Synergistic antimicrobial activity of <i>Camellia sinensis</i> and <i>Juglans regia</i> against multidrug-resistant bacteria

Synergistic combinations of antimicrobial agents with different mechanisms of action have been introduced as more successful strategies to combat infections involving multidrug resistant (MDR) bacteria. In this study, we investigated synergistic antimicrobial activity of Camellia sinensis and Juglans regia which are commonly used plants with different antimicrobial agents. Antimicrobial susceptibility of 350 Gram-positive and Gram-negative strains belonging to 10 different bacterial species, was tested against Camellia sinensis and Juglans regia extracts. Minimum inhibitory concentrations (MICs) were determined by agar dilution and microbroth dilution assays. Plant extracts were tested for synergistic antimicrobial activity with different antimicrobial agents by checkerboard titration, Etest/agar incorporation assays, and time kill kinetics. Extract treated and untreated bacteria were subjected to transmission electron microscopy to see the effect on bacterial cell morphology. Camellia sinensis extract showed higher antibacterial activity against MDR S. Typhi, alone and in combination with nalidixic acid, than to susceptible isolates.” We further explore anti-staphylococcal activity of Juglans regia that lead to the changes in bacterial cell morphology indicating the cell wall of Gram-positive bacteria as possible target of action. The synergistic combination of Juglans regia and oxacillin reverted oxacillin resistance of methicillin resistant Staphylococcus aureus (MRSA) strains in vitro. This study provides novel information about antimicrobial and synergistic activity of Camellia sinensis and Juglans regia against MDR pathogen

Drug resistance profile and biofilm forming potential of Pseudomonas aeruginosa isolated from contact lenses in Karachi-Pakistan

BACKGROUND: The contaminated contact lens provides Pseudomonas aeruginosa an ideal site for attachment and biofilm production. Continuous contact of the eye to the biofilm-infested lens can lead to serious ocular diseases, such as keratitis (corneal ulcers). The biofilms also prevent effective penetration of the antibiotics, which increase the chances of antibiotic resistance. METHODS: For this study, 22 Pseudomonas aeruginosa isolates were obtained from 36 contact lenses and 14 contact lens protective fluid samples. These isolates were tested against eight commonly used antibiotics using Kirby-Bauer disk diffusion method. The biofilm forming potential of these isolates was also evaluated using various qualitative and quantitative techniques. Finally, a relationship between biofilm formation and antibiotic resistance was also examined. RESULTS: The isolates of Pseudomonas aeruginosa tested were found resistant to most of the antibiotics tested. Qualitative and quantitative biofilm analysis revealed that most of the isolates exhibited strong biofilm production. The biofilm production was significantly higher in isolates that were multi-drug resistant (p < 0.0001). CONCLUSION: Our study indicates that multi-drug resistant, biofilm forming Pseudomonas aeruginosa isolates are mainly involved in contact lens associated infections. This appears to be the first report from Pakistan, which analyzes both antibiotic resistance profile and biofilm forming potential of Pseudomonas aeruginosa isolates from contact lens of the patients with contact lens associated infections

Evidence for a Founder Effect among HIV-infected injection drug users (IDUs) in Pakistan.

Background: We have previously reported a HIV-1 subtype A infection in a community of injection drug users (IDUs) in Karachi, Pakistan. We now show that this infection among the IDUs may have originated from a single source. Methods: Phylogenetic analysis was performed of partial gag sequences, generated using PCR, from 26 HIV-positive IDU samples. Results: Our results showed formation of a tight monophyletic group with an intra-sequence identity of \u3c 98% indicating a founder effect . Our data indicate that the HIV-1 epidemic in this community of IDUs may have been transmitted by an HIV positive overseas contract worker who admitted to having contact with commercial sex workers during stay abroad. Conclusion: Specific measures need to implemented to control transmission of HIV infection in Pakistan through infected migrant workers

Prevalence, diversity and disease association of <i>Helicobacter pylori</i> in dyspeptic patients from Pakistan

Introduction: The etiological association of Helicobacter pylori with gastric ulcer (GU), gastric cancer (GC), and duodenal ulcer (DU) is well-known. Understanding the epidemiology of H. pylori facilitates the estimation of disease burden in a certain population. This study presents the diversity of H. pylori genotypes and their association with different clinical outcomes among dyspeptic patients in Pakistan over a period of four years. Methodology: Gastric biopsy samples from a total of 450 dyspeptic individualswere subjected to PCR, genotypingand histology. Results: A total of 201 (45%) cases were found positive for H. pylori. The detection rate was high in GU (91%), DU (86%) and GC (83%) cases compared with those cases who had intact gastric mucosa (18%). Histology revealed the presence of infection in 68% of cases of mild/chronic nonspecific gastritis with others belonging to the GU sequel. cagA gene carriage was observed in 104 (51%) cases or mostly from DU, GU and GC groups, of which 97 were Western type strains while 3 were East-Asian type strains that are rarely observed in South Asia. vacA allelic variant s1am1 was most commonly observed, followed by s1am2, and s1bm1, with direct correlation in diseased cases (gastritis, GU, DU and GC). Prevalent genotypic combinations were s1am1/cagA- in gastritis and s1am1/cagA+ in DU, GU, and GC. Conclusions: Our study indicates the predominant circulation of Western type cagA and vacAs1am1 type H. pylori strains in Pakistan.</br

