Tissue Culture Tube Research Articles

Study of biofilm formation among uropathogens isolated from catheter-associated UTI patient from a tertiary care hospital

Background: Catheter-associated urinary tract infection (CAUTI) is a serious health threat and challenging infection. CAUTI accounts for up to 40% of all nosocomial infections. Biofilm provides a survival strategy to microorganisms and ultimately leads to re-infections and recurrence of urinary tract infections (UTI) despite a full course of antibiotics. Aims and Objectives: The present study was conducted to determine the prevalence of CAUTI in suspected UTI patients and prevalence of biofilm-forming uropathogens among CAUTI patients. Materials and Methods: The cross-sectional study was done over a period of 6 months among 95 catheterized CAUTI patients. Biofilm production among isolated uropathogens was tested by tissue culture plate, tube test, and congo red agar method. Isolates were identified as biofilm producer if they were tested positive by any one of the all four methods, and isolates were considered biofilm non-producer in consensus with all four methods. Results: In this study, the prevalence of CAUTI was 68.42%. Among 65 isolates most common uropathogen was 28 (43.07%) Escherichia coli. In this present study, the prevalence of biofilm-forming uropathogens was 58.46% (38). Tissue culture plate was the most sensitive (97.36%) method in detecting biofilm formation followed by modified congo red agar (82.21%), congo red agar (71.05%), and tube test (65.78%). Biofilm productions were significantly associated with female gender, diabetes, and prolonged catheterization. Conclusion: Indwelling urinary catheter acts as a nidus for biofilm formation among microorganisms. Duration of catheterization is inversely associated with UTI. Hence, the need for catheter removal should be assessed daily to prevent infection. Periodic surveillance should be done to detect biofilm formation where prolonged catheterization is inevitable.

Characterization of biofilm formation by Mycobacterium smegmatis during different environmental stress conditions: An in-vitro study

Aim: In-vitro characterisation of biofilm produced by Mycobacterium smegmatis (M. smegmatis), a surrogate model for biofilm production by Mycobacteria, and to evaluate the impact of different environmental stress on mycobacterial growth and biofilm formation. Methodology: M. smegmatis biofilms were studied using tissue culture plate and tube adherence methods. Confocal Laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) were used to study the 3D structure and surface morphology, respectively. Additionally, the effect of different environmental stress, such as the absence of essential ions, exposure to harsh environmental conditions, such as acidic environment or oxidative stress, on mycobacterial biofilm formation and mycobacterial growth was assessed. Results: All the exposures, except for carbon supplemented media had a detrimental effect on the number of viable counts and on biofilm formation by mycobacteria (p<0.001). Growth in low pH and oxidative stress was found to be maximum showing reduction by 98% when compared with control. Interpretation: Our findings present various environmental conditions that profoundly affect biofilm formation and thus, may find practical implications in future as effective mycobacterial control strategies having attributes of mycobacterial growth as well as biofilm inhibition. Key words: Biofilm, Environmental stress, Multi-drug resistance, Mycobacterium

An evaluation of three different biofilm detection methods in orthopedic implant associated infections and its implication in healthcare system

: Biofilms are defined as microbially derived sessile communities characterized by the cells that are irreversibly attached to a substratum. These organisms have been associated with implant associated infectionsThe present study is therefore undertaken 1. To compare the three screening methods used for detection of biofilm formation (Tissue culture plate method, Tube method and Congo red agar method) and 2. To correlate the antibiotic resistance pattern of biofilm producers and non biofilm producers. : A prospective study was carried out in the department of microbiology, on all orthopedic implant associated infections from September 2015 to July 2016 on aspirated pus samples. A total of 120 non repetitive clinical isolates were taken and subjected to biofilm detection. All the bacterial isolates were identified by standard biochemical tests. Antibiotic susceptibility test of bacterial isolates was performed by Kirby Bauer disk diffusion method according to Clinical Laboratory Standard Institute (CLSI) guidelines on Muller Hinton Agar (MHA). A reference strain of Staphylococcus epidermidis ATCC 35984(positive biofilm producer) and Staphylococcus epidermidis ATCC 12228(non biofilm producer) were used as controls. Tissue culture plate method was considered as gold standard as it detected 25% biofilm producers which included 12% weak biofilm producers which was missed by congo red agar (CRA) and tube method (TM). Also, this correlated to methicillin resistant staphylococcus aureus (MRSA), ESBL, amp-c and MDR pattern of antibiogram. : TCP is considered as most reliable screening method for biofilm detection and should be routinely employed to prevent treatment failures as these organisms are intrinsically resistant to many antimicrobials leading to implant associated infections.

