Background: Multi-drug-resistant Acinetobacter baumannii (MDR A. baumannii) infections are an ongoing problem in many hospitals, particularly in intensive care units. One of the most difficult infections to treat is A. baumannii because it forms a biofilm.Objectives: To identify MDR A. baumannii biofilm producers from clinical isolates and detect some biofilm-related genes.Materials and methods: During the period from October 2023 to February 2024, a total of 26 A. baumannii clinical isolates were collected from the laboratory of Ghazi Al-Hariri Hospital, Baghdad, Iraq. The automated VITEK®2 system was used to identify A. baumannii isolates phenotypically. The blaOXA51 gene confirmed A. baumannii isolates genotypically. The microtiter plate test and scanning electron microscopy were performed to assess biofilm formation. The presence of the biofilm-forming genes OmpA and blaPER-1 was evaluated.Results: Overall, most of the specimens were from sputum (38.5%), and all the isolates were MDR with a high resistance percentage to imipenem at 100%, meropenem, ceftriaxone, and ciprofloxacin. The isolates showed 80.77% resistance to trimethoprim/sulfamethoxazole and 100% sensitivity to colistin. The results showed that among the 26 isolates, 31% were moderate biofilm formers, 54% were weak biofilm formers, and only 4 isolates were non-biofilm formers (15%). The occurrence rates of the biofilm-related genes OmpA and blaPER-1 were 16 (61.5%) and 1 (3.8%), respectively.Conclusion: The current study suggests the presence of MDR A. baumannii isolates harbouring the biofilm OmpA and blaPER-1 genes.

The bacterium Acinetobacter baumannii (A. baumannii) causes serious human diseases. The emergence of multidrug-resistant (MDR) A. baumannii has increased the need for alternative treatments. Bacteriophage therapy offers a promising alternative for MDR A. baumannii elimination. This study aimed to isolate, characterize, and identify lytic phage activity. A phage designated RKL was isolated from sewage water of Baghdad Medical City hospital as a possible agent for phage therapy to treat infections caused by A. baumannii. Based on transmission electron microscopy, phage RKL is a siphovirus from the Siphoviridae family of the Caudovirales order. The optimal multiplicity of infection (MOI) was at 10. A total of 54 different clinical isolates and host bacteria were tested by the VITEK®2 system for phenotypic identification and antimicrobial profile. The phage showed a narrow host spectrum by lysing only A. baumannii isolates (15/26). The results suggest that RKL phage has a potential impact in inhibiting MDR A. baumannii infection.

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.

Acinetobacter baumannii is a common cause of nosocomial infections. This bacterium has the ability to survive in different environmental conditions and colonize on biotic and abiotic surfaces to produce biofilm. Biofilm is a structure with three-dimensional of a multicellular complex in which the cells are embedded in an extracellular polymeric substance that was produced by the organism itself. The matrix of biofilm includes ions, proteins, nucleic acids, and polymers of polysaccharides. The crucial factor to form biofilm in A. baumannii is the induction of poly-1,6-N-acetylglucosamine (PNAG), which is a surface polysaccharides and considers a virulence factor essential for adherence and aggregation by many Gram-negative bacteria. Several studies concluded that PNAG is crucial factor to keep the robustness of A. baumannii under stressful and dynamic environmental conditions. A. baumannii pgaABCD locus of four genes (pgaA, pgaB, pgaC, and pgaD) encode proteins, which are involved in the synthesis of PNAG. Using PCR analysis concluded that 91.7% of A. baumannii clinical isolates had pgaABCD genes and microtitration plate method indicated that 25% of the isolates produced strong-biofilm, 71% produced moderate-biofilm and 4% of isolates were nonforming biofilm. Statistical analysis showed a significant correlation P less than 0.0001 between biofilm production and the functional role of four genes of the pgaABCD loci.

