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Background: Carbapenem-resistant A. baumannii (CRAB) bacterium is difficult to treat with available antimicrobial agents leading to use a few antibiotics such as colistin as an option for treatment. However, the use of the colistin has serious side effects and leads to developing bacterial resistance. Objective: This study aimed to determine effectiveness of phage/colistin combination to inhibit biofilm formation of CRAB. Methods: Sixty clinical A. baummanii isolates were identified with the VITEKII system and 16S rRNA gene. The antibiotic susceptibility and detection of Oxacillinases genes were tested for all isolates. Results: The antibiotic sensitivity of A. baumannii isolates showed a high resistance percentage to Ceftriaxone (CRO) with 92% (55 isolates), and Cefotiam (CTF) with 87% (52 isolates), while the lowest percent related to Colistin (CO) with 17% (10 isolates). The results of antibiotic resistance and Oxacillinases genes reported that only 14 isolates from the current study were CRAB. Phage and host A. baumannii of phage were isolated and characterized previously. Biofilm production assay of CRAB isolates were showed that among 14 isolates including the phage host: 57% (8) was weak and 43% (6) was moderate biofilm producer. Therefore, the synergistic effect of a combination ΦKAB phage in MOI (10) and Colistin with MIC=8 µg/ml against CRAB isolates was evaluated and showed complete transfer of isolates by 100 % to weak biofilm producer compared with CRAB isolates. Conclusions: Among 60 isolates of A. baumannii, most isolates were MDR 44 (73.3%) and only 14 (23.3%) isolates were CRAB that were 57% weak and 43% moderate biofilm producers. The mixture of Colistin/ΦKAB phage could inhibit and reduce biofilm forming in CRAB isolates. Overall, the present study may provide evidence on the capability of the isolated phage to serve as a novel strategy to treat infections caused by MDR A. baumannii. [ABSTRACT FROM AUTHOR]

Copyright of Al-Mustansiriyah Journal of Science is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Al-Mustansiriyah Journal of Science is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Acinetobacter baumannii has become a major concern for scientific attention due to extensive antimicrobial resistance. This resistance causes an increase in mortality rate because strains resistant to antimicrobial agents are a major challenge for physicians and healthcare workers regarding the eradication of either hospital or community-based infections. These strains with emerging resistance are a serious issue for patients in the intensive care unit (ICU). Antibiotic resistance has increased because of the acquirement of mobile genetic elements such as transposons, plasmids, and integrons and causes the prevalence of multidrug resistance strains (MDR). In addition, an increase in carbapenem resistance, which is used as last line antibiotic treatment to eliminate infections with multidrug-resistant Gram-negative bacteria, is a major concern. Carbapenems resistant A. baumannii (CR-Ab) is a worldwide problem. Because these strains are often resistant to all other commonly used antibiotics. Therefore, pathogenic multi-drug resistance A. baumannii (MDR-Ab) associated infections become hard to eradicate. Plasmid-mediated resistance causes outbreaks of extensive drug-resistant. A. baumannii (XDR-Ab). In addition, recent outbreaks relating to livestock and community settings illustrate the existence of large MDR-Ab strain reservoirs within and outside hospital settings. The purpose of this review, proper monitoring, prevention, and treatment are required to control (XDR-Ab) infections. Attachment, the formation of biofilms and the secretion of toxins, and low activation of inflammatory responses are mechanisms used by pathogenic A. baumannii strain. This review will discuss some aspects associated with antibiotics resistance in A. baumannii as well as cover briefly phage therapy as an alternative therapeutic treatment. [ABSTRACT FROM AUTHOR]

Objective: In this study, we investigated the anti-inflammatory activity of marine Brevibacterium aureum and its major constituent's saphenic acid a derivative of 1-phenazinecarboxylic acid on induction of inducible pro-inflammatory cytokines, in lipopolysaccharide (LPS)-stimulated macrophages cells.Methods: The marine samples were collected and tested for its anti-cancer activity using MTT assay protocols. The effects of saphenic acid on macrophages was tested by AO/EB staining, cell cycle, and tunnel assay. The expression of pro-inflammatory mediators in macrophages was evaluated with western blot. The inhibitory effects of saphenic acid on the activation of signalling pathways in macrophages were evaluated by western blot analysis.Results: The strain identified as Brevibacterium aeureum species exhibit potential in vitro cytotoxicity on MCF-7, HeLa and HCT-116 showed optimal anticancer activity when compared to standard. Its major constituent's saphenic acid significantly suppressed levels of expression of LPS-induced NF-κB and phosphorylation of MAPKs (ERK1/2, JNK, and p38).Conclusion: Collectively, data from this study suggest that B. aureum and its major fraction saphenic acid have the potency of anticancer activities, which is effected via inhibition of NF-κB and MAPK signaling pathways, and thus holds promise for treatment of inflammatory disease. [ABSTRACT FROM AUTHOR]

In silico analyses identified a Crp/Fnr family transcription factor (HcpR) in sulfate-reducing bacteria that controls expression of the hcp gene, which encodes the hybrid cluster protein and contributes to nitrosative stress responses. There is only one hcpR gene in the model sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough, but two copies in Desulfovibrio desulfuricans 27774, which can use nitrate as an alternative electron acceptor to sulfate. Structures of the D. desulfuricans hcpR1, hcpR2 and hcp operons are reported. We present evidence that hcp expression is regulated by HcpR2, not by HcpR1, and that these two regulators differ in both their DNA-binding site specificity and their sensory domains. HcpR1 is predicted to be a b-type cytochrome. HcpR1 binds upstream of the hcpR1 operon and its synthesis is regulated coordinately with hcp in response to NO. In contrast, hcpR2 expression was not induced by nitrate, nitrite or NO. HcpR2 is an iron-sulfur protein that reacts with NO and O2. We propose that HcpR1 and HcpR2 use different sensory mechanisms to regulate subsets of genes required for defense against NO-induced nitrosative stress, and that diversification of signal perception and DNA recognition by these two proteins is a product of D. desulfuricans adaptation to its particular environmental niche. [ABSTRACT FROM AUTHOR]