An International Peer Reviewed Open Access Journal

May 2016 Volume 2 Issue 4

1. Limitations of the current chemical neutralization tests for assessment of microbial recovery from antimicrobials: A new prospective approach (PERSPECTIVE)

Mostafa Essam Eissa*PDF-Download

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Neutralization of antimicrobial properties is considered as a crucial aspect when considering an evaluation of efficacy of biocidal products and microbial recovery of microorganisms from hostile chemical environment. Chemical neutralization method is considered one of these main important techniques for neutralizing antimicrobial properties of the biocidal agents. However, unless reaction time is nearly instantaneous the declining antimicrobial concentration will take time that may affect the survival and recovery of the organism. In general, the duration is uncontrolled and contingent which leads to biased and/or exaggerated estimation of the true potency of the antimicrobial activity and possibly a low microbial recovery from the environmental monitoring (EM) samples. A thorough review on the preparation of protocols for the chemical neutralization is required in order to determine the significance and influence of the reaction time for the diminishing antimicrobial compounds. The consequences of stressed or injured microbial cells due to the exposure to harsh chemical environment may lead to a viable but not culturable (VBNC) state in which no colonies can be observed in a conventional culture medium. This may lead to overestimated potency of the true biocidal activity. This fact highlighted the importance of the application of new advanced technologies for the enumeration of the viable microbial particles using rapid microbiological methods (RMMs). In healthcare providing facilities, proper disinfection program must be ensured to face the ever growing list of objectionable microbes that affect human health.

Key words:  Biocidal, environmental monitoring, microbial recovery, neutralization, reaction time.
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2. Prevalence and antifungal susceptibility pattern of Candida albicans isolated from patients with suspected candidiasis – A study from South Karnataka (RESEARCH ARTICLE)

Faseela Taivalap Shafi, Sunil Rao Padmaraj and Raja Gopal KPDF-Download

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The incidence of candidiasis has increased drastically in last few decades. The distribution pattern of Candida in invasive infections varies widely in different geographical area. C. albicans is the major pathogen in most part of the world. Antifungal resistance is one of the important problems among Candida including C. albicans. Aim of this study was to determine the prevalence and antifungal susceptibility pattern of C. albicans isolated from patients. Candida isolated from various clinical specimens were identified and antifungal susceptibility test was performed by disk diffusion method. The prevalence of Candida albicans was 49%. C. albicans exhibited various degree of resistance to azoles. Resistance was highest in itraconazole followed by ketoconazole. All C. albicans isolates were sensitive to amphotericin B. Even though there is progressive shift from a predominance of Candida albicans to non-albicans Candida species in candidiasis, C. albicans remains as the most important pathogen. Since azole resistance is increasing, accurate identification of Candida species and antifungal susceptibility testing is crucial for patient management and for facilitating hospital control measures.

Key words:  Candidiasis, antifungal susceptibility, disk diffusion, Candida, azole.
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3. Validation of rapid sterility test with BacT/ALERT 3D on human mesenchymal stem cells as cell therapy product inside an hospital cell factory (RESEARCH ARTICLE)

V. Becherucci*, F. Gentile, R. Ceccantini, V. Gori, L. Piccini, S. Bisin, E. Allegro, F. Brugnolo, B. Bindi, P. Pavan,
V. Cunial, S. Ermini and F. BambiPDF-Download

