National Committee For Clinical Laboratory Standards Research Articles

Susceptibility of Candida albicans, Staphylococcus aureus and Escherichia coli to Extracts of Mango (Magnifera indica)

Aim: This study was carried out to investigate the Susceptibility of Candida albicans, Staphylococcus aureus and Escherichia coli to extracts from young and mature mango (Magnifera indica) leaves and stem-bark of the same plant. 
 Study Design: The study employed statistical analysis of the data and interpretation. 
 Place and Duration of Study: Young and mature mango leaves and stem-barks were collected from the Botanical Garden, Kenule Beeson Saro-Wiwa Polytechnic, Bori, Nigeria, and taken to the laboratory for analyses. 
 Methodology: The samples were dried in an oven at 80oC for 3 days. Thereafter, 50 g of each ground mango leaves and stem-bark (young and mature of the same plant) were soaked separately in 500 ml of water, ethanol (95% v/v), and acetic acid (99.9% v/v) for another 3 days. The soaked materials were filtered through Whatman No. 1 filter paper into sterile beakers and evaporated to dryness in a water-bath at 80oC. The dried extracts obtained were reconstituted with water at concentrations of 100, 75, 50 and 25 mg/ml. Test organisms, Candida albicans, Staphylococcus aureus and Escherichia coli were obtained after proper laboratory screening of isolates from the diagnostic laboratory of the Rivers State University Teaching Hospital, Port Harcourt, Nigeria, for confirmation of identity and storage in universal bottles in a refrigerator. Sensitivity tests were carried out with the agar well diffusion method against the test organisms, using tetracycline as standard control drug (for bacteria) and fluconazole (for Candida), with cultures incubated accordingly. The measured zones of inhibition were compared with the controls and interpreted as resistant, intermediate, or susceptible to mango extracts in accordance with the interpretive guidelines published by the National Committee for Clinical Laboratory Standards (NCCLS). Assays for minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were also carried out.
 Results: Results obtained showed that Escherichia coli was completely susceptible to acetic acid young leaf and young bark extracts at 100 mg/ml concentrations. Staphylococcus aureus was susceptible only to Acetic acid young leaf extract at 100 mg/ml. For Candida albicans complete susceptibility was with acetic acid young bark at 100 mg/ml. mature leaf extract (100 mg/ml ), acetic acid young bark extract (100 to 50 mg/ml ), aqueous young bark extract (100 mg/ml) and acetic acid mature Candida albicans was susceptible to acetic acid young and mature bark extract at 100 mg/ml concentration. Minimum inhibitory concentration (MIC) values of acetic acid young leaf extract for all three organisms were 12.5 mg/ml. MIC of ethanolic young leaf extract for E. coli was 12.5 mg/ml whereas that for C. albicans was 50 mg/ml. Minimum bacteriocidal concentration values were same as MIC.
 Conclusion: E. coli and S.aureus were found to be most susceptible to acetic acid young leaf and stem-bark mango extracts. For C. albicans susceptibility profiles were best with aceti acid young and mature stem-bark extracts. It was also found that mango phytochemicals have broad-spectrum antibacterial activity as well as antifungal properties. The study also reveals that young mango parts contain higher bioactive substances than mature parts. Finally, it was concluded that acetic acid extracts produced the highest antimicrobial effects whereas aqueous extracts produced the least.

English

Essential oil compounds of Croton pseudopulchellus and Croton gratissimus were analysed using Gas Chromatography/Mass Spectrophotometry and screened for antimicrobial activity against Bacillus pimilus (ATCC 29212), Bacillus cereus (ATCC 10702), Staphylococcus aureus (ATCC 3983), Streptococcus faecalis (ATCC 29212), Escherichia coli (ATCC 4983), Klebsiella pneumoniae (ATCC 2983) and Pseudomonas aeruginosa (ATCC 19582) using Agar gel disk diffusion test and minimum inhibitory concentrations. The susceptibilities of all isolates of different essential oil compounds were standardised by National Committee for Clinical Laboratory Standards (NCCLS) 1998). The cytotoxicity test was also carried out to determine the toxicity levels of essential oil compounds. These plants were selected based on their use by traditional healers for treatment of upper respiratory tract, gastrointestinal tract and urinary tract infections. The essential oil compounds of C. pseudopulchellus and C. gratissimus were found to be active against all the test microorganisms, while the preliminary assessment of essential oil compounds from these plants exhibited low cytotoxic activity.   Key words: Essential oil, sesquiterpenes, chemical composition, antimicrobial activity.