Phenotypic Detection of Biofilm Formation in Clinical Isolates of Methicillin-Resistant Staphylococcus aureus

Background: Staphylococcus aureus is one of the common pathogens which causes mild-to-severe diseases. Moreover, its ability to produce biofilm along with drug resistance makes it more notorious and difficult to treat; therefore, early biofilm detection can help in better management of diseases caused by methicillin-resistant S. aureus (MRSA). Materials and Methods: All clinically isolated S. aureus were screened for their antibiotic susceptibility pattern followed by MRSA status by cefoxitin disk-diffusion method. Evaluation of biofilm-producing nature of biofilm was accessed by tissue culture plate (TCP), tube adhesion (TA), and Congo red agar (CRA) methods. Results: Of all S. aureus isolates, 57% had MRSA status. TCP method showed that 68% of MRSA were biofilm producers. TA method showed 55% and CRA method showed 46% biofilm production. Conclusion: Early detection of MRSA and biofilm could be very beneficial to control S. aureus infection. Of all three biofilm detection methods, TCP method was effective in detecting biofilm, followed by TA and CRA methods.

Isolation and molecular identification of biofilm producing P. aeruginosa and K. pneumoniae from urinary tract infections patient urine sample

BackgroundRecent years, multi drug resistant pathogens and their pathogenicity were increased worldwide due to unauthorized consumption of antibiotics. In addition, correlation between multi drug resistant bacteria and biofilm formation is heightened due to the production of more virulence behavior. There is no better identification methods are available for detection of biofilm producing gram negative bacteria. Materials and methodsIn this research work, multi drug resistant strains of Pseudomonas aeruginosa (P. aeruginosa) and Klebsiella pneumoniae (K. pneumoniae) were identified based on the specific antibiotics and third generation cephalosporin discs by disc diffusion assay. Subsequently, biofilm forming ability of selected pathogens were identified tissue culture plate and tube test. Based on the multi-drug resistant ability and biofilm production, the molecular identification of P. aeruginosa and K. pneumoniae were confirmed by PCR using universal primers. Results and conclusionsNo zone of inhibition present around the discs of muller hinton agar plates were confirm, selected P. aeruginosa and K. pneumoniae strains were multi drug resistant pathogens. Performed third generation cephalosporin antibiotics were also highly sensitive to selected pathogens of P. aeruginosa and K. pneumoniae. Further, biofilm forming ability of selected P. aeruginosa and K. pneumoniae was confirmed by tissue culture plate and tube methods. Finally, molecular identification of P. aeruginosa and K. pneumoniae was named as P. aeruginosa and K. pneumoniae. Our result was conclude, selected P. aeruginosa and K. pneumoniae as biofilm producing pathogens and also highly resistant to current antibiotics.

Antimicrobial Resistance and Quorum Sensing Genes Detection among the Biofilm Forming Staphylococcus aureus Isolated from Admitted Patients of Dhaka Medical College Hospital, Dhaka, Bangladesh

