Yeast Colonization Research Articles

The Efficacy and Safety of Sertaconazole Cream (2 %) in Diaper Dermatitis Candidiasis

AimDiaper dermatitis (DD) is an inflammatory irritating condition that is common in infants. Most cases are associated with the yeast colonization of Candida or diaper dermatitis candidiasis (DDC), and therefore, the signs and symptoms improve with antimycotic treatment. Sertaconazole is a broad-spectrum third-generation imidazole derivative that is effective and safe for the treatment for superficial mycoses, such as tineas, candidiasis, and pityriasis versicolor. Our goal was to assess the efficacy and safety of sertaconazole cream (2 %) in DDC.Materials and methodsTwenty-seven patients with clinical and mycological diagnosis of DDC were enrolled and treated with 2 daily applications for 14 days and were followed-up for 2 further weeks.ResultsThree etiologic agents were isolated: Candida albicans in 88.8 %, Candida parapsilosis in 7.3 %, and Candida glabrata in 3.2 %. There was an average symptom reduction from 7.1 to 3.2 in the middle of treatment and to 1.2 and 0.4 units at the end of treatment and follow-up, respectively. The treatment evaluation at the end of the follow-up period showed a total clinical and mycological cure in 88.8 %, improvement in 3.7 %, and failure in 7.4 %. There was side effect (3.7 %) of skin irritation, but the drug was not discontinued.ConclusionsBased on its safety and effectiveness, sertaconazole cream may be considered a new alternative for DDC treatment.

Asymptomatic oral yeast carriage and antifungal susceptibility profile of HIV-infected patients in Kunming, Yunnan Province of China

BackgroundOral Candida colonization and its relation with predisposing factors in HIV-infected patients have received wide concerns during recent decades. In this study, we investigated asymptomatic oral Candida carriage rate, species distribution and antifungal susceptibility of 604 HIV-infected patients and 851 healthy individuals in Kunming, Yunnan Province of China.MethodsMucosal swab sampling was taken from each subject and CHROMagar Candida agar medium and API 20C AUX system were used to identify yeast isolates. In vitro antifungal susceptibility was tested by the broth microdilution method according to the M27-A2 document of the Clinical and Laboratory Standard Institute (CLSI).ResultsThe oral yeast colonization rate in HIV-infected patients (49.5%) was higher than that of healthy subjects (20.7%). Candida albicans constituted the most frequent species, accounting for 82.2% of yeast isolates. The remaining species were composed of C. glabrata, C. parapsilosis, C. krusei, C. tropicalis, C. rugosa, C. norvegensis, Pichia ohmeri and Saccharomyces cerevisiae. In HIV-infected patients, asymptomatic oral yeast colonization was associated with low CD4 cell count (<200 cells/mm3) and lack of highly active antiretroviral therapy (HAART). Different Candida species isolated from our samples presented different susceptibility to voriconazole, fluconazole and itraconazole. Amphotericin B had the best inhibiting effect for all isolates.ConclusionOral yeast colonization in Han Chinese patients with HIV from Kunming had common and unique features and was associated with CD4 cell number and HARRT. Amphotericin B should be used with first priority in controlling Candida infection in Han Chinese patients from Kunming. Our results provide first hand information on monitoring oral yeasts colonization in HIV-infected patients from Kunming, China.

Microbiology and epidemiology of oral yeast colonization in hemopoietic progenitor cell transplant recipients

We monitored the epidemiology and microbiology of oral yeast colonization in patients undergoing hemopoietic progenitor cell transplantation (HPCT) to examine associations between yeast colonization and oral mucositis. One hundred twenty-one consecutive HPCT patients were sampled for oral yeasts prior to fluconazole (FLC) prophylaxis, at transplantation, and weekly until discharge. Clinical oral mucositis screenings were performed triweekly. Yeast colonization was evident at 216 of 510 total visits. Candida albicans and Candida glabrata were the predominant organisms. Eight patients showed elevated minimal inhibitory concentrations to FLC. One patient developed fungal septicemia. Patients with oral mucositis assessment scale scores <20 had higher colonization rates than those with higher scores. FLC is effective in controlling a variety of oral yeasts in HPCT recipients. FLC-resistant yeasts do emerge and can be the source of fungal sepsis. A positive association was not shown between yeast colonization and the presence or severity of oral mucositis.