Leaf extract of Strychnos ligustrina Blume inhibited Propionibacterium acnes growth in vitro

Propionibacterium acnes plays an important role in inducing skin inflammatory mediators and comedogenic acne. This study aimed to evaluate the antimicrobial effect of Strychnos ligustrina Blume leaf extract against P. acnes. This study was an in-vitro experiment with a completely randomized design (CRD) testing five concentrations of ethanolic extract of S. ligustrina leaves. The control treatment was the antibiotic Kindamicin. The anti-bacterial evaluation of the extract was carried out on Mueller-Hinton agar media by using the diffusion method. The inhibition zone was assessed according to NCCLS (National Committee for Clinical Laboratory Standards). Analysis and interpretation of the results used 95% ANOVA (α: 0.05). The results of the study showed that S. ligustrina leaf extract inhibited the bacterial growth of P. acnes. The minimum concentration of the extract that inhibited the growth of P. acne was 25% with a diameter inhibition zone of 4.13 ± 0.13 mm, while the highest concentration of the undiluted extract was 7.88 ± 0.67 mm. Compared to the standard antibiotic Kindamycin (positive control), the ethanolic leaf extract of S. ligustrina was less effective having an inhibition zone of 24.81 ± 0.54 mm. The study suggests that S. ligustrina leaf extract has antimicrobial effects on P. acnes and may be further studied as an herbal remedy for acne.

Interest of water quality in Clinical laboratory experience of the central laboratory of Mohammed VI University Hospital of Oujda

Water is the most used reagent in clinical laboratories. It is used for all levels of chemical, biological and physical analysis. It is important to know the type of water used because many analyses can be affected by its quality. Several agencies have established preparation and purity criteria for water.The objective of our work is to highlight the interest of water quality in the laboratory by presenting the experience of the Central Laboratory of Mohammed VI University Hospital of Oujda.Classically, water was classified according to a 3-tier system (Type I, II and III) by the National Committee for Clinical Laboratory Standards (NCCLS) which has been replaced by a more specific system developed by the Clinical and Laboratory Standards Institute (CLSI) guidelines that recommend the use of pure water for optimal laboratory testing. Clinical Laboratory Reagent Water (CLRW) is defined as the minimum quality water appropriate for routine biochemical testing.Poor water quality can have a great influence on the preparation of culture media, the preparation of reagents and dyes, the reconstitution of lyophilized material, dilution techniques are procedures that can be affected by laboratory water and may greatly influence the results obtained.Different techniques are used for water treatment such as filtration, distillation, reverse osmosis, ultraviolet photo-oxidation, deionization and many others.The water used in our laboratory is ultrapure, it contains only H20, as well as a balanced number of H + and OH– ions. It has a resistivity of 18.2 MΩ.cm, a TOC < 10 ppb, and a bacterial count < 10 CFU/ml.In order to guarantee this best quality, we use a unique system integrating five water treatment technologies. This will constitute a solid basis to guarantee the reliability of the results of the examinations according to the NF EN ISO 15,189 standard, a laboratory accreditation procedure in which we are engaged.

Antibacterial Properties of Young and Mature Mango Leaves (Mangifera indica) Extract on Some Clinical Isolates

Aim: This study was carried out to investigate the antibacterial properties and efficacy of mango (Mangifera indica) leaf extracts on some clinical isolates as test rganisms. &#x0D; Study Design: The study employed statistical analysis of the data and interpretation&#x0D; Place and Duration of Study: Young and mature mango leaves were collected from the Botanical Garden, Kenule Beeson Saro-Wiwa Polytechnic, Bori, Nigeria, and taken to the laboratory for analyses. &#x0D; Methodology: The samples were dried in an oven at 80oC for 3 days. Thereafter, 50 g of each ground mango leaf (young and mature leaves) were soaked separately in 500 ml of water, ethanol (95% v/v), and acetic acid (99.9% v/v) respectively for another 3 days. The soaked materials were filtered through Whatman No. 1 filter paper into sterile beakers and evaporated to dryness in a water bath at 80oC. The dried extracts obtained were reconstituted with water at concentrations of 100, 75, 50, and 25 mg/ml. Test organisms, Escherichia coli, Staphylococcus aureus, Salmonella typhi, Proteus mirabilis, Bacillus cereus, and Pseudomonas aeruginosa were obtained after proper laboratory screening of isolates from the diagnostic laboratory of the Rivers State University Teaching Hospital, Port Harcourt, Nigeria, for confirmation of identity and storage in universal bottles in a refrigerator. Sensitivity tests were carried out with the agar well diffusion method against the test organisms, using tetracycline as the standard control drug, with cultures incubated accordingly. The measured zones of inhibition were compared with the controls and interpreted as resistant, intermediate, or susceptible to mango extracts in accordance with the interpretive guidelines published by the National Committee for Clinical Laboratory Standards (NCCLS). Assay for minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was also carried out.&#x0D; Results: Results obtained showed that acetic acid young leaf extract at 100mg/ml produced 50 % susceptibility and 50 % intermediate response of test bacterial species. Generally, at 100 mg/ml, acetic acid young leaf extracts yielded 50% susceptibility and 50% intermediate response among both Gram-positive and Gram-negative bacteria. Ethanolic extracts gave 100% intermediate sensitivity of Gram-negative species and 50% each of resistant and intermediate response in Gram-positive forms. Aqueous extracts also produced no susceptibility among the test organisms as there was 100% resistance. Extracts of mature mango leaves of all solvents and at all concentrations used yielded no susceptibility response among the test bacterial species on the NCCLS scale. Minimum inhibitory and bactericidal concentrations were found to range from 25 mg/ml to 50 mg/ml. Additionally, it was observed that the sensitivity of organisms to mango extracts increased with concentration.&#x0D; Conclusion: In conclusion, acetic acid has a better extracting potential than ethanol and water as a solvent for the extraction of mango parts. More so, young mango leaves extracted with acetic acid possess higher broad-spectrum antibacterial properties than the mature mango leaves extracted from the same plant. It is therefore recommended that young mango leaves, extracted with acetic acid, be used for the treatment of microbial infections at concentrations not below 50 mg/ml.