Staphylococcus aureus an infamous human pathogen, is a major cause of the community as well as healthcare associated infections. Staphylococcus aureus has the tendency to form biofilm. Biofilm formation usually increases antimicrobial resistance capacity which shows considerable challenges to successful eradication of infections. The aim of this study was to detect the biofilm forming Staphylococcus aureus phenotypically and to determine its association with drug resistance and also detect the prevalence of different types of quorum sensing genes among them. Out of 275 clinical samples, 75.64% were culture positive among which 21.63% Staphylococcus aureus were isolated by culture and biochemical tests. Biofilm producing Staphylococcus aureus were isolated by tissue culture plate method and tube method. Antimicrobial susceptibility tests were performed by the standard disc diffusion technique. PCR was done to detect agr genes and sequencing of agr-I gene was done. Tissue culture plate method was found superior to tube method for biofilm detection. Tissue culture plate method detected 71.11% and tube method detected 62.22% biofilm producers. Biofilm-producing Staphylococcus aureus showed higher resistance to oxacillin 53.13%, cefoxitin 46.88% and ampicillin 46.88% than non biofilm-producers. Among biofilm-producing Staphylococcus aureus, agr-I gene was predominant (46.88%) than other quorum sensing genes. The study provided insight into the higher proportion of antibiotic resistance among non-biofilm-producing Staphylococcus aureus than biofilm-producers. So, antibiotic resistance is not significantly associated with biofilm-production in Staphylococcus aureus.

A microfluidic bubble perfusion device for brain slice culture.

Ex vivo brain slice cultures are utilized as analytical models for studying neurophysiology. Common approaches to maintaining slice cultures include roller tube and membrane interface techniques. The rise of organ-on-chip technologies has demonstrated the value of microfluidic perfusion culture systems for sampling and analysis of complex biology under well-controlled in vitro or ex vivo conditions. A number of approaches to microfluidic brain slice culture have been developed, however these typically involve complex design, fabrication, or operational parameters in order to meet the high oxygen demands of brain slices. Here, we present proof-of-principle for a novel approach to microfluidic brain slice culture. In this system, which we term a microfluidic bubble perfusion device, principles of droplet microfluidics were employed to generate droplets of perfusion media dispersed between bubbles of carbogen gas, and brain tissue slices were perfused with the resulting monodispersed droplets and bubbles. The challenge of tissue immobilization in the flow system was addressed using a two-part cytocompatible carbohydrate-based tissue adhesive. Best practices are discussed for perfusion chamber designs that maintain segmented flow throughout the course of perfusion. Control of droplet and bubble volumes was possible across the range of ca. 4-15 μL, bubble generation frequency was well controlled in the range ca. 1-7 bubbles per min, and bubble duty cycle was well controlled across the range ca. 20-80%. Murine hypothalamic tissue slices containing the suprachiasmatic nuclei were successfully maintained for durations of 8-10 hours, with tissue remaining viable for the duration of perfusion as assessed by Ca2+ imaging and propidium iodide (PI) staining.

Bacterial spectrum in surgical wound infection, its susceptibility pattern and biofilm formation among isolates

Topic: Bacterial spectrum in surgical wound infection, its susceptibility pattern and biofilm formation among isolates. Aim: To identify the spectrum of bacterias associated with wound infection and their antimicrobial susceptibility pattern and biofilm formation. Introduction: Chronic wounds are severe worldwide problem. Wounds are considered chronic when healing fails to proceed normally and anatomic and functional integrity of the skin is not achieved in approximately 1 month. Chronic wound include diabetic foot ulcer, pressure or decubitus ulcer, venous leg ulcer and non-healing surgical site infection.1Annual incidence is of diabetic ulcer in India in a population based study is 1.0 to 4.1% 1. Biofilm formation is widespread in chronic wounds. The biofilm phenotype gives rise to drug resistant strains resulting in treatment failure. Materials and Methods: A prospective study was done at a tertiary care Hospital in North Karnataka for a period of 1 year from February 2017 to January 2018. A total of 241 samples in an age group of 20 to 70 years with history of wound infection attending surgery department were collected with a sterile cotton swab and processed as per CLSI standards.2 Detection of biofilm formation by modified congo red agar method, tissue culture plate method and tube assay method. Results: A total of 241 pus samples were collected. 65.56% (158) showed bacterial growth and 34.43% (83) showed no growth. The study group comprised 139 male and 102 female patients in the ratio of 1.39:1. Age range was 20-70 years Maximum samples were in the age group of 21-30 years. 44.93% (71) of isolates were obtained Gram positive organisms and 55.06 % (87) were Gram negative. Escherichia coli was the predominant isolated organism 16.18% (39). Followed by staphylococcus aureus 9.54% (23). 76 out of 158 sample showed biofilm formation (48.01%). Staphylococcus aureus was dominant biofilm former. 81.57% (62) of biofilm producers were multiple drugs resistant. Conclus