Measurement wettability of maxillofacial silicones

Maxillofacial silicone is an important material in maxillofacial prostheses clinics. However there is probability of yeast colonization on maxillofacial silicones. This situation increases the risk of a second infection of patients whose general health status is usually poor. This study was to measurement of surface contact-angle thus wettability and adhesion of microorganisms of three different maxillofacial silicone materials (VST-50F, A-2006, A-2186) Three different instance of silicone material were measured by the droplet method and surface contact-angle measuring device. The results obtained were analyzed statistically by Kruskal Wallis and the Mann-Whitney U test. It was determined that there were statistically differences between the groups (p=0.00010). In conclusion; the wettability of silicone samples was determined descending in VST-50F, A-2006 and A-2186.

Association of subgingival colonization of Candida albicans and other yeasts with severity of chronic periodontitis

The aim of this study is to analyze the relationship between the subgingival colonization by Candida albicans and other yeasts with the severity of chronic periodontitis (CP). After sample size calculation, 40 patients with CP and 20 healthy subjects (HS) were included in the study. Cases of slight-moderate (MCP, n = 23) and severe CP (SCP, n = 17) were defined according to the Centers for Disease Control/American Association of Periodontology classification. Subgingival samples were acquired using sterile paper-points from the sulcus or the deepest periodontal pocket of each healthy and subject with CP, respectively, and were cultured aerobically on three selective media. Yeast colonies that grew on the surface of plates were later identified by biochemical reactions. Statistical tests were used to analyze the association between subgingival yeast colonization (number of yeast-positive individuals and colony forming units (CFU) per subject) and periodontal disease status, considering statistical significance when P < 0.05. Although several yeast species were found (C. parapisilosis, Rhodotorula sp., C. dubliniensis and C. tropicalis), only C. albicans was present in all the patients with yeast-positive CP. Twelve patients (30%) with CP presented yeasts in the subgingival biofilm while only three patients (15%) in the HS group were positive for these microorganisms. No statistical difference was found between the CP and HS groups (P = 0.084). However, when the CP group was divided on the basis of severity, statistical differences were observed between the SCP and MCP groups (47% vs. 17%, P = 0.043), and between the SCP and HS groups (47% vs. 15%, P = 0.033). No statistical difference was observed between the MCP and HS groups (17% vs. 15%, P = 0.832). High densities of yeasts were found only in patients with MCP and SCP (mean and range 61.25 (0-100) CFU/plate and mean and range 51 (0-101) CFU/plate, respectively). In this group of patients, subgingival colonization of some yeasts, especially C. albicans, was associated with the severity of CP.

Predisposing factors for oropharyngeal colonization of yeasts in human immunodeficiency virus-infected patients: A prospective cross-sectional study

Oropharyngeal candidiasis continues to be a major opportunistic infection in human immunodeficiency virus (HIV)-infected patients. The objectives of this study were to investigate the prevalence, associated factors, and microbiologic features for oropharyngeal yeast colonization in HIV-infected patients. From October to December 2009, consecutive HIV-infected patients older than 18 years were recruited in this study. Demographic information, underlying conditions, and clinical histories were collected. Oropharyngeal swab cultures for yeasts and antifungal drug susceptibilities of the isolates were performed. Of the 105 HIV-infected patients, 54 (51.4%) were colonized with yeasts, including 11 patients (20.4%) with more than one species. Among the 68 isolates, Candida albicans accounted for 73.5%, followed by Candida tropicalis (5.9%), Candida glabrata (5.9%), and Candida dubliniensis (4.4%). There were 7.5% and 6% Candida isolates resistant to fluconazole and voriconazole, respectively. All of the Candida isolates were susceptible to amphotericin B. A higher prevalence of yeast colonization was noted in patients with a CD4 cell count ≤200 cells/μL (p = 0.032). Multivariate regression analysis showed that intravenous drug use was an independent associated factor for oropharyngeal yeast colonization (odds ratio, 5.35; 95% confidence interval, 1.39-20.6; p = 0.015), as well as protease inhibitor-containing antiretroviral therapy (odds ratio, 3.59; 95% confidence interval, 1.41-9.12; p = 0.007). Despite previous studies showing that protease inhibitors decreased Candida adhesion to epithelial cells in vitro, the current study found protease inhibitor-containing antiretroviral therapy predisposed to oropharyngeal yeast colonization in HIV-infected patients.