Positive Pattern of Antibiotic Sensitivity in Blood Cultures Disease Caused by a Typhoid

Objective: The purpose of this study establish the antibiotic sensitivity pattern in blood culture positive typhoid illness. Study Design: Retrospective study Place and Duration: Mayo Hospital Lahore. April 2021-Dec 2021 Methods: There were a total of 98 male and female patients. Patients ranged in age from 8 to 60. After obtaining informed written permission, we collected demographic data on each patient, including age, gender, and BMI. All of the patients were suffering from a fever. All patients had their blood tested for the presence of salmonella species. Antibiotic susceptibility was determined using the Kirby Bauer Disc Diffusion technique and interpreted in compliance with National Committee for Clinical Laboratory Standards (NCCLS) standards. SPSS 24.0 was used to analyse all of the data in the study. Results: Among 98 patients, 61(62.2%) were males and 37 (37.8%) females. Majority of the patients 38 (38.8%) were from age group 21-30 years. Frequency of typhi 69 (70.4%) was greater than that of paratyphi 29 (29.6%). According to our research findings, Azithromycin, chloramphernicol, cotrimoxazole, genramycin, and azithromycin all had better sensitivity than ciprofloxacin and ofloxacin (10.2%, vs 7.1%) . However, both medications have a significant level of resistance. Salmonella typhi was resistant to 91(92.9 %) of the nalidixic acid tested. Conclusion: We found a wide range of antimicrobial sensitivity patterns, including exceptionally high sensitivity to antibiotics like chloramphenicol and cotrimoxazole that have been used in the past. Quinolones, which have been extensively used in the previous two decades, have been shown to have an extremely low sensitivity. Keywords: Resistance, Sensitivity ,Typhoid fever, Antibiotics

Antibiotic Sensitivity Pattern in Blood Culture Positive Typhoid Fever

Objective: The aim of this study is to determine the antibiotic sensitivity pattern in blood culture positive typhoid fever. Study Design:Retrospective study Place and Duration:Children Medical Center (CMC) / Dr Habib un Nabi Children Hospital Mingora Swat and Pediatrics department of Hamdard University Hospital, Karachi for the duration between June 2020 and December 2020. Methods: There were total one hundred and twenty patients of both genders were presented. Patients were aged between 5-15 years of age. Patients detailed demographics age, sex and body mass index were recorded after taking informed written consent. All the patients had fever. Blood sample of all the patients were taken for salmonella species. The Kirby Bauer Disc Diffusion method was used to test for antibiotic susceptibility, and the results were interpreted in accordance with National Committee for Clinical Laboratory Standards (NCCLS) guidelines. SPSS 20.0 version was used to analyze complete data. Results:There were 84 (70%) males and 36 (30%) females. Mean age of the patients was 11.5±3.48 years. Among 120 cases of salmonella, 89 (74.2%) were Salmonellatyphi and Salmonella paratyphi was found in 31 (25.8%) patients. Sensitivity of antibiotics chloramphericol, cotrimoxazole, and azithromycin was 100% greater than that of ciprofloxacin and ofloxacin. (6.7%, vs 5.8%) But resistance of both antibiotics was high. Nalidixic Acid showed 108 (90%) resistance to salmonella typhi. Conclusion: We observed a very high degree of diversity in the antimicrobial sensitivity pattern, with extremely high levels of sensitivity to antibiotics that have been utilized in the past, such as chloramphenicol and cotrimoxazole. It was discovered that the quinolones, which were widely utilized in the last two decades, have a very poor sensitivity. Keywords:Typhoid fever, Sensitivity, Antibiotics, Resistance