Acinetobacter baumannii is a common cause of nosocomial infections. This bacterium is able to survive in hostile environments (desiccation, antimicrobial therapies, nutrient unavailability) beside colonization biotic and abiotic surfaces and form biofilm in hospitals and long-term care institutions. Biofilm is a three-dimensional structure of a multicellular complex in which the cells are embedded in an Extracellular Polymeric Substance (EPS) that was produced by the organism itself. Biofilm matrix contains proteins, ions, nucleic acids, and polysaccharide polymers. The main factor that leads to biofilm formation in A. baumannii is the creation of the exopolysaccharide poly-1,6-N-acetylglucosamine (PNAG), which is a virulence factor required for adhesion and aggregation by many Gram-negative bacteria. Many studies indicated that PNAG is an important factor to keep the integrity of A. baumannii biofilms in a more dynamic and stressful environment. A cluster of four genes (pgaA, pgaB, pgaC, and pgaD) are responsible for PNAG, which is encoded by pgaABCD locus. Therefore, the aim of this work was to detect proteins encoded by this locus using SDS-PAGE gel in A. baumannii isolates. Using PCR analysis to detect 16S rRNA concluded that all 24 isolates showed a positive amplification with 242bp. Acinetobacter baumannii clinical isolates showed high resistance percentage to ampicillin-sulbactam (AMS) and ceftazidime (CAZ) with 100% and 91% respectively. Furthermore, the isolates showed 83.3% for cefepime (FEP) and 70.8% for amikacin (AK), while the isolates showed a variable resistance percentage toward other antibiotics. By using Congo red method indicated that 66.7% were positive to produce biofilm and 33.3 were non-forming biofilm. Protein sequences alignment showed 99%, 99%, 100% and 99% identity for PgaA, PgaB, PgaC and PgaD respectively with protein GenBank database.

Infectious diseases caused by infected tools in the environments are threaten to the safety and public health. Transmission sources of these infectious diseases are unknown, but it is thought that non-living materials called fomites, are the major source of acquired infections. Three hundred and one swabs were taken from different sources and cultured on blood agar to study heamolysis ability of isolated bacteria. In this study, MacConkey agar was used to isolate Gram-negative bacteria and Sabouraud agar (SDA) to isolate fungi. The biofilm formation test was done by Congo red plate assay. 41 (13.6%) bacterial isolates were obtained and (18.27%) of fungi were isolated on Sabouraud agar (SDA). Staphylococcus aureus was the more frequent bacterial species that isolated in this study. 29% of samples showed hemolysin activity on blood agar and 32%of the isolates were biofilm- producer. Results revealed that (7.9%) of Gram-negative bacteria harbored the fimH gene, (9%) harbored the icaA were Gram-positive and 6.3 % of fungal samples had HWP1 gene. Furthermore, (9.3%) from the total samples are bacterial samples harbored hla gene belong to Staphylococcus spp. Furthermore, (5.07%) of tested samples possessed hlyA gene were Gram-negative bacteria. We found in our study that infectious organisms can be transmitted from one individual to another by fomites responsible for acquired infection.

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.

Background and Aim: Colistin is increasingly being used as a "last-line" therapy to treat infections caused by multidrug-resistant (MDR) Acinetobacter baumannii isolates, when essentially no other options are available in these days. The aim of this study was to detect genes associated with colistin resistance in A. baumannii. Methods: One hundred twenty-one isolates of A. baumannii were collected from clinical and environmental samples during 2016 to 2018 in Baghdad. Isolates were diagnosed as A. baumannii by using morphological tests, Vitek-2 system, 16SrRNA PCR amplification, and sequencing. Antibiotic susceptibility test was carried out using disk diffusion method. Phenotypic detection of colistin resistance was performed by CHROMagar™ COL-APSE medium and broth microdilution method for the determination of the minimal inhibitory concentration. Molecular detection of genes responsible for colistin resistance in A. baumannii was performed by PCR. Results: Ninety-two (76%) of the 121 A. baumannii isolates were colistin resistant. Twenty-six (21.5%) of the 121 isolates showed positive growth on CHROMagar Acinetobacter base for MDR. PCR detected mcr-1, mcr-2, and mcr-3 genes in 89 (73.5%), 78 (64.5%), and 82 (67.8%) A. baumannii isolates, respectively. Seventy-eight (64.5%) of the 121 isolates harbored the integron intI2 gene and 81 (66.9%) contained intI3 gene. Moreover, 60 (49.6%) of the 121 isolates were positive for the quorum sensing lasI gene. Conclusion: The presence of a large percentage of colistin-resistant A. baumannii strains in Baghdad may be due to the presence of mobile genetic elements, and it is urgent to avoid unnecessary clinical use of colistin.