Biofilm-Formation in Clonally Unrelated Multidrug-Resistant Acinetobacter baumannii Isolates

This study analyzed the genotype, antibiotic resistance, and biofilm formation of Acinetobacter baumannii strains and assessed the correlation between biofilm formation, antibiotic resistance, and biofilm-related risk factors. A total of 207 non-replicate multi-drug-resistant A. baumannii strains were prospectively isolated. Phenotypic identification and antimicrobial susceptibility testing were carried out. Isolate biofilm formation ability was evaluated using the tissue culture plate (TCP), Congo red agar, and tube methods. Clonal relatedness between the strains was assessed by enterobacterial repetitive intergenic consensus-PCR genotyping. Of the 207 isolates, 52.5% originated from an intensive care unit setting, and pan resistance was observed against ceftazidime and cefepime, with elevated resistance (99–94%) to piperacillin/tazobactam, imipenem, levofloxacin, and ciprofloxacin. alongside high susceptibility to tigecycline (97.8%). The Tissue culture plate, Tube method, and Congo red agar methods revealed that 53.6%, 20.8%, and 2.7% of the strains were strong biofilm producers, respectively, while a significant correlation was observed between biofilm formation and device-originating respiratory isolates (p = 0.0009) and between biofilm formation in colonized vs. true infection isolates (p = 0.0001). No correlation was detected between antibiotic resistance and biofilm formation capacity, and the majority of isolates were clonally unrelated. These findings highlight the urgent need for implementing strict infection control measures in clinical settings.

Biofilm Formation and Methicillin Resistance of Staphylococcus aureus Isolated from Clinical Samples

Background: Staphylococcus aureus including methicillin resistant S. aureus (MRSA) is one of the most effective biofilm-forming organisms, biofilm contribute in protecting the microorganism from host defenses and prevent the effective penetration of antimicrobial agents. Biofilm formation is considered as an important contributing factor for the initiation and establishment of chronic infection by S. aureus and known as a major obstacle in the treatment of S. aureus infections is their ability to develop resistance to antimicrobials.
 Aims : To screen clinical Staphylococcus aureus including MRSA isolates for their biofilm forming abilities and their association with antimicrobial resistance.
 Methods: A total of 196 clinical isolates of S. aureus were obtained from different sample sources using standard microbiological techniques from three major hospitals in Gaza strip. Biofilm formation of these isolates was determined by tissue culture plate (TCP) method and tube adherence method (TM). Antimicrobial susceptibility test was performed using the modified Kirby–Bauer disk diffusion method as per Clinical and Laboratory Standards Institute guidelines. MRSA was detected using the cefoxitin disk test.
 Results: Biofilm formation was observed in 174 (88.8 %) and in 145 (74.0%) isolates of S. aureus via TCP method and TM, respectively. The highest resistance percent was for penicillin (92.9%), followed by cefoxitin (80.6%) and oxacillin (67.9%), while the lowest resistance percent was for linezolid and ceftaroline (1%). Among the 196 isolates 71.4% (N=140) were classified as MDR with a MAR index (≥ 0.2).
 A total of 158 isolates (80.6%) were identified as MRSA distributed as 90.4%, 79.4% and 70.9% from Al-Shifa, Al-Nasser pediatrics and Al-Aqsa hospitals respectively. Large proportions (82.1%) of biofilm producers were identified as MRSA. Biofilm-producing MRSA exhibited a higher percent (90.5%) when compared with the biofilm non-producer MRSA (9.5%). Importantly, 89.2% of biofilm-producing S. aureus were multidrug resistant.
 Conclusions: S. aureus isolates possessed high biofilm-forming ability. Biofilm-producing strains have very high tendency to exhibit antimicrobial resistance, multidrug resistance and methicillin resistance. Regular surveillance of biofilm formation by S. aureus and their antimicrobial resistance profile may lead more success in treating S. aureus infections.
 