Oropharyngeal yeast colonization in HIV-infected outpatients in southern Taiwan: CD4 count, efavirenz therapy and intravenous drug use matter

To understand the status of oropharyngeal yeast colonization in human immunodeficiency virus (HIV) -infected outpatients in the era of highly active antiretroviral therapy (HAART), we conducted a prospective, cross-sectional study from October 2009 to January 2010 at a medical centre in southern Taiwan. Fungal cultures of the oropharyngeal swabs were performed on 327 enrolled patients. At enrolment, 258 (79%) patients had been receiving HAART, and 42 (12.8%), 73 (22.3%) and 212 (64.8%) patients had CD4 cell counts ≤200, 201–350, and >350 cells/mm3, respectively. Oral yeast colonization was detected in 193 (59%) patients, among whom 157 (81.3%), 25 (13.0%), and 11 (5.7%) were colonized by a single, two and more than two species, respectively. Multivariate analysis showed that receipt of efavirenz-containing regiments and CD4 cell counts >200 cells/mm3 were associated with lower risks of oral yeast colonization, while intravenous drug users were at a higher risk. Among the 241 isolates recovered, Candida albicans accounted for 69.7%, followed by C. dubliniensis (9.5%), C. glabrata (8.3%), C. tropicalis (3.3%), C. intermedia (2.1%), C. parapsilosis (1.7%), and 11 other species (5.4%). Overall, 230 (95.4%), 236 (97.9%) and 240 (99.6%) isolates were susceptible to fluconazole, voriconazole and amphotericin B, respectively. In conclusion, colonization by C. dubliniensis has emerged in recent years. In addition to a CD4 cell count ≤200 cells/mm3, which is a known risk factor for oropharyngeal yeast colonization in HIV-infected patients that was identified in our previous studies, two risk factors, non-receipt of efavirenz-based combinations and intravenous drug use, were first identified in the present study. Fluconazole remained effective in vitro against the yeasts colonizing the oropharynx in this population.

The Changing Epidemiology of Oropharyngeal Candidiasis in Patients with HIV/AIDS in the Era of Antiretroviral Therapy.

The impact of antiretroviral therapy (ART) on opportunistic conditions in HIV patients continues to evolve. We specifically studied the changing epidemiology of oropharyngeal candidiasis (OPC) in 215 HIV/AIDS patients. Status of yeast colonization was assessed from oral rinse samples, and preliminary yeast identification was made using CHROMagar Candida and confirmed with standard microbiological techniques and/or molecular sequencing. Susceptibility to fluconazole was determined by CHROMagar Candida agar dilution screening and CLSI broth microdilution. 176 (82%) patients were colonized and 59 (27%) patients had symptomatic OPC. Candida albicans was the most prevalent species, though C. glabrata and C. dubliniensis were detected in 29% of isolates. Decreased fluconazole susceptibility occurred in 10% of isolates. Previous ART reduced the risk of OPC, while smoking increased the risk of colonization. Oral yeast colonization and symptomatic infection remain common even with advances in HIV therapy. C. albicans is the most common species, but other yeasts are prevalent and may have decreased susceptibility to fluconazole.

Características clínicas e epidemiológicas de doentes com cateter venoso central colonizado por leveduras.

Among others complications due central venous catheters (CVCs), the blood infection (BI) deserves particular attention. The purposes of this study were to analyze the clinical and epidemiological characteristics of adult patients using CVC; to know the yeast colonization index; and to link it to risk factors for BI. Yeasts were investigated in 156 CVCs removed from 91 patients of the Regional University Hospital of Maringá from February to August, 2008. Yeast colonization was detected in 10.89% of the catheters, which were removed from 15 patients, three of them had a fatal hospital yeast infection due to catheter. There was a preponderance of male subjects; median age was 66 years and the mean hospitalization time was 15 days, greater than that of the non-colonized (p = 0.003). The mortality rate was significantly greater in this group than among those with non-colonized catheters (p = 0.01). Total parenteral nutrition and hemodialysis were the risk factors significantly more frequent in this group (p = 0.002 and 0.001, respectively). The most frequently found yeast was Candida parapsilosis. Among the colonized catheters those of double-lumen for infusion predominated and the site of insertion was the right subclavian vein. In conclusion the colonization by yeasts rate of CVC was 10.89% and 20% of them resulted in infection. These results add to higher mortality in patients who CVC was colonized by yeasts deserve attention considering the increasing of the hospital fungal infections.