Substituted Imidazole-Pyrazole Clubbed Scaffolds: Microwave Assisted Synthesis and Examined Their In-vitro Antimicrobial and Antituberculosis Effects

A series of substituted imidazole-pyrazole fused compounds were designed &amp; fused synthesized by employing Debus-Radziszewski one-pot synthesis reaction. Azoles are an extensive and comparatively new class of synthetic compounds including imidazoles and pyrazoles. The current clinical treatment uses compounds of azole framework. Azoles act by inhibiting ergosterol synthesis pathway (a principal component of the fungal cell wall). In addition, a literature review shows that the compounds that include imidazoles and pyrazoles have significant anti-bacterial and anti-mycobacterial effects. In light of the above findings, a series of compounds with imidazole and pyrazole scaffolds were sketched and developed to examine anti-bacterial, antifungal and antimycobacterial activities. The structures of the synthesized compounds were characterized using &lt;sup&gt;1&lt;/sup&gt;HNMR, &lt;sup&gt;13&lt;/sup&gt;CNMR, elemental analysis, and MS spectral data. The target compounds were screened for their in-vitro antimicrobial activity against gram-positive and gram-negative bacterial species by disc diffusion method according to the NCCLS (National Committee for Clinical Laboratory Standards) and anti-mycobacterial activity against the Mycobacterium tuberculosis H37Rv strain. The results revealed that imidazole-pyrazole fused scaffold compounds have potential antibacterial, antifungal and anti-mycobacterial activities which can be further optimized to get a lead compound.

Antibiotic Resistance Pattern of Propionibacterium acnes Isolated from Patients with Acne Vulgaris at the Dermatology Clinics of Kasr Al-Ainy Teaching Hospital Egypt

Background: Propionibacterium acnes (P. acnes) has been implicated in the pathogenesis of acne vulgaris since the beginning of the last century. Over several decades, topical and systemic antibiotics have been the main line of treatment for acne vulgaris. However, in the present era of increased antibiotic usage, resistant strains have emerged. Objectives: The aim of this study is to determine the antibiotic resistance pattern of P. acnes isolated from patients with acne vulgaris at the dermatology clinics of Kasr Al-Ainy teaching Hospital. Methodology: Specimens from 100 patients with acne vulgaris were extracted from the pustules, taken by sterile cotton swabs and transported by thioglycolate media. Each swab was inoculated onto two blood agar plates, one incubated aerobically at 37ºC for 24h and the other anaerobically for one week. P. acnes was identified by Gram stain and biochemical tests. Their sensitivity to doxycycline, erythromycin, clindamycin, tetracycline, azithromycin and trimethoprimsulfamethoxazole was determined on Muller Hinton media by disc diffusion method. Results were interpreted according to the National Committee for Clinical Laboratory Standards (NCCLS) guidelines. Results: A total of 44 P. acnes isolates were identified from 100 patients with acne vulgaris, out of which 22.7% were resistant to clindamycin, 11.4% were resistant to trimethoprim-sulfamethoxazole and 9% were resistant to erythromycin. Resistance to doxycycline, tetracycline or azithromycin was not detected. Trimethoprim-sulfamethoxazole showed statistically significant difference in the resistance pattern compared to patient’s sex (p = 0.029) and to receiving previous treatment (p = 0.018). Conclusion: P. acnes is prevalent in patients with acne vulgaris (44%) and resistant strains are detected especially in those who have received previous therapy for more than 2 weeks (68%). It is recommended that dermatologists and family physicians follow the guidelines for proper management of acne, with the judicious use of antibiotics, in order to prevent antibiotic resistance.

To study the profile of Candida isolates and antifungal susceptibility pattern of neonatal sepsis in a tertiary care hospital of North India