 Keywords: Biofilm, MDR, MRSA, TCP, TM, Gaza strip, Palestine.

Detection of Biofilm Production and Its Impact on Antibiotic Resistance Profile of Bacterial Isolates from Chronic Wound Infections.

Background:Microorganisms are known to be involved in the formation of biofilm. These biofilms are often seen in chronic wound infections, surgical site infections, implants etc., These are capable of causing recalcitrant infections and most of them are also known to possess high antibiotic resistance.Objectives:This study was conducted to detect the biofilm formation in bacterial isolates from chronic wound infections.Materials and Methods:In the present study, ninety two isolates from chronic wound infections were identified by MALDI-TOF-MS (bioMerieux) and VITEK-2-MS (bioMerieux). These isolates were further screened for biofilm formation by three methods i. e., Tissue Culture Plate method (TCP), Tube Method (TM) and Congo Red Agar (CRA) method. Impact of biofilm production was correlated with the antibiotic resistant pattern.Statistical Analysis:Statistical analysis was done for all three methods considering TCP as Gold Standard and parameters like senitivity and specificity of TM i.e. 47.2 and 100% respectively.Results:Out of 92 isolates, biofilm formation was seen in 72 isolates (78.2%) by TCP method. 64 isolates were strong biofilm producers, 8 isolates were moderate biofilm producers and 20 isolates were nonbiofilm producing. High prevalence of biofilm formation was seen in nonhealing ulcers infected with Staphylococcus aureus followed by Klebsiella pneumoniae.Conclusion:Among three screening methods used for detection of biofilm production, TCP method is considered to be a standard and most reliable for screening of biofilm formation in comparison to TM and CRA.

Occurrence and biofilm forming ability of Pseudomonas aeruginosa in the water output of dental unit waterlines in a dental center in Alexandria, Egypt.

Dental unit waterlines (DUWLs) are notorious for being contaminated with different bacterial species including the opportunistic pathogen Pseudomonas aeruginosa which poses a risk to patients and professionals. This work aimed at studying the occurrence and biofilm-forming ability (BFA) of P. aeruginosa in the output of DUWLs in a dental center in Egypt. Water samples were collected from the outlets of the high-speed hand piece, the air/water syringe and the cup filler waterlines. Bacteriological analysis included heterotrophic plate count (HPC), isolation and identification of P. aeruginosa and determination of the antimicrobial susceptibility and the BFA of the isolates by tissue culture plate (TCP) method and tube method (TM). The average concentration of HPC bacteria in the output of the 3 DUWLs was 2.9×104 CFU/μL where 88.3% of the samples exceeded the Egyptian standards for drinking water (<50 CFU L). P. aeruginosa was isolated from nine cup filler samples (which had a water source different from the other waterlines). The isolates were sensitive to all tested antimicrobials. Of these nine isolates, 6, 5 and 4 were positive for BFA by TCP, modified TCP and TM, respectively. More stringent measures are required to ensure safer dental water; as the majority of studied samples exceeded the required HPC bacterial limit and P. aeruginosa isolates were detected. P. aeruginosa isolates from DUWLs may not be as resistant to antibiotics as what is reported in the literature about clinical isolates. Some P. aeruginosa isolates can colonize DUWLs despite their inability to form biofilms in experimental testing.

Antibacterial activity of Salvadora persica against oral pathogenic bacterial isolates.