Acinetobacter baumannii is an opportunistic bacterial pathogen associated with hospital-acquired infections especially in intensive care units (ICU). Main reasons for A. baumannii acquired infections are high ability to acquire antibiotic resistant and biofilm formation. The formation of biofilm that confers persistent to A.baumannii infections and its immunological response are not studied. A.baumannii isolate originated from endotracheal tube of patients admitted to ICU was recovered and selected for further study based on its biofilm forming ability and adherent property. Immune modulations by A. baumannii biofilms were studied by infected PBTE cell-line with biofilm coated ETT and uncoated ETT, at different time points (6, 12 h). Various cytokines were estimated by ELISA and the mRNA levels were used to evaluate the gene expression using real time PCR. Immune-modulations by AB78 biofilms on ETT was infected the Primary Bronchial/Tracheal Epithelial Cells (PBTE) and it showed that all the cytokines were significantly elevated compared to negative control. IL-1 beta production was more against biofilm grown for 48 h. Increasing of biofilm formation time showed to have significant effect for IL-6 levels, otherwise other cytokines level were comparable at different time hours. The fold change in expression were highly significant for IL-6 and significant for IL-10 and TNF-alpha. Biofilm formed in medical device are capable of up regulating inflammatory cytokines promoting macrophage phagocytosis leading to the assumption that biofilm is not only mechanism at work in the persistence of Bactria on endotracheal tube that leads to development of ventilator associated pneumonia.

There are limited data on genome perceptions of S. pneumoniae using whole genome analysis of clinical strains originated from Iraq. Herein, we report the whole genome analysis of S. pneumoniae IMS597, serotype 33C a highly susceptible strain isolated from a hospitalized patient having nephrotic syndrome with sepsis. Whole genome sequencing of the isolate was performed by next-generation sequencing. Isolate IMS597 was susceptible to Penicillin, Erythromycin, Chloramphenicol, Cefotaxime and vancomycin. Serotyping by sequential multiplex PCR indicated its serotype 10F/10C/33C-F, and Quellung reaction confirmed it as 33C serotype. Multi-locus sequence typing (MLST) of strain IMS597 revealed that it belongs to the sequence type 1701. A multifaceted interaction of capsular type and the various virulence determinants particular to each serotype impact the ability of that strain to cause disease with varying severity.

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. 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. 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). 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.

In this study, a novel isolate of Enterobacter aerogenes isolated from contaminated soils with hydrocarbons had extracellular phytate-degrading activity. Enterobacter aerogenes isolates were identified by biochemical tests and confirmed by16S rRNA gene products (amplified size 211bp) for genotypic detection. The phytase activity was reached to maximum activity when this isolate was cultivated under the optimal conditions which consisted of using minimal salt medium containing 1%(w/v) rice bran as a sole source for carbon and 2% (w/v) yeast extract at pH 5.5 and temperature of 50°C for 48 h. The phytase had purified to homogeneity by 50% ammonium sulphate precipitation, ion exchange and gel filtration chromatography with 75.7 fold of purification and a yield of 30.35%. The purified phytase is a single peptide with approximate molecular mass of 42 kDa as assessed by SDS-PAGE. The highest degradative ability by Enterobacter aerogenes of black oil, white oil and used engine oil had observed after 72 h of incubation. Rapid degradation of black oil and used engine oil had also observed while slow degradation of white oilat all time of incubation. The purified phytase inhibited biofilm formation ability in a dose-dependent manner for all Gram-negative and Gram-positive biofilm-forming bacteria and a significant difference in cell surface hydrophobicity was observed after exposure of planktonic cells to phytase for hour. The hydrolyzing effect of phytase released by Enterobacter aerogenes for complex salts of phosphorus that are insoluble in the soil led to increase of phosphorus concentrations and enhanced the ability of Enterobacter aerogenes to degrade a specific hydrocarbon in contaminated soil so that the phytase has a promising application in bioremediation of contaminated soils with hydrocarbons.

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 O-2. 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.

The Escherichia coli fumarate-nitrate reduction regulator (FNR) protein is the paradigm for bacterial O-2-sensing transcription factors. However, unlike E. coli, some bacterial species possess multiple FNR proteins that presumably have evolved to fulfill distinct roles. Here, three FNR proteins (ANR, PP_3233, and PP_3287) from a single bacterial species, Pseudomonas putida KT2440, have been analyzed. Under anaerobic conditions, all three proteins had spectral properties resembling those of [4Fe-4S] proteins. The reactivity of the ANR [4Fe-4S] cluster with O-2 was similar to that of E. coli FNR, and during conversion to the apo-protein, via a [2Fe-2S] intermediate, cluster sulfur was retained. Like ANR, reconstituted PP_3233 and PP_3287 were converted to [2Fe-2S] forms when exposed to O-2, but their [4Fe-4S] clusters reacted more slowly. Transcription from an FNR-dependent promoter with a consensus FNR-binding site in P. putida and E. coli strains expressing only one FNR protein was consistent with the in vitro responses to O-2. Taken together, the experimental results suggest that the local environments of the iron-sulfur clusters in the different P. putida FNR proteins influence their reactivity with O-2, such that ANR resembles E. coli FNR and is highly responsive to low concentrations of O-2, whereas PP_3233 and PP_3287 have evolved to be less sensitive to O-2.