Aims and objective To study the profile of Candida infection and antifungal susceptibility (AFS) pattern in neonatal sepsis. Materials and methods In this prospective observational study, 850 blood samples were collected and processed from neonates who were suspected clinically to have sepsis. The blood culture that showed growth of Candida was further processed for species identification. Antifungal susceptibility was done as per the National Committee for Clinical Laboratory Standards (NCCLS)/Clinical Laboratory Standards Institute (CLSI) M44-A-2 guidelines by disc diffusion method and automated vitek-2 compact system. Candidemia was diagnosed by isolation of Candida species from at least one positive blood culture containing pure growth of Candida species with supportive clinical features. Results Candida species were isolated in 32 specimens of the total 322 culture-positive cases. The most common isolate was Candida tropicalis (14/32; 43.75%) followed by Candida albicans (7/32; 21.87%) and Candida glabrata (6/32; 18.75%). The three most common neonatal risk factors for candidemia were low birth weight, prolonged use of intravenous antibiotics and presence of central venous line. Non-albicans Candida (NAC) showed good sensitivity to fluconazole as compared to Candida albicans. The fluconazole sensitivity of Candida tropicalis, Candida glabrata, and Candida parapsilosis was 93, 67, and 100%, respectively, whereas it was 57% in Candida albicans. The sensitivity to amphotericin B was 95% among all Candida isolates. All NAC were sensitive to amphotericin B, while only 72% Candida albicans were sensitive to amphotericin B. Conclusions The incidence of neonatal sepsis secondary to NAC is increasing and has replaced Candida albicans as a major cause of neonatal fungal sepsis. Low birth weight is the most important risk factor for Candida sepsis. The resistance of Candida albicans is increasing for both fluconazole and amphotericin B when compared to NAC. Increasing antifungal resistance warrants its judicious use both for prophylaxis and treatment.

Antibacterial activity of essential oil extracts from Curcuma xanthorrhiza roxb. rhizomes against bacteria causing pulp necrosis

Objective: To analyze antibacterial activity of essential oil extracted from Curcuma xanthorrhiza Roxb. rhizomes against bacteria causing pulp necrosis, Enterococcus faecalis, and Fusobacterium nucleatum.Material and Methods: The method used in this research was disc-diffusion on MH-A media, based on the standard protocol of National Committee for Clinical Laboratory Standards (NCCLS). This method used 4 replications in each of the study group. The study group consists of 4 different concentration groups (25%, 50%, 75% and 100% ) of Temulawak rhizomes essential oil extracts, ChKM and Cresophene were used as the positive control group and DMSO (10%) and Tween 80 (0.5%) was used as the negative control group.Results: The inhibition zones of 25%, 50%, 75%, and 100% of temulawak rhizomes essential oil extracts against E. faecalis were 8.17 mm, 8.54 mm, 9.53 mm, and 10.17 mm, respectively. Whereas, the inhibition zones of 25%, 50%, 75%, and 100% of temulawak rhizomes essential oil extracts against F. nucleatum were 8.54 mm, 8.95 mm, 9.65 mm and 10.75 mm, respectively. Data analysis using Kruskal-Wallis in both of bacteria showed p=0.00 (p&lt;0.05) and therefore, significant levels of inhibition.Conclusion: Essential oil extracts from C. xanthorrhiza Roxb. rhizomes has medium antibacterial activity against E. faecalis and F. nucleatum.

Evaluation of antimicrobial resistance pattern of uropathogens in a tertiary care hospital in Dhaka city, Bangladesh

Urinary tract infection (UTI) is one of the most common bacterial infections seen in developing countries like Bangladesh. This study is, therefore, designed to determine the bacterial uropathogens and their antibiotic resistance pattern among patients with complaints of UTIs in Dhaka city. This study was carried out in the laboratory of the Department of Microbiology, Bangladesh Medical College, Dhaka, Bangladesh from January to June 2015. A total of 2541 urine samples were collected in sterile containers from suspected urinary tract infected cases. A specimen was considered positive for UTI if an organism was cultured at a concentration of ≥105CFU/ml or when an organism was cultured at a concentration of 104CFU/ml and &gt;5 pus cells per high power field. Antimicrobial susceptibility testing of the isolated bacterial species was performed by disc diffusion method following the National Committee for Clinical laboratory Standards (NCCLS) guidelines. A total of 303 (11.92%) bacterial uropathogens were isolated from 2541 urine samples. Among the 303 isolates, majority of the isolates 197 (65.02%) were from females. Both the age groups up to 18 years and above 18 years the highest prevalence was found in females 34(11.22%) and 163 (53.79%) respectively. Most predominant organism was Escherichia coli 262(86.46%)followed by Pseudomonas 12(3.96%), Enterococci 12(3.96%), Klebsiella11(3.63%). Escherichiacoli showed very high resistance to amoxycillin 95.41%, cefradin 90.45%, nalidixic acid and Klebsiella to amoxycillin 90.90%, nitrofurantoin 90.90%. Again Pseudomonas was highly resistant to cefuroxime 100%, cefexime 100%and ceftriaxone 83.33%. Enterococci were found highly resistance to cefexime 91.66%, cloxacillin 83.33%, and erythromycin 83.33%.Due to wide scale resistance of the drugs used to treat UTI, choice of drugs in the treatment of UTI is quite narrow. In country like ours awareness for prevention of UTI should be encouraged among the community level as it affects all age groups.South East Asia Journal of Public Health Vol.7(2) 2017: 12-18

Ionic Liquid-Promoted Synthesis of Novel Chromone-Pyrimidine Coupled Derivatives, Antimicrobial Analysis, Enzyme Assay, Docking Study and Toxicity Study.