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Sterility of cell therapy products must be ensured through a rapid test using automated culture systems, according to EuPharmacopoeia chapter 2.6.27. The aim of this study was to validate the rapid sterility test with BacT/ALERT 3D system for microbiological control of Human Mesenchymal Stem Cells (hMSC) cultures from Bone Marrow comparing it to classic sterility test and analyzing method sensitivity, precision (repeatability and reproducibility) and specificity according to EMEA guidance on process validation and Good Manufacturing Practices facilities. Suspensions of 10 microorganisms recommended by the European Pharmacopoeia, plus one species internally isolated, were inoculated in SA and SN culture bottles and incubated in a BacT/ALERT 3D automated culture system at two different concentrations (1-10 UFC and 10-100 UFC), contaminating 3 matrices in triplicate for three bottle batches. The same inocula were carried out in the same way in FTM and TSB medium in order to compare the rapid sterility test with classic sterility test described by European Pharmacopoeia and assess method reliability. Most of inoculated microorganisms were detected in less than 2 day and the study demonstrated that the BacT/ALERT 3D system can detect both aerobic and anaerobic bacterial and fungal contamination of MSC for cell therapy according to European Pharmacopoeia recommendations. This study validated  the specificity, sensitivity, and precision of the BacTALERT 3D method showing the  detection of  microbial growth faster than the classic sterility test and without significative differences about number of positive cultures detected between the two methods. Our data suggest that the BactALERT 3D system can be used as GMP validate system for detection of microbial growth in cell therapy product, providing positive growth results within 3 days of incubation, negative results within 7 days and safety related to the absence of interference in microbial growth detection.

Key words:  Good Manufacturing Practices, Validation Protocol, Sterility test, Cell Therapy Products, Microbiological control, Quality Control.
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4. Isolation of antibiotic producing Actinomycetes from soil of Kathmandu valley and assessment of their antimicrobial activities (RESEARCH ARTICLE)

Masna Rai*, Nisha Bhattarai, Nisha Dhungel and Pappu Kumar MandalPDF-Download

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The purpose of this study was to isolate the antibiotic producing actinomycetes from soil from different parts of Kathmandu valley and to access their antimicrobial activity against different pathogenic bacteria like Staphylococcus aureus (ATCC 25923), Escherichia coli(ATCC 25922) and Pseudomonas aeruginosa (ATCC 27853). This study also focuses on investigating the distribution of the antibiotic producing actinomycetes according to the texture and cultivation status of soil.  Fifty four colonies of actinomycetes were isolated from the soil collected from five different parts of Kathmandu valley in the standard medium out of which 20 colonies produced antibiotics; all of them belonged to genus Streptomyces. One of the isolated colony largely inhibited the growth of E. coli and Staphylococcus aureus with zone of inhibition more than 20 mm for both. Antibiotic from this colony was produced by submerged fermentation and the minimum inhibitory concentration of the crude antibiotic was determined.

Key words:  Actinomycetes, Antibiotics, Streptomyces, Submerged Fermentation.
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5. Activity of antibiotic combinations against multidrug resistant Pseudomonas aeruginosa: A study from South India (RESEARCH ARTICLE)

Rouchelle Charmaine Tellis*, Sachin Vidyasagar and M.S Moosabba
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Infections caused by MDR pathogens are a therapeutic challenge as they are resistant to most of the antibiotics used in clinical practice. Combination antimicrobial therapy usually involving a carbapenem is frequently considered as the last viable strategy to treat such infections. Often antibiotics in combination therapy are empirically selected on basis of intuition and anecdotal reports. This study aims to determine in-vitro efficacy of antibiotic combinations devoid of carbapenems on MDR P. aeruginosa which will reveal the potential synergy between two antibiotics belonging to different chemical classes, especially when resistance to any one of them is present. Outcome of this study is expected to help in drafting healthy antibiotic policies and taking the pressure off carbepenems which are currently used overwhelmingly in clinical practice. This study was undertaken with the objective of studying the in-vitro effect of the following antibiotic combinations by chequer board assay: ceftazidime- amikacin, ceftazidime-ciprofloxacin, imepenem-amikacin and imepenem-ciprofloxacin, in 68 MDR clinical isolates of P. aeruginosa.  CAZ- AMK and IMP-AMK combinations showed synergistic effect in 80%-90% of MDR isolates with FICI ≤0.5. Higher rates of indifference (0.5>FICI≤2) and antagonism (FICI>2) were observed with combinations involving fluroquinolones. This study proves that in vitro antimicrobial activity of antibiotic combinations having 3rd or 4th generation cephalosporin with aminoglycosides is comparable to that of imepenem tested alone or in combination. Therefore combinations devoid of carbepenems should be advocated to prolong the clinical usefulness of this antibiotic group.

Key words:  Combination antibiotics, imepenem, multi drug resistant, Pseudomonas aeruginosa.
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