The objective was to determine the antibacterial activity of Salvadora persica extract against bacteria isolated from dental plaque of patients. Out of 40 different clinical specimens collected from patients suffering from plaque-induced gingivitis, 12 Staphylococcus aureus and 8 Streptococcus sp. isolates were recovered. The isolates were screened for their biofilm-forming capacity using tissue culture plate (TCP), tube method (TM), and congo red agar (CRA) method. Antibacterial activity of methanolic S. persica extract as well as of commercial antimicrobials against tested isolates was performed. High-performance liquid chromatography-mass spectrometry (HPLC-MS) and gas chromatography-MS (GC-MS) analysis were performed for S. persica crude extract and its volatile oil, respectively, to determine their constituents. Out of 20 isolates, 80%, 85%, and 90% showed positive results using TM, CRA, and TCP, respectively. The highest antimicrobial activity of methanolic S. persica extract was observed at 200 mg/ml. HPLC-MS analysis shows many polyphenols in S. persica extract such as Chrysin-8-c-β-D-glucopyranoside, ferulic acid, gallic acid, and stigmasterol. Chemical composition of the essential oil of S. persica was determined by GC-MS yield; a mixture of monoterpene and hydrocarbons. The major compounds were butylated hydroxytoluene followed by benzene (isothiocyanatomethyl). Methanolic extract of S. persica had significant antibacterial effect against S. aureus and Streptococcus sp. isolates, and it may be gave a good alternative method for controlling oral pathogen.

Tube method and Congo red agar versus tissue culture plate method for detection of biofilm production by uropathogens isolated from midstream urine: Which one could be better?

Background: Bacteria tend to live in assemblies called biofilms that aid bacterial virulence. Biofilms contribute to the development of antibiotic resistant urinary tract infection. Therefore, detection of biofilm production by urinary pathogens can assist the physicians to initiate the proper antimicrobial treatment.Methods: We conducted a prospective study that included patients with suspected urinary tract infection. Collected midstream urine samples were processed by standard microbiological techniques. Detection of biofilm production by the isolated uropathogens was conducted by tissue culture plate method (TCPM), tube method (TM) and Congo red agar (CRA).Results: A total of 43 (29.7%) isolated uropathogens showed positive biofilm formation by TCPM which was considered the gold standard for biofilm detection. When compared with the TCPM, TM truly identified 40 biofilm producers and 83 non-biofilm producers showing sensitivity and specificity of 93.0% and 81.4% respectively. The CRA truly identified 38 biofilm producers and 77 non-biofilm producers with sensitivity and specificity of 88.4% and 75.5% respectively.Conclusion: The TM was superior to CRA in biofilm detection and demonstrated better sensitivity and specificity results. Out of the investigated three phenotypic biofilm detection methods, the TCPM was the ideal method for detection of biofilm formation by uropathogens isolated from midstream urine samples. It can be used routinely in the microbiology laboratory with good specificity results and less subjectivity errors.

Detection of Biofilm Producing Staphylococci among Different Clinical Isolates and Its Relation to Methicillin Susceptibility.

AIMS:To evaluate three in vitro phenotypic methods; tissue culture plate, tube method, and Congo red agar for detection of biofilm formation in staphylococci and assess the relation of biofilm formation with methicillin resistance and anti-microbial resistance.METHODS:The study included 150 staphylococcal isolates. Biofilm detection in staphylococci was performed using tissue culture plate, tube method, and Congo red agar.RESULTS:Tissue culture plate, tube method, and Congo red agar detected 74%, 42.7%, and 1.3% biofilm producing staphylococci respectively. S. aureus isolates were more common biofilm producers (53.2%) than CONS (46.8%). Biofilm production in CONS species was highest in S. hemolyticus (57.7%). Tube method was 51.4% sensitive, 82.1% specific. As for Congo red agar, sensitivity was very low (0.9%), but specificity was 97.4%. Biofilm producers were mostly; isolated from blood specimens and detected in methicillin-resistant strains 96/111 (86.5%). They were resistant to most antibiotics except vancomycin and linezolid.CONCLUSIONS:Tissue culture plate is a more quantitative and reliable method for detection of biofilm producing staphylococci compared to tube method and Congo red agar. Hence, it can still be used as a screening method for biofilm detection. Vancomycin and Linezolid are the most sensitive antibiotics among biofilm producing staphylococci.