Herein, we report an environmentally friendly, rapid, and convenient ionic liquid ([Et3NH][HSO4])-promoted facile synthesis of ethyl 4-(6-substituted-4-oxo-4H-chromen-3-yl)-6-methyl-2-thioxo/oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate derivatives 4(a–f) and 4-(6-substituted-4-oxo-4H-chromen-3-yl)-6-methyl-2-thioxo/oxo-1,2,3,4-tetrahydropyrimidine-5- carbohydrazide derivatives 6(a–f). All the synthesized derivatives 4(a–f) and 6(a–f) were evaluated for their in vitro antifungal and antibacterial activity, by method recommended by National Committee for Clinical Laboratory Standards (NCCLS). The compound 6c bearing a fluoro group on the chromone ring and oxygen and a hydrazino group (–NHNH2) on the pyrimidine ring, was found to be the most potent antibacterial compound amongst the synthesized derivatives. The compound 6f bearing a methoxy group (–OCH3) on the chromone ring and sulphur group on the pyrimidine ring, was found to exhibit equipotent antifungal activity when compared with the standard drug miconazole. A d-alanine-d-alanine ligase (DdlB) enzyme assay study and an ergosterol extraction and quantitation assay study were performed to predict the mode of action of the synthesized compounds. A molecular docking study was performed to predict the binding interactions with receptors and mode of action of the synthesized derivatives. Further, analysis of the ADMET parameters for the synthesized compounds has shown that these compounds have good oral drug-like properties and can be developed as oral drug candidates. To establish the antimicrobial selectivity and safety, the most active compounds 6c and 6f were further tested for cytotoxicity against the human cancer cell line HeLa and were found to be non-cytotoxic in nature. An in vivo acute oral toxicity study was also performed for the most active compounds 6c and 6f and the results indicated that the compounds are non-toxic in nature.

Making Sense of Antimicrobial Resistance Surveillance: A successful intervention

Background: The intensive care units are epicenters for the emergence of antibiotic resistant Gram-negative bacteria because of the high use of antibiotics, prolonged hospital stay, reduced patient immunity, use of medical devices, and the frequent contact between healthcare workers and patients. Surveillance of bacterial resistance is the key element to understand the size of the problem, drive interventions, and measures the effect of these measures. Several reports have linked the use of third generation cephalosporins with β-lactam resistance in gram-negative bacteria. Several strategies were introduced by the Antibiotic Stewardship Programs to reduce antibiotic resistance but the efficacies of these interventions are not well studied. Methods: The Microbiology Laboratory of Hamad Medical Corporation (HMC) monitors antimicrobial resistance by continuous surveillance using the National Committee for Clinical Laboratory Standards (NCCLS) - currently Clinical Laboratory Standards Institute interpretive criteria. Surveillance data were released annually and shared with clinicians and policy makers for review of the antibiotic policy and the antibiotic formulary. Results: Surveillance data in 2001 showed high level β-lactam antibiotics resistance and high level production of extended spectrum β-lactamases (ESBL) among gram-negative bacteria. As a result, the Hospital Antibiotic Policy Committee decided to withdraw ceftazidime a third –generation cephalosporin known to be a strong inducer of ESBL, from the hospital formulary. Subsequent resistance surveillance over the following three years in the Medical Intensive Care unit (MICU) demonstrated a gradual drop in the resistance of Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli; the commonest isolated gram negative bacteria from MICU), not only to third and fourth generation cephalosporins, but also to Piperacillin – Tazobactam in spite of the increased use of the later drug in the MICU. Discussion and conclusion: Antibiotic resistance is an increasing global problem. Surveillance studies are needed to monitor resistance development, to guide local empirical therapy, and to implement timely and adequate countermeasures. Since resistance development is an evolutionary process, constant surveillance is necessary to gain insight into the problem in a timely fashion. Several measures were taken including antibiotic cycling, antibiotic rotation and restriction. Restriction of the use of Ceftazidime resulted in a significant drop in the resistance of the common Gram-negative bacteria to the betalactam antibiotics. The sustainability and efficacy of these measures need to be monitored over time.