Prevalence of HCV and HIV infections in 2005-Earthquake-affected areas of Pakistan

<p>Abstract</p> <p>Background</p> <p>On October 8, 2005, an earthquake of magnitude 7.6 hit the Northern parts of Pakistan. In the post-earthquake scenario, overcrowding, improper sewage disposal, contamination of food and drinking water, hasty surgical procedures, and unscreened blood transfusions to earthquake victims most likely promotes the spread of infections already prevalent in the area.</p> <p>Objective</p> <p>The objective of the study reported here was to determine the prevalence of Human Immunodeficiency and Hepatitis C viruses (respectively, HIV and HCV) in the earthquake-affected communities of Pakistan. The samples were analyzed 2 months and then again 11 months after the earthquake to estimate the burden of HIV and HCV in these areas, and to determine any rise in the prevalence of these viral infections as a result of the earthquake.</p> <p>Methods</p> <p>Blood samples were initially collected during December, 2005 to March 2006, from 245 inhabitants of the earthquake-affected areas. These samples were screened for HCV and HIV, using immunochromatography and Enzyme-Linked Immuno-Sorbent Assay (ELISA).</p> <p>Results</p> <p>Out of 245 samples tested, 8 (3.26%) were found positive for HCV, and 0 (0.0%) for HIV, indicating the existence of HCV infection in the earthquake-stricken areas. The same methods were used to analyze the samples collected in the second round of screening in the same area, in September, 2006 – 11 months after the earthquake. This time 290 blood samples were collected, out of which 16 (5.51%) samples were positive for HCV, and 0 for HIV.</p> <p>Conclusion</p> <p>A slightly higher prevalence of HCV was recorded 11 months after the earthquake; this increase, however, was not statistically significant. None of the study participants was found HIV-infected.</p

Fluoroquinolones inhibit HCV by targeting its helicase

Background: HCV has infected \u3e170 million individuals worldwide. Effective therapy against HCV is still lacking and there is a need to develop potent drugs against the virus. In the present study, we have employed two culture models to test the activity of fluoroquinolone drugs against HCV: a subgenomic replicon that is able to replicate independently in the cell line Huh-8 and the Huh-7 cell culture model that employs cells transfected with synthetic HCV RNA to produce the infectious HCV particles. Fluoroquinolones have also been shown to have inhibitory activity against certain viruses, possibly by targeting the viral helicase. To tease out the mechanism of the antiviral activity of fluoroquinolones, their effect on HCV NS3 helicase protein was also tested. Methods: Huh-7 cells producing the HCV virion as well as Huh-8 cells were grown in the presence or absence of 12 different fluoroquinolones. Afterwards, Huh-7 and Huh-8 cells were lysed and viral RNA was extracted. The extracted RNA was reverse transcribed and quantified by real-time quantitative PCR. Fluoroquinolones were also tested on purified NS3 protein in a molecular-beacon-based in vitro helicase assay. Results: To varying degrees, all of the tested fluoroquinolones effectively inhibited HCV replication in both Huh-7 and Huh-8 culture models. The inhibition of HCV NS3 helicase activity was also observed with all 12 of the fluoroquinolones. Conclusions: Fluoroquinolones inhibit HCV replication possibly by targeting the HCV NS3 helicase. These drugs hold promise for the treatment of HCV infection

Status of secretor and non-secretor with respect to ABO blood group system in young population in Karachi-Pakistan

The current study was carried out on 550 healthy population having 250 males and 300 females. Five ml venousblood was collected following standard biosafety measures. ABO blood grouping was done by Tile method and found blood group B dominant in both sexes i.e 180 male and 120 female were found with blood group B. Moreover, 2 ml of saliva was also collected from allvolunteers. Secretor status was detected from the saliva byhaemagglutination inhibition method and found 278 female and 234 male were secretors

Effect of <i>Juglans regia</i> on bacterial growth kinetics.

<p>(a) Methicillin resistamt <i>Staphylococcus</i> aureus (MRSA) and (b) <i>S</i>. <i>aureus</i> ATCC 25923 (pan—susceptible) were treated with graded concentrations of aqueous extract of <i>Juglans regia</i> (Dandasa). Growth cycle of untreated organisms served as growth control. A 2Log₁₀ decrease at any time point from original CFU was considered as significant. Results are presented as an average for three experiments.</p