Effect of a multipurpose disinfecting solution containing Polyquat and Alexidine on contamination of contact lens cases during use

Purpose: Silver-infused contact lenses (CLs) may provide benefits to CL wearers by reducing adherence of potential pathogens to CL surfaces; however, they have the potential to modify the normal ocular biota during wear. This study investigated the effect of silverinfused silicone hydrogel CLs on conjunctival flora over six months of daily wear (DW). Method: A prospective, randomised, doublemasked, contralateral study was conducted. Sixty subjects were randomly assigned to wear silverinfused (galyfilcon A with incorporated silver ions, test) and standard (galyfilcon A, control) silicone hydrogel CLs on a contralateral basis for six months of DW. Prior to assignment of the test and control CLs, all subjects were fitted with etafilcon A daily disposable CLs for a one week wearin period. Conjunctival flora were cultured at screening/pre-baseline (with subjects’ habitual CLs), baseline (after daily disposable wear) and four weeks, three and six months following commencement of test and control CL wear, using sterile calcium alginate swabs moistened with sterile unpreserved 0.9% saline. Results: There were no statistically significant differences between the conjunctivae of test and control eyes in incidence of positive cultures (p>0.05), culture classification grades (p>0.05), microorganism levels (p>0.05) or numbers of different types of microorganisms isolated (p>0.05). Wear of the test CLs did not promote fungal or yeast colonisation of the conjunctivae. The most frequently isolated microorganisms were Gram-positive bacteria considered to be part of the normal ocular flora. Conclusions: Wear of the silver-infused CLs did not result in any statistically or clinically significant alterations to the ocular biota over six months of DW.

Influence of care system and wearing modality on clinical performance of a single silicone hydrogel contact lens

Purpose: Silver-infused contact lenses (CLs) may provide benefits to CL wearers by reducing adherence of potential pathogens to CL surfaces; however, they have the potential to modify the normal ocular biota during wear. This study investigated the effect of silverinfused silicone hydrogel CLs on conjunctival flora over six months of daily wear (DW). Method: A prospective, randomised, doublemasked, contralateral study was conducted. Sixty subjects were randomly assigned to wear silverinfused (galyfilcon A with incorporated silver ions, test) and standard (galyfilcon A, control) silicone hydrogel CLs on a contralateral basis for six months of DW. Prior to assignment of the test and control CLs, all subjects were fitted with etafilcon A daily disposable CLs for a one week wearin period. Conjunctival flora were cultured at screening/pre-baseline (with subjects’ habitual CLs), baseline (after daily disposable wear) and four weeks, three and six months following commencement of test and control CL wear, using sterile calcium alginate swabs moistened with sterile unpreserved 0.9% saline. Results: There were no statistically significant differences between the conjunctivae of test and control eyes in incidence of positive cultures (p>0.05), culture classification grades (p>0.05), microorganism levels (p>0.05) or numbers of different types of microorganisms isolated (p>0.05). Wear of the test CLs did not promote fungal or yeast colonisation of the conjunctivae. The most frequently isolated microorganisms were Gram-positive bacteria considered to be part of the normal ocular flora. Conclusions: Wear of the silver-infused CLs did not result in any statistically or clinically significant alterations to the ocular biota over six months of DW.

The effect of silver-infused silicone hydrogel contact lenses on the ocular biota during daily wear

Purpose: Silver-infused contact lenses (CLs) may provide benefits to CL wearers by reducing adherence of potential pathogens to CL surfaces; however, they have the potential to modify the normal ocular biota during wear. This study investigated the effect of silverinfused silicone hydrogel CLs on conjunctival flora over six months of daily wear (DW). Method: A prospective, randomised, doublemasked, contralateral study was conducted. Sixty subjects were randomly assigned to wear silverinfused (galyfilcon A with incorporated silver ions, test) and standard (galyfilcon A, control) silicone hydrogel CLs on a contralateral basis for six months of DW. Prior to assignment of the test and control CLs, all subjects were fitted with etafilcon A daily disposable CLs for a one week wearin period. Conjunctival flora were cultured at screening/pre-baseline (with subjects’ habitual CLs), baseline (after daily disposable wear) and four weeks, three and six months following commencement of test and control CL wear, using sterile calcium alginate swabs moistened with sterile unpreserved 0.9% saline. Results: There were no statistically significant differences between the conjunctivae of test and control eyes in incidence of positive cultures (p>0.05), culture classification grades (p>0.05), microorganism levels (p>0.05) or numbers of different types of microorganisms isolated (p>0.05). Wear of the test CLs did not promote fungal or yeast colonisation of the conjunctivae. The most frequently isolated microorganisms were Gram-positive bacteria considered to be part of the normal ocular flora. Conclusions: Wear of the silver-infused CLs did not result in any statistically or clinically significant alterations to the ocular biota over six months of DW.