In vitro effects of glycyrrhetinic acid and hyaluronic acid on the growth of vulvovaginal Candida albicans and other yeasts

Aims. The present study aimed to test the in vitro activity against Candida albicans and non-albicans strains of 18-β glycyrrhetinic acid (18-β GA) and hyaluronic acid (HA), both alone and in combination. This antimicrobial activity was assessed using the National Committee for Clinical Laboratory Standards (NCCLS) method on Candida strains that were isolated from patients with recurrent vulvovaginal candidiasis (RVVC). Results. Our results demonstrate that the anti-Candida activity is independent from antifungal susceptibility level and the fact that the growth inhibition is stronger at acidic pH level makes the two drugs a promising biological alternative for the topical treatment of vulvovaginal candidiasis (VVC) and RVVC. Conclusions. Furthermore, the reduction of both budding cells formation and germ tube elongation, on mammalian cell monolayers, may explain the observed growth inhibition and suggest a decreased virulence, respectively.

In vitro MIC of Itraconazole Against Different Isolates of Candida albicans

In vitro antifungal susceptibility test of itraconazole was carried out against 38 isolates from nails, skin, oral cavity, vagina and wounds, This study was done in Ramadi Teaching Hospital in period from January to August 2010. According to the National Committee for Clinical Laboratory Standard (NCCLS ) M 27- A by using the broth dilution method. Inoculum size was 1-5X103 CFU/ ml, while final concentrations of itraconazole ranged from 0.025 – 6.4 μg / ml by using RPMI – 1640 broth media and the fungus was incubated at 35 oC. No resistant stain was recorded. MIC ranged from 0.05 – 6.4 μg / ml and the Mean ± SEM was 0.89 ± 0.28. MIC for nail isolates was 0.05 – 6.4 μg/ ml, for skin isolates it was 0.05 – 6.4 μg / ml, for oral cavity isolates it was 0.05 – 0.4 μg/ ml, for vagina isolates it was 0.1 – 6.4 μg / ml and for wound isolates it was 0.1 – 1.6 μg/ ml. MIC50 was 0.2 μg / ml and MIC90 was 1.6μg / ml. Itraconazole acts as fungistatic more than fungicidal agent; in 25( 65.8% ) isolates it acts as fungistatic and as fungicidal in 13 (34.2 % ) isolates.&#x0D; Key words: Itraconazole, C. albicans.

SKRINING AKTIVITAS ANTIBAKTERI DAUN KELOR (Moringa oleifera), DAUN BIDARA LAUT (Strychnos ligustrina Blume), DAN AMOXICILIN TERHADAP BAKTERI PATOGEN Staphylococcus aureus

Exploration of a variety of plants as a source of antibacterial has been done, but it is not all plants effective to inhibit the growth of bacteria. This study aims to determine the difference between the ability of the antibacterial activity of plant leaves Moringa oleifera and Strychnos ligustrina Blume against Staphylococcus aureus bacteria growth. This research is an experiment with a completely randomized factorial design (CRD) 3x4 with four replicates. The materials use is ethanol extract of the leaves of Moringa leaf extract, S. ligustrina , and amoxicillin. Testing the antibacterial activity performed on Mueller-Hinton agar media with the diffusion method. The analysis and interpretation of results were done by ANOVA 95% (α: 0.05). Susceptibility bacteria to antibiotics, and plant extracts assessed according to standard NCCLS ( National Committee for Clinical Laboratory Standards ). The antibacterial agent (ethanol extract of Moringa leaf, ethanol extract of S. ligustrina leaf, and amoxicillin) and concentrations influence significantly inhibit the growth of S. aureus bacteria. S. aureus bacteria are sensitive only at 100% concentration with inhibition zone diameter 21.5 ± 5:35 mm, when given the leaf extract of S. ligustrina , and at a concentration of 75% with a diameter of 14.3 ± 1.32 mm is intermediate. The bacteria behave-resistant to the compound of M. oleifera leaf extract and amoxicillin at all concentrations. Diameter of zones of inhibition amoxicillin equal 9.99 ± 2.02 mm with 100% concentration treatment. While the treatment of M. oleifera leaf extract, at a concentration of 75% and 100%, resulting in the largest inhibition zone each is 3.9 ± 0.64 and 3.82±0.57 mm.