In vitro biofilm formation by Staphylococcus aureus isolated from wounds of hospital-admitted patients and their association with antimicrobial resistance.

IntroductionStaphylococcus aureus including methicillin-resistant S. aureus (MRSA) has the propensity to form biofilms, and causes significant mortality and morbidity in the patients with wounds. Our aim was to study the in vitro biofilm-forming ability of S. aureus isolated from wounds of hospitalized patients and their association with antimicrobial resistance.Materials and methodsForty-three clinical isolates of S. aureus were obtained from 150 pus samples using standard microbiological techniques. Biofilm formation in these isolates was detected by tissue culture plate (TCP) method and tube adherence method (TM). Antimicrobial susceptibility test was performed using the modified Kirby–Bauer disk diffusion method as per Clinical and Laboratory Standards Institute guidelines. MRSA was detected using the cefoxitin disk test.ResultsBiofilm formation was observed in 30 (69.8%) and 28 (65.1%) isolates of S. aureus via TCP method and TM, respectively. Biofilm-producing S. aureus exhibited a higher incidence of antimicrobial resistance when compared with the biofilm nonproducers (P<0.05). Importantly, 86.7% of biofilm-producing S. aureus were multidrug resistant (MDR), whereas all the biofilm nonproducers were non-MDR (P<0.05). Large proportions (43.3%) of biofilm producers were identified as MRSA; however, none of the biofilm nonproducers were found to be MRSA (P<0.05).ConclusionBoth the in vitro methods showed that S. aureus isolated from wound infection of hospitalized patients have high degree of biofilm-forming ability. Biofilm-producing strains have very high tendency to exhibit antimicrobial resistance, multidrug resistance and methicillin resistance. Regular surveillance of biofilm formation by S. aureus and their antimicrobial resistance profile may lead to the early treatment of the wound infection.

Effect of storage tube material and resveratrol during liquid storage of matured bovine oocytes on subsequent development.

This study determined the optimum storage vessel and the effects of resveratrol for the storage of in vitro matured (IVM) bovine oocytes. After IVM, the oocytes were kept in a Hepes-buffered medium at 25 °C for 20 h in different containers including Eppendorf tubes (ET) made of polypropylene (PP) and polystyrene (PS), and tissue culture tubes (TCT) made of PP, PS, and glass. Then oocytes were subjected to IVF and subsequent in vitro embryo development was compared among the groups and to that of a control group without storage. The percentage of blastocyst development in the control group was significantly higher than in the stored groups (P < 0.05). Among oocytes stored in TCT, the percentage of blastocyst development of oocytes stored in glass TCT was significantly higher than that of oocytes stored in PP and PS TCT (P < 0.05); however, it did not differ from that of oocytes stored in ET. The quality of blastocysts did not differ among the control and stored groups. Embryo development was not affected when 0.1, 1 or 10 μM resveratrol was added to the medium during oocyte storage. In conclusion, glass tubes were optimal for oocyte storage and resveratrol did not improve the development of stored oocytes.

Role of Biofilm in Cerebrospinal Fluid Shunt Infections: A Study at Tertiary Neurocare Center from South India.

Introduction:Biofilms are the source of persistent infections of many pathogenic microbes. They are responsible for nosocomial infection and also associated with many surgical conditions including indwelling medical devices such as ventriculoperitoneal shunt. A significant problem encountered in shunt procedures is obstruction followed by infection, with infection rate ranging from 2% to 27%, often with poor outcome.Materials and Methods:This study was conducted in the Department of Neuromicrobiology at a tertiary neuroinstitute for 6 months from July 1 to December 31, 2014. The samples comprised cerebrospinal fluid (CSF) from suspected cases of shunt infections. Laboratory diagnosis of causative agent was established by adopting standard procedures. Then, isolates were evaluated for production of biofilm by tissue culture plate (TCP) method and tube method.Results:Of the 1642 shunt CSF samples obtained from neurosurgery, 14.79% were culture positive which yielded 254 isolates. About 51.97% were Gram-negative bacilli (GNB), 46.46% were Gram-positive cocci (GPC), and 1.57% were Candida albicans. Among GNB, nonfermenters were the most common (51.52%) followed by Pseudomonas aeruginosa (15.9%). Among GPC, coagulase-negative Staphylococci were 88.13%, out of which 43.26% were methicillin-resistant. Other GPC were Enterococcus spp. (4.24%), Staphylococcus aureus (5.08%), and Streptococcus spp. (2.54%). Among all isolates, 120 were tested for biofilm production, out of which 57.5% were biofilm producers and 42.5% were nonproducers.Conclusions:TCP was the better method to detect biofilm. Most of the biofilm producers were resistant pathogens.

