevent problems related to the several additional surgeries required for shunt removal, a new shunt insertion, and the management of high intracranial pressure.

Pasteurella aerogenes as an Asymptomatic Bacteriuria Agent

'Asymptomatic bacteriuria' (ASB) is isolation of a specified quantitative count of bacteria in an appropriately collected urine specimen obtained from a person without symptoms or signs referable to urinary infection. Catheterized specimens are less likely to be contaminated compared with voided specimens; therefore, positive cultures of catheterized specimens are more likely to reflect true bladder bacteriuria even with low colony counts. The common pathogens for ASB are Escherichia coli, Klebsiella and Streptococcus spp. Pasteurella spp. was not previously reported as an ASB agent. ASB is important for pregnant women, children, individuals with obstructive uropathy, chronic renal failure and neutropenia, before the urologic procedures and after renal transplantation. Treatment of ASB is required for above situations. We report an 11-year-old-girl with neurogenic bladder who made clean intermittent catheterization and had Pasteurella aerogenes as an ASB agent.

Effects of cleaning and disinfection of thermoplastic masks on hospital infection in patients receiving precise radiotherapy for nasopharyngeal carcinoma

Objective To investigate the effects of cleaning and disinfection of thermoplastic masks on the hospital infection in patients receiving precise radiotherapy for nasopharyngeal carcinoma (NPC). Methods A prospective study was performed among 102 patients receiving precise radiotherapy for NPC from 2013 and 2016, consisting of 18 patients with early-stage (I, Ⅱ) disease and 84 patients with advanced (Ⅲ, IV) disease. All patients were randomly divided into group A and group B using a random number table. For group A, the marker lines of thermoplastic masks were sandwiched by double plastic tapes; cleaning and disinfection plus ultraviolet (UV) disinfection were applied to the masks 1 h prior to radiotherapy and immediately after radiotherapy. For group B, only conventional UV disinfection was applied to the masks. The surface of the masks was examined and hospital infection during radiotherapy was evaluated. Results At the 18th radiotherapy, group A had a significantly lower mask surface colony count than group B (7.90±6.50 vs. 139.05±129.29 CFU/cm2,P=0.000). Group A also had a significantly lower incidence of hospital infection than group B (72.5% vs. 88.2%, P=0.046). For the patients with early stage NPC, particularly, there was no significant difference in the incidence of infection between the two groups (55.6% vs. 66.7%, P=0.629). For patients with advanced NPC, group A had a significantly lower incidence of infection than group B (76.2% vs. 92.9%, P=0.035). There were no significant differences in incidence rates of oral mucosal, skin, and respiratory system infections between the two groups (47.1% vs. 51.0%, P=0.692; 17.6% vs. 23.5%, P=0.463; 7.8% vs. 13.7%, P=0.338). In both groups A and B, the incidence of oral mucosal infection was significantly higher than the incidence rates of skin infection (P=0.001, 0.000) and respiratory system infection (P=0.004, 0.000). Conclusions Thermoplastic mask is one of the risk factors for hospital infection in patients receiving precise radiotherapy for NPC. Timely cleaning and disinfection plus UV disinfection can significantly reduce the surface colony count and the incidence of hospital infection in patients with NPC, particularly in those with advanced NPC receiving precise radiotherapy. The incidence of hospital infection is the highest in the oral mucosa, followed by the skin and the respiratory system. Key words: Thermoplastic mask; Cleaning disinfection; Hospital infection; Nasopharyngeal neoplasms/radiotherapy