Differences in ocular physiological changes over time during daily silicone hydrogel contact lens wear with various care systems

Purpose: Silver-infused contact lenses (CLs) may provide benefits to CL wearers by reducing adherence of potential pathogens to CL surfaces; however, they have the potential to modify the normal ocular biota during wear. This study investigated the effect of silverinfused silicone hydrogel CLs on conjunctival flora over six months of daily wear (DW). Method: A prospective, randomised, doublemasked, contralateral study was conducted. Sixty subjects were randomly assigned to wear silverinfused (galyfilcon A with incorporated silver ions, test) and standard (galyfilcon A, control) silicone hydrogel CLs on a contralateral basis for six months of DW. Prior to assignment of the test and control CLs, all subjects were fitted with etafilcon A daily disposable CLs for a one week wearin period. Conjunctival flora were cultured at screening/pre-baseline (with subjects’ habitual CLs), baseline (after daily disposable wear) and four weeks, three and six months following commencement of test and control CL wear, using sterile calcium alginate swabs moistened with sterile unpreserved 0.9% saline. Results: There were no statistically significant differences between the conjunctivae of test and control eyes in incidence of positive cultures (p>0.05), culture classification grades (p>0.05), microorganism levels (p>0.05) or numbers of different types of microorganisms isolated (p>0.05). Wear of the test CLs did not promote fungal or yeast colonisation of the conjunctivae. The most frequently isolated microorganisms were Gram-positive bacteria considered to be part of the normal ocular flora. Conclusions: Wear of the silver-infused CLs did not result in any statistically or clinically significant alterations to the ocular biota over six months of DW.

Treatment with probiotics in experimental oral colonization by Candida albicans in murine model (DBA/2)

The aim of this study is to evaluate the oral colonization by Candida albicans in experimental murine immunosuppressed DBA/2 and treatment with probiotic bacteria. To achieve these objectives, 152 DBA/2-immunosuppressed mice were orally inoculated with a suspension of C. albicans containing 10(8) viable yeast cells, the animals were treated with nystatin or with the probiotics (Lactobacillus acidophilus and Lactobacillus rhamnosus). Evaluations were performed by Candida count from oral mucosa swabbing. The oral mucosa colonization by C. albicans started at day 1 after inoculation, remained maximal from day 3 until day 7, and then decreased significantly. Probiotics reduced the C. albicans colonization significantly on the oral mucosa in comparison with the untreated animal group. In the group treated with L. rhamnosus, the reduction in yeast colonization was significantly higher compared with that of the group receiving nystatin. Immunosuppressed animal model DBA/2 is a relevant model for experimental Candida oral colonization, and the treatment with probiotics in this model may be an effective alternative to prevent it.

Ecological structuring of yeasts associated with trees around Hamilton, Ontario, Canada

This study seeks to determine the distribution and diversity of yeasts in and around the Hamilton area in Canada. In light of the increasing number of fungal infections along with rising morbidity and mortality rates, especially among the immunocompromised, understanding the diversity and distribution of yeasts in natural environments close to human habitations has become an increasingly relevant topic. In this study, we analyzed 1110 samples obtained from the hollows of trees, shrubs and avian droppings at 8 geographical sites in and around Hamilton, Ontario, Canada. A total of 88 positive yeast strains were isolated and identified belonging to 20 yeast species. Despite the relative proximity of the sampling sites, our DNA fingerprinting results showed that the yeast populations were highly heterogenous. Among the 14 tree species sampled, cedar, cottonwood and basswood hollows had relatively high yeast colonization rates. Interestingly, Candida parapsilosis was isolated almost exclusively from Pine trees only. Our results are consistent with microgeographic and ecological differentiation of yeast species in and around an urban environment.