Comparison of MIC with MBEC Assay for &amp;lt;i&amp;gt;in Vitro&amp;lt;/i&amp;gt; Antimicrobial Susceptibility Testing in Biofilm Forming Clinical Bacterial Isolates

Context: MIC results can be misleading for treatment of biofilm associated. The Minimum Biofilm Eradication Concentration (MBEC) measures the determination to be made for a biofilm susceptibility to antibiotics. Aims: Assessment of biofilm production and comparison of the MIC and MBEC assays evaluate differences in the antibiotic sensitivity patterns of different clinical bacterial isolates from patients implanted with medical devices. Settings and Design: Random sampling with experimental study at tertiary care institute. Methods and Material: The study was carried out during January 2014 to March 2014 on 50 positive bacteriological cultures of medical devices which were inserted in hospitalized patients. Biofilm forming strains were identified by tissue culture plate method & tube method. Biofilm-producing and non-biofilm forming reference strains were used as controls. Assay has been developed for the use with flat bottom, 96-well microtiter plates. Sterile autoclaved PCR tubes were used as pegs which provided surface for the biofilm formation. Amikacin, ciprofloxacin, trimethoprim-sulfamethoxazole, vancomycin, cefoperazone/ sulbactam, gentamycin were tested for MIC and MBEC assay. Statistical Analysis Used: Results will be discussed in the form of percentages. Results: Colonization by Klebsiella pneumoniae, Acinetobacter baumanni and Pseudomonas aeruginosa was prevalent bacterial isolates in medical devices. MBEC was higher for all the antibiotics as compared to MIC except amikacin MBEC for Pseudomonas was the same as MIC. Conclusions: Device associated bacterial biofilms are the major source of infections in patients of critical care setup. MIC misleads physician for organism’s drug susceptibility testing, which results in therapeutic failure. MBEC can guide regarding choice and proper dosing of antibiotics to be given. That’s why major studies for similar testing should be done with clinical evaluation.

Detection of biofilm production in blood culture isolates ofStaphylococci

Background: Biofilm producing bacteria which are inherently resistant to antibiotics and disinfectants are widely associated with implant associated infections. Staphylococcus is the most commonly associated pathogens with bloodstream infection. Aims: The current study was conducted to detect biofilm production in Staphylococci isolated from blood culture specimens. Materials and Methods: 70 clinically significant staphylococcal isolates from blood culture were screened for biofilm production by Tissue culture plate (TCP) method, Tube method (TM) and Congo red agar (CRA) method and their antibiotic susceptibility profile was studied. Results: 59 out of 70 staphylococcal isolates were positive by TCP, out of these 21.4% staphylococci were high biofilm producers, 62.8% staphylococci were moderate biofilm producers and 15.8% were non-biofilm producers. Maximum resistance was observed in biofilm producers to cotrimoxazole (74.5%) and erythromycin (62.7%) and none were resistant to vancomycin and linezolid. Out of total 59 biofilm producers, 20.3 % (12) were methicillin resistant and all these were S. aureus isolates. 19% (1) out of total 11 biofilm non-producers were methicillin resistant. Conclusion: Biofilm production was seen to be a major virulence factor in most of the staphylococcal isolates obtained from patients with signs and symptoms of septicaemia. S. aureus was found to be the major pathogen and timely detection of biofilm producing phenotype should be carried out using a simple and reproducible method, TCP which is both qualitative and quantitative.