Sidrah Saleem

Evaluation of the antibacterial activity of selected Pakistani honeys against multi-drug resistant Salmonella typhi

BackgroundThe development of resistance to conventional anti-typhoid drugs and the recent emergence of fluoroquinolone resistance have made it very difficult and expensive to treat typhoid fever. As the therapeutic strategies become even more limited, it is imperative to investigate non-conventional modalities. In this context, honey is a potential candidate for combating antimicrobial resistance because it contains a broad repertoire of antibacterial compounds which act synergistically at multiple sites, thus making it less likely that the bacteria will become resistant. The in vitro antibacterial activity of 100 unifloral honey samples against a blood culture isolate of multi-drug resistant (MDR) Salmonella typhi were investigated.MethodsAll honey samples were evaluated for both total (acidity, osmolarity, hydrogen peroxide and non-peroxide activity) and plant derived non-peroxide antibacterial activity by agar well diffusion assay at 50% and 25% dilution in sterile distilled water and 25% in catalase solution. Manuka (Unique Manuka Factor-21) honey was used for comparison. The phenol equivalence of each honey sample from 2% to 7% (w/v) phenol was obtained from regression analysis. The antibacterial potential of each honey sample was expressed as its equivalent phenol concentration. The honey samples which showed antibacterial activity equivalent to or greater than manuka honey were considered therapeutically active honeys.ResultsNineteen honey samples (19%) displayed higher hydrogen peroxide related antibacterial activity (16–20% phenol), which is more than that of manuka honey (21-UMF). A total of 30% of the honey samples demonstrated antibacterial activity between 11 and 15% phenol similar to that of manuka honey while 51% of the honey samples did not exhibit any zone of inhibition against MDR-S. typhi at 50% (w/v) dilution. None of the indigenous honey samples displayed non-peroxide antibacterial activity. Only manuka honey showed non-peroxide antibacterial activity at 25% dilution (w/v) in catalase solution.ConclusionsThe honey samples which displayed antibacterial activity equal to or greater than manuka honey may be useful in the clinical conditions where higher hydrogen peroxide related antibacterial activity is required. Manuka honey, which is known to possess non-peroxide antibacterial activity, warrants further evaluation in a suitable typhoid animal model.

In vitro and in vivo activity of Manuka honey against NDM-1-producing Klebsiella pneumoniae ST11

AIM To determine the therapeutic potential of Manuka honey against New Delhi metallo-β-lactamase-1-producing Klebsiella pneumoniae ST11 in vitro and in vivo. MATERIALS & METHODS Carbapenamases and metallo-β-lactamases-producing K. pneumoniae ST11 isolated from blood culture was confirmed by VITEK-2® system, matrix-assisted laser desorption ionization-time of flight and multilocus sequence typing, followed by determination of minimum inhibitory concentration (μg/ml) using VITEK-2 system. Genetic analysis of bla NDM-1 was done by PCR, pulsed-field gel electrophoresis and DNA hybridization. In vitro and in vivo efficacy of Manuka honey was performed by microbroth dilution assay and BALB/c mice model respectively. RESULTS K. pneumoniae ST11 displayed resistance to commonly used antibiotics. bla NDM-1 was located on 150 and 270kb plasmids. Minimum inhibitory concentration and minimum bactericidal concentration of Manuka honey was 30% (v/v) and substantial reduction of bacterial mean log value (>1 log) was observed in mice. Histological analysis of mice liver and kidneys demonstrated mild to moderate inflammation. CONCLUSION Manuka honey can be used as an alternate therapeutic approach for management of New Delhi metallo-β-lactamase-producing pathogens.

First identification of clinical isolate of a Novel “NDM-4” producing Escherichia coli ST405 from urine sample in Pakistan

New Delhi metallo-lactamase producing Enterobacteriaceae are a serious threat to the public health sectors worldwide. NDM producing pathogens generally display resistance against several different classes of antibiotics including carbapenems; considered last resort to treat infections caused by such pathogens.1,2 Until now 19 NDM variants (NDM-1 to NDM-19) have been identified from different parts of the world http://www.lahey.org/Studies/other.asp. NDM-4 differs from NDM-1 by a single point mutation at position 154 (M–L) and is associated with high carbapenemase activity.3 We are first time reporting the description of NDM-4 producing Escherichia coli isolated from urine sample in Pakistan. A 4-year-old female patient was hospitalized in a tertiary care hospital Lahore, Pakistan in March 2014. After admission, her urine culture revealed the presence of E. coli which was confirmed by VITEK ® 2 system (bioMerieux, France) and MALDI-TOF (Bruker, Germany). Isolate was also carbapenemase and metallo-lactamase producer identified by modified Hodge’s test and double disk synergy method respectively.4 Minimum inhibitory concentration ( g/mL) of antibiotics using GN XN05 card in VITEK ® 2 compact system (bioMerieux, France) displayed pan-drug resistance to commonly used antibiotics including meropenem and only effective drug was colistin. Furthermore, colistin susceptibility was determined by broth microdilution assay

A Novel Complementary Alternative Medicine: An In-Vitro Evaluation of Efficacy of Nigella sativa Extract as an Antibacterial Agent against Porphyromonas gingivalis

Introduction: Periodontitis is an inflammatory disease which causes progressive destruction of the periodontium resulting in pocket formation, gingival recession and tooth loss. The overwhelming cost of periodontal treatment, unpleasant side effects of antibiotics, emergence of new bacterial strains and their resistance call for an alternative treatment modality which can address all these issues. Nigella sativa is an annual herbaceous plant. It is commonly known as black seed which has been used for more than 2000 years as a natural remedy. Numerous studies have confirmed the biological functions of black seed and demonstrated its anti-inflammatory, antimicrobial, antifungal and anticancer activity. Objective: To determine the frequency of Porphyromonas gingivalis in chronic periodontitis patients and evaluate the efficacy of black seed extract against it. Methodology: Porphyromonas gingivalis was isolated from subgingival plaque samples and identified up to species level. Ethanolic extract of black seed was screened for antibacterial activity by agar well diffusion and agar dilution method. A reference strain of Porphyromonas gingivalis ATCC 33277 was used as quality control. Results: All the tested strains of Porphyromonas gingivalis were sensitive to ethanolic extract of black seed at concentrations 25, 50, 75 and 100%. The extract had an MIC range of 2-4mg/ml. Conclusion: These results indicate that ethanolic extract of black seed has potent antibacterial activity against Porphyromonas gingivalis. So black seed extract can be used in periodontal therapy as an adjuvant to scaling.

Non-O1Vibrio cholerae bacteremia in an infant, first case report from Pakistan

To the best of our knowledge, Non-O1 Vibrio cholerae (NOVC) bacteremia has never been documented in Pakistan. This case report is the first reported case of bacteremia in an infant due to NOVC in Pakistan. A neonate was admitted to a hospital with fever and no history of diarrhea. The isolate was identified biochemically and serologically and was sensitive to all the drugs tested as per CLSI 2014 guidelines.