Biopreservative effect of bacteriocin in fruit juice preservation

This study aimed to evaluate the biopreservation activity of bacteriocin against some spoilage organisms. This bacteriocin was produced by lactic acid bacteria (LAB) isolated from dahi samples. Man Rogosa Sharpe (MRS) broth and agar were used for the isolation of LAB from the dahi. Bacteriocins are antibacterial proteins produced by bacteria that kill or inhibit the growth of other pathogenic and spoilage bacteria. Many lactic acid bacteria produce a high diversity of different bacteriocins. This study was conducted to produce the bacteriocin which produced by Lactobacillus spp. from dahi sample. Dahi samples were collected from different retailer shops of Chittagong Metropolitan Area (CMA). Lactobacillus spp. was isolated from these dahi samples by using MRS broth (Hi-Media, India) at 37ºC for 48 h. The crude bacteriocin was produced and purified by ammonium sulphate precipitation. The adversary properties of bacteriocin were perused by agar well diffusion method. The durability of bacteriocin was studied in different temperature and pH. The bacteriocin was stable at 37ºC and acidic pH. The antimicrobial activity of the isolates was done by growth inhibition test against some selected pathogenic microorganisms likely Escherichia coli, Pseudomonas aeroginosa, Salmonella paratyphi. The result showed that the isolates of Lactobacillus spp. inhibited the growth of these pathogenic organisms. By this study the antibacterial efficacy of bacteriocin was determined for fresh orange juice. The biopreservative effect of bacteriocin was observed on the basis of low colony counts in total plate count agar (TPA). The study result showed that bacteriocin producing Lactobacillus spp. can be successfully used as biopreservative for fruit juice preservation.&#x0D; Asian Australas. J. Biosci. Biotechnol. 2016, 1 (3), 435-440

Efficacy of chlorine dioxide disinfection to non-fermentative Gram-negative bacilli and non-tuberculous mycobacteria in a hospital water system

Chlorinated tap water in hospitals often contains low levels of non-fermentative Gram-negative bacilli (NFGNB) and non-tuberculous mycobacteria (NTM). Measures are needed to ensure a safe water supply in hospitals to prevent nosocomial infections from these waterborne pathogens. To evaluate the efficacy of ClO2 treatment of a hospital water system on the levels of NFGNB and NTM in the water. Our institution is a 1000-bed medical centre with two main buildings (B1 and B2). B1 has three intensive care units (ICUs) and transplant wards and polyethylene water pipes. B2 (control) has no ICUs and galvanized water pipes. A ClO2 generating unit was installed in the water system of B1 in April 2012 and water samples were collected in B1 and B2 before and eight times after installation. All samples were cultured for NFGNB and NTM. The ClO2 concentration was significantly lower in the hot water than in the cold water (P<0.001). After 40 weeks of ClO2 use, the overall NFGNB colonies decreased significantly (hot water: 160±143 vs 2±4cfu/mL, P<0.001; cold water: 108±138 vs 3±7cfu/mL, P<0.001). Highly prevalent nosocomial NFGNB, such as Pseudomonas spp. and Stenotrophomonas spp., were undetected three months after ClO2 disinfection; Sphingomonas spp. persisted but had lower colony counts. NTM was present in 25% (three out of 12) of sampling locations initially, but was not detected at two weeks after ClO2 disinfection. The ICUs had no overall change in the number of NFGNB nosocomial infections after the intervention. Addition of a ClO2 disinfection unit to our hospital water system reduced the numbers of NTM and NFGNB in the hot and cold water systems.

Active surveillance cultures: comparison of inguinal and rectal sites for detection of multidrug-resistant bacteria

Rectal swabs are the most widely used surveillance technique for detecting multidrug-resistant bacteria colonizing the intestinal tract. Obtaining these samples may cause embarrassment and discomfort to patients. Prior studies indicate that perirectal swabs are as sensitive and specific as rectal swabs with greater patient acceptance. To compare inguinal and rectal swabs for the detection of multidrug-resistant bacteria colonizing the intestinal tract. An epidemiological, comparative, prospective, and controlled study was undertaken with 102 Brazilian patients. Inguinal and rectal swabs were collected for culture and compared. Compared to rectal swabs, the sensitivity and specificity of inguinal swabs was 91.8% and 88.7%, respectively. Even when there were low colony counts from rectal samples, there were more than 100 colonies from inguinal samples. The inguinal region can be considered an acceptable alternative for collecting surveillance cultures for multidrug-resistant bacteria colonizing the intestinal tract. The inguinal swab technique is sensitive and specific for assessing multidrug-resistant micro-organisms, less embarrassing for patients, and simple to implement in hospital practice.