Yeast Flora in Oropharyngeal and Rectal Mucous Membranes of Healthy and Critically Ill Neonatal Foals

Little is known about the normal or pathologic yeast flora in healthy and critically ill neonatal foals. The aims of this study were to evaluate the yeast flora colonizing the mucous membranes of the digestive tract (oropharynx and rectum mucous membranes) of healthy and hospitalized foals and to find out risk factors involved in yeast colonization of foals referred to a neonatal intensive care unit. A total of 240 swabs were collected from 21 healthy (group A) and 39 sick (group B) foals. In 14 of the 60 foals, yeast was isolated in at least one sample (23.3%): 3 of the 21 foals (14.3%) were positive in group A and 11 of 39 foals (28.2%) were positive in group B. The yeasts were isolated from rectal swabs obtained from none in healthy foals, whereas 5 of the 39 sick foals were positive; however, this difference was not statistically significant. No significant difference was also detected regarding oropharyngeal swabs between healthy (3/21) and sick (10/39) foals. The risk factors significantly associated with the isolation of yeasts from rectal swabs were female sex, treatment with oral antibiotics, and stressful diagnostic–therapeutic procedures. The only risk factor significantly associated with the isolation of yeast from oropharyngeal swabs was the treatment with antacids and gastroprotectants. The results show that fungi present in the gastrointestinal tract of neonatal foals were mainly environmental yeasts and suggested the absence of a stable fungal colonization. Candida was the genus frequently isolated in hospitalized foals, just as it is isolated in critically ill human neonates.

Epidemiology and Etiology of Denture Stomatitis

Denture stomatitis, a common disorder affecting denture wearers, is characterized as inflammation and erythema of the oral mucosal areas covered by the denture. Despite its commonality, the etiology of denture stomatitis is not completely understood. A search of the literature was conducted in the PubMed electronic database (through November 2009) to identify relevant articles for inclusion in a review updating information on the epidemiology and etiology of denture stomatitis and the potential role of denture materials in this disorder. Epidemiological studies report prevalence of denture stomatitis among denture wearers to range from 15% to over 70%. Studies have been conducted among various population samples, and this appears to influence prevalence rates. In general, where reported, incidence of denture stomatitis is higher among elderly denture users and among women. Etiological factors include poor denture hygiene, continual and nighttime wearing of removable dentures, accumulation of denture plaque, and bacterial and yeast contamination of denture surface. In addition, poor-fitting dentures can increase mucosal trauma. All of these factors appear to increase the ability of Candida albicans to colonize both the denture and oral mucosal surfaces, where it acts as an opportunistic pathogen. Antifungal treatment can eradicate C. albicans contamination and relieve stomatitis symptoms, but unless dentures are decontaminated and their cleanliness maintained, stomatitis will recur when antifungal therapy is discontinued. New developments related to denture materials are focusing on means to reduce development of adherent biofilms. These may have value in reducing bacterial and yeast colonization, and could lead to reductions in denture stomatitis with appropriate denture hygiene.

EFFICACY OF SODIUM HYPOCHLORITE AND QUATERNARY AMMONIUM COMPOUNDS ON YEASTS ISOLATED FROM APPLE JUICE

ABSTRACTIn this work, we evaluated the effectiveness of sodium hypochlorite and a commercial quaternary ammonium compound against four wild yeast strains in their different growth forms: planktonic, sessile and forming microcolonies. These yeasts had been isolated from apple juice processing plant, and appropriate environmental conditions were employed throughout the work. For planktonic cells, 4 log reduction was obtained using the lowest concentration of sodium hypochlorite (200 ppm) on all tested strains. However, quaternary ammonium chloride was effective only on Zygosaccharomyces sp. in all in‐use concentrations tested, and only the stronger in‐use concentration (1:30) was effective on Rhodotorula mucilaginosa. Because of the above results, the disinfection on sessile yeast cells was performed only with sodium hypochlorite solutions. In cells attached in batch conditions, the highest concentration of sodium hypochlorite (500 ppm) was necessary to get 4 log reduction. In order to obtain a 3 log reduction on Zygosaccharomyces sp. microcolonies formed in laminar flow conditions, the combined action of 0.5% w/v NaOH and 500 ppm sodium hypochlorite was required. We concluded, thus, that cells forming microcolonies under laminar flow conditions were less susceptible to disinfectants than those suspended or attached in batch conditions. These results also indicated that attachment and colonization of autochthonous yeasts must be properly identified to evaluate the effectiveness of disinfectants used in apple juice processing plants.PRACTICAL APPLICATIONSBiofilm formation is a serious hygienic problem in food industry. In fruit processing plants, the microbial attachment causes serious engineering problems such as decreases in permeate flow in membrane processes, greatly reducing operating efficiency of ultrafiltration process. Moreover, the presence of microorganisms attached to food contact surfaces could increase the fluid frictional resistance of surfaces, increases the corrosion rate of surfaces leading to energy and production losses and compromises the hygienic quality of the final product causing significant economic losses. Our results show that the evaluation of the effectiveness of a disinfectant on biofilms should be performed using a method where the adhesion and colonization of cells was carried out in flow conditions similar to those of the environment where the disinfectant is applied. We observed that even when using new surfaces, and performing both cleaning and sanitizing under optimal conditions, the risk that the number of viable cells remaining on the surface can generate a new biofilm subsists.