Antibacterial silver nanocluster/silica composite coatings on stainless steel

A coating made of silver nanocluster/silica composites has been deposited, via a radio frequency (RF) co-sputtering technique, for the first time onto stainless steel (AISI 304L) with the aim to improve its antibacterial properties. Different thermal treatments after coating deposition have been applied in order to optimize the coating adhesion, cohesion and its antibacterial properties. Its applicability has been investigated at realistic conditions in a cheese production plant.The physico-chemical characteristics of the coatings have been analyzed by means of different bulk and surface analytical techniques. Field emission scanning electron microscopy (FESEM), X-ray Photoelectron Spectroscopy (XPS), contact angle measurements and atomic force microscopy (AFM) were employed to assess coating morphology, composition, surface roughness, wetting properties, size and local distribution of the nanoparticles within the coating. Tape tests were used to determine the adhesion/cohesion properties of the coating. The amount and time-dependence of released silver in solutions of acetic acid, artificial water, artificial tap water and artificial milk were determined by means of Atomic Absorption Spectroscopy (AAS). The antibacterial effect of the coating was evaluated at different experimental conditions using a standard bacterial strain of Staphylococcus aureus in compliance with National Committee for Clinical Laboratory Standards (NCCLS) and AATCC 147 standards. The Ahearn test was performed to measure the adhesion of bacteria to the coated stainless steel surface compared with a control surface.The antibacterial coating retained its antibacterial activity after thermal treatment up to 450°C and after soaking in common cleaning products for stainless steel surfaces used for e.g. food applications. The antibacterial capacity of the coating remained at high levels for 1-5days, and showed a good capacity to reduce the adhesion of bacteria up to 30days. Only a few percent of silver in the coating was released into acetic acid, even after 10days of exposure at 40°C. Most silver (>90%) remained also in the coating even after 240h of continuous exposure. Similar observations were made after repeated exposure at 100°C. Very low levels of released silver in solution were observed in artificial milk. No release of silver nanoparticles was observed either in synthetic tap water or in artificial milk at given conditions.The coating further displayed good antibacterial properties also when tested during working conditions in a cheese production plant.

Frequency of Biliary Infection and Antimicrobial Susceptibility Pattern in Patients with Extra-Hepatic Biliary Obstruction Undergoing Non-Surgical Interventions with Reused Accessories

1.1.Introduction: Data of the frequency of biliary infection in patients of obstructive jaundice, the microbial spectrum and antibiotic sensitivity from Asia is scant. We undertook a prospective study to evaluate the frequency and nature of biliary infection in patients with obstructive jaundice. 1.2.Material and methods:Bile samples collected from patients undergoing biliary drainage for Extra Hepatic Biliary Obstruction (EHBO) were cultured by standard microbiological methods and sensitivity to common antibiotics assessed as per National Committee for Clinical Laboratory Standards (NCCLS) guidelines. 1.3.Results and discussion: Of the total 301 EHBO patients presenting to hospital and included in study prospectively, 154 were male, 147 were female. N= 208 patients underwent Endoscopic Retrograde Cholangio Pancreatography (ERCP), 93 patients underwent Percutaneous Transhepatic Biliary Drainage (PTBD). Total 212 (70%) of the patients had clinical cholangitis. Bacteria were isolated in 396 (78%) of the 505 bile samples. Bacteribilia was found more often in benign EHBO (85%) than in malignant (73%, p=0.001), in patients with cholangitis (91%) than without cholangitis (58%, P<0.00001) and in those with post procedure status (94%) than naive (60%, p<0.00001). Poly microbial cultures obtained in 189(50%) of positive samples were more common in cholangitis (47%) than non cholangitis group (19%, p<0.00001) and in post biliary procedure status (49%) than in naive (43%, P=0.0005). Gram-negative bacilli were isolated in 485(83%) (Escherichia coli 50%, Pseudomonas 25%, Citrobacter 7%, Klebsiella 7.4%, Proteus 5.6%) and Gram positive cocci in 17 % (Enterococcus 83%). Gram negative bacilli were sensitive to Carbapenems, Amikacin and Piperacillin-tazobactam but show a high frequency of resistance to 3rd generation cephalosporins and quinolones. Gram positive cocci were more sensitive to Vancomycin, Teicoplanin and Amoxicillin. 1.4.Conclusion:Bacteribilia is seen in 78% of bile samples, bacteribilia is more common in those with clinical cholangitis, benign etiology and a history of previous biliary procedure. Poly microbial culture positivity is more common in those with cholangitis and post procedure status. Gram negative bacteria showed high frequency of resistance to 3rd generation cephalosporins and quinolones.

Severe Ocular Bacterial Infections: A Retrospective Study Over 13 Years

ABSTRACTPurpose: To report data of samples collected from January 2000 to August 2013, in the Department of Diagnosis and Laboratory Analysis, Ophthalmic Hospital, Turin, Italy, from different types of ocular infections and their antibiotic susceptibility.Methods: Collected samples were cultured using both liquid and solid media. Then bacterial isolates were tested for antibiotic susceptibility using the Kirby–Bauer diffusion method and the National Committee for Clinical Laboratory Standards (NCCLS) serum standards.Results: Staphylococcus aureus is the most common bacteria isolated in ocular samples.Conclusions: In vitro susceptibility tests showed that levofloxacin and moxifloxacin (introduced only in 2010) had the highest efficacy against bacterial isolates.