Background: Quercus gall extracts' ability to kill pathogens in vitro and even removal of chronic drug-resistant infections has been reported by several studies. The current investigation is focused on the action of extracts of Quercus infectoria gall in their sub-inhibitory concentrations on the corresponding bacterial behaviours instead of killing them. Methods: The effect of gall extracts on the quorum sensing (QS) associated virulence of multiple drug resistant Pseudomonas aeruginosa recovered from burns wounds was studied. The influence of different extracts on the production of bacterial virulence and biofilm, and expression of the genes encoding quorum sensing and exotoxin A were investigated. Quorum sensing is a crucial regulator of virulence and biofilm development in Pseudomonas aeruginosa and other medical related microbes. Results: Experiments to characterise and quantify Q. infectoria gall extracts impact on the quorum sensing networks of P.aeruginosa revealed that the expression of las, rhl, and exotoxin A (ETA) genes levels including the associated virulence were reduced by the extracts at their subinhibitory concentrations. Conclusions: The obtained results indicated that extracts of Q. infectoria galls fight infections either by their inhibitory constituents, which vigorously eradicate cells or by disruption of the pathogens quorum sensing system through weakening the virulence and bacterial coordination.

Duhok dam reservoir is situated in Duhok city, Iraq. It is an artificial reservoir which supplies water for crops land and orchard around the canal throughout its path. The objective of this investigation is to assess physical, chemical and microbiological aspects of aquatic ecosystem in the lake. The water quality variables (water temperature, pH, EC, total dissolved nitrogen and phosphate, SO 2 , BOD 5 and microoganisms) were being measured seasonally during 2011. The results reported that high conductivity and sulphate concentrations were recorded during different seasons. Heterotrophic plate count and faecal colifom exceed Iraqi and WHO standards for drinking purposes. Statistically, no differences were found between studied sites for all variables. Microbiological isolates, counts, total occurrence and diversity index were more in sediment than in water samples. The occurrence of mycobiota was surveyed by three isolation methods 19 fungal species assigned to 14 genera were isolated. The most frequent species in order were: Aspergillus spp., Penicillium spp. and Eurotium spp. The occurrence of keratinophilic fungi was detected in the sediment by hair baiting method The most frequent genera isolated in this study were Chrysosporium spp. , Trichophyton spp. and Microsporum spp.

Four species of lactic acid bacteria (LAB) were isolated from homemade yoghurt samples and defined as Lactobacillus acidophilus Lactobacillus bulgaricus, Lactobacillus casei, and Lactobacillus plantarum. Each LAB isolate was tested for its tolerance to acidic environments at pH (7.0, 4.0, and 2.0). All lactobacilli isolated tolerated acid while L. bulgaricus was sensitive to pH 2.0. All four bacteria were resistant to ciprofloxacin. Isolates were further tested for their antimicrobial activity against common pathogenic bacteria such as Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus (MRSA), and Bacillus subtilis using the agar spot method. These lactic acid bacteria were found to inhibit growth of most pathogens tested. The viability of lactobacilli isolates were not affected by storage (for 6 weeks) at-20P o P C and 4P o P C but declined when they were stored at room temperature. Acid tolerance and bacterial antagonistic characteristics of these LAB isolates render them good candidates for consideration as probiotics.

Antimicrobial resistance is regarded as one of the top three terrible events threatening the worldwide existence of humans Here of, Acinetobacter baumannii evolved as the most challenging pathogen threatening to initiate the post-antibiotic era. Their ability to withstand antibiotics is attributed to a set of virulence determinants in particular biofilms which are known to enhance pathogenesis and drug resistance potency. Studies regarding green silver nanoparticles (AgNP)s as an alternative treatment modality to antibiotics increased over recent years. Considering these facts, we aimed to explore the antibiofilm effect of AgNPs in the multi-drug-resistant Acinetobacter baumannii. AgNPs were bio-fabricated by Pseudomonas aeruginosa and characterized via FTIR, UV-Vis, XRD, EDS, and SEM. Well-diffusion was used to screen the antimicrobial effects of AgNPs. Minimal-inhibitory concentrations of AgNPs were determined to study their antibiofilm effect at sub-inhibitory concentrations (SIC). Results showed that all isolates were biofilm producers and portrayed high resistance to the tested antibiotics. Characterization results supported the successful fabrication of crystalline nanoparticles. Exposure of the isolates to the bacteriogenic AgNPs resulted in pronounced inhibition zones and reduced biofilms at SICs values. These results indicate that Pseudomonas aeruginosa can be employed to produce AgNPs with an aptitude to disrupt biofilm development and growth in the multi-drug resistant Acinetobacter ­­­­­baumannii.

Thisstudypresentstheantimicrobialeffectofnaturalsurfacesecretesofsomecommonornamentalplantsleaves(Ficuselastica,PhilodendrombipinnatifidumandAglonema)againstsomepathogenicbacteria(Escherichiacoli,P.aeruginosaandStaph.Aureus),andfungi(MicrosporumgypseumandAspergillusflavus).Itwasconcludedthatalltestedwashingwateroftheplantsleavessecretesexhibitedvariousinhibitoryeffects,bothPhilodendrombipinnatifidumandAglonemacommutatumhadexhibitedmoreantibacterialactivitythanFicuselastica.WhilebothE.coliandP.aeruginosawerebeingmoresensitivethanStaph.aureus.Thesameinhibitoryeffectswereobservedwhentheplantsleavesinoculatedintheirsurfacewithpathogenicbacteria.Incontrasttobacterialinhibitoryeffects,thewashingwaterofnaturalsurfacesecretesoftestedornamentalplantsleavesinducedmyceliumgrowthofbothtestedfungi.MicrosporumgypseummyceliumgrowthinducedmorethanAspergillusflavusespeciallyincaseofthewashingwaterofFicuselasticthathavehighesteffectsat7.5/500mLofmedium.Thisstudyconcludedtheusesofornamentalplantsfortheindoorsandoutdoorstocontrolthegrowthofpathogenicmicrobesandproblemsassociatedwithhospital