Oral Candida isolates among HIV-infected subjects in Nigeria

Nigeria is a West African country of more than 150 million persons with the second highest case of HIV/AIDS infected patients in the world. The species spectrum of oral yeast colonization and the susceptibility to a wide range of antifungal agents is poorly understood in Nigeria especially in the south east, south south, and the northern axis. This study evaluates the species spectrum of oral colonization by Candida species in HIV-infected patients in Nigeria and the in vitro susceptibility pattern of the Candida isolates to a broad range of antifungal agents. Two hundred oropharyngeal swabs from HIV-infected patients and 100 age-matched healthy controls were screened for yeast isolates using standard procedures and confirmed by the analytical profile index 20C along with other biochemical tests. In vitro susceptibility testing of the yeast isolates to antifungals were performed using the broth microdilution method protocol recommended by the Clinical Laboratory Scientific Institute. Of 200 patients screened, 120 (60%) were colonized by yeasts. C albicans was the dominating species in both groups with 54 (45%) isolated from HIV subjects. The non-albicans Candida species accounted for 55% with C tropicalis 22 (18.3%) showing the highest frequency. We observed that 11.7% of all yeasts isolates were resistant to fluconazole, 8.3% to flucytosine, 7.5% to itraconazole, and 1.7% to voriconazole. All isolates were susceptible to amphotericin B and most of them demonstrated very low voriconazole minimal inhibitory concentrations. Apart from C albicans, C tropicalis and C parapsilosis isolates were also recovered from apparently healthy control subjects. Although C albicans continues to be the dominant Candida species in oral Candida carriage of HIV-infected patients in Nigeria, the nonalbicans Candida species are increasing. Furthermore, the finding of resistant isolates in our study emphasizes the need for antifungal susceptibility testing whenever antifungal treatment is desired especially in HIV-infected subjects.

The effect of polyvinylpyrrolidone-sodium hyaluronate gel (Gelclair) on oral microbial colonization and pain control compared with other rinsing solutions in patients with oral mucositis after allogeneic stem cells transplantation

SummaryBackgroundGelclair is an oral lubricating gel used in the management of oral mucositis (OM). We evaluated its efficacy, tolerance and impact on oral cavity microbial colonization in patients with OM after allogeneic hematopoietic stem cells transplantation.Material/MethodGelclair was administered in a group of 22 patients with active OM. A control group of 15 patients used other rinsing solutions (chlorhexidine, benzydamine, salvia). Tests with oral cavity swabs for microbiology analysis were performed once a week.ResultsThe characteristics of OM in both groups were comparable, and rinsing solutions had satisfactory tolerability. There was no difference in the median improvement of oral intake and OM-related pain relief, which was assessed mostly as “slight effect”. In the Gelclair group, the effect duration was longer (median 3 [0–5] vs. 1 [0–3] hours, p=0.001). There was significant increase of Enterococcus faecalis and Candida sp. colonization of the oral cavity over the course of the hospitalization and significantly reduced incidence of such colonization in patients with OM in the Gelclair group: 1/22 (5%) vs. 6/15 (40%), p=0.01. In vitro tests showed inhibited growth of Enterococcus faecalis and Candida sp. colonies within the area of the Gelclair application.ConclusionsGelclair may be individually helpful in the management of OM and pain in patients after allogeneic stem cells transplantation. Its use did not lead to worsened oral bacterial and yeast colonization and probably even helped to protect mucosa from Enterococcus and Candida sp. Further studies based on larger cohorts are needed.