Sequencing analysis and efficient biodiesel production by lipase from Pseudomonas aeruginosa.

BACKGROUND: Recently, lipase processing for biodiesel production has shown a global increase as it is considered a potential alternative clean-fuel source. The current study's objective is to investigate of lipolytic activity of lipase produced from different strains of Pseudomonas aeruginosa (P. aeruginosa) in biodiesel production using edible plant oils. The goal is to develop an efficient and cost-effective method for producing inexpensive and environmentally friendly biodiesel. METHODS AND RESULTS: Four P. aeruginosa isolates were obtained from different environmental sources (soil), phenotypically identified, and it was confirmed by the PCR detection of the 16SrRNA gene. The isolated P. aeruginosa strains were screened for lipase production, and the recovered lipase was purified. Besides, the lipase (lip) gene was detected by PCR, and the purified PCR products were sequenced and analyzed. The production of biofuel was conducted using gas chromatography among tested oils. It was found that castor oil was the best one that enhances lipase production in-vitro.

Sequencing analysis of tigecycline resistance among tigecycline non-susceptible in three species of G-ve bacteria isolated from clinical specimens in Baghdad.

BACKGROUND: Recent emergence of high-level tigecycline resistance is mediated by tet(X) genes in Gram-negative bacteria, which undoubtedly constitutes a serious threat for public health worldwide. This study aims to identify tigecycline non-susceptible isolates and detect the presence of genes that are responsible for tigecycline resistance among local isolates in Iraq for the first time. METHODS: Thirteen clinical isolates of Klebsiella pneumonia, Acinetobacter baumannii and Pseudomonas aeruginosa tigecycline non-susceptible were investigated from blood, sputum and burns specimens. The susceptibility of different antibiotics was tested by the VITEK-2 system. To detect tigecycline resistance genes, PCR was employed. RESULTS: Strains studied in this work were extremely drug-resistant and they were resistant to most antibiotic classes that were studied. The plasmid-encoded tet(X), tet(X1), tet(X2), tet(X3), tet(X4), tet(X5), tet(M) and tet(O) genes were not detected in the 13 isolates. The results showed that there is a clear presence of tet(A) and tet(B) genes in tigecycline non-susceptible isolates. All 13 (100%) tigecycline non-susceptible K. pneumoniae, A. baumannii and P. aeruginosa isolates harbored the tet(B) gene. In contrast, 4 (30.77%) tigecycline non-susceptible P. aeruginosa isolates harbored the tet(A) gene and there was no tigecycline non-susceptible A. baumannii isolate harboring the tet(A) gene (0%), but one (7.69%) tigecycline non-susceptible K. pneumoniae isolate harbored the tet(A) gene. A phylogenetic tree, which is based on the nucleotide sequences of the tet(A) gene, showed that the sequence of the local isolate was 87% similar to the nucleotide sequences for all the isolates used for comparison from GenBank and the local isolate displayed genetic diversity. CONCLUSIONS: According to this study, tet(B) and tet(A) play an important role in the appearance of tigecycline non-susceptible Gram-negative isolates.

The predominance of Klebsiella pneumoniae carbapenemase (KPC-type) gene among high-level carbapenem-resistant Klebsiella pneumoniae isolates in Baghdad, Iraq.

BACKGROUND: The serine carbapenemase enzymes (KPC) which produce from bacteria klebsiella pneumoniae today have been emerged as one of the ß-lactamase enzymes that is capable to inactivating the last line of carbapenems. The gene encoding the K. pneumonia (blaKPC) belongs to gene carried on plasmid among Enterobacteriaceae family, which has modulation for the infections control so this study is aimed to spot the presence and evaluate blaKPC gene expression by real-time PCR in local isolates of K. pneumonia. METHODS: Forty-seven of K. pneumonia isolates were isolated from different clinical samples (blood, sputum, urine, wounds and burns) from patients in separate hospitals in Baghdad., Antimicrobial sensitivity test was carried out by vitik-2 system and Kirby- Bauer method. The PCR was employed to detect carbapenemase gene. RESULTS: The results of this study showed that all explored isolates were resistant to Ertapenem, Meropenem and imipenem 47(100%). Phenotypically, all the isolates had carbapenemase which hydrolyzed the carbapenem antibiotics. Furthermore, the isolates showed (100%) resistance to Cefazolin, Ampicillin and Amoxicillin/ Clavulic acid. However, the most effective antibiotic was Levofloxacin (91.5%). The results of conventional PCR technique for the detection of blaKPC gene showed that 38 (80.9%) isolates of carbapenem-resistant K. pneumoniae harboured blaKPC gene (1010 bp), while none carried other carbapenemase genes including blaNDM1, blaVIM and blaIMP genes. High levels of carbapenem resistance was clarified by the imipenem and meropenem MICs determination. All 38 isolates were positive in CNPT. Furthermore, the 38 isolates showed over expression of blaKPC gene compared with housekeeping rpo gene in Real-Time PCR. CONCLUSIONS: According to these results, the resistant isolates to carbapenem were belong to the present and high level expression of blaKPC gene in our local isolates.

Mobilized colistin resistance (mcr) genes from 1 to 10: a comprehensive review.

At the present time, the polymyxin antibiotic colistin is considered a last-line treatment option for severe human infections caused by multi-drug and carbapenem-resistant Gram-negative bacteria. Lately, the vast spread of colistin resistance among bacteria has got great attention worldwide due to its significant role as the last refuge in treating diseases caused by the resistant infectious agents. Therefore, the discovery of plasmid-mediated mobile colistin resistance (mcr) genes raised global public health concerns as they can spread by horizontal transfer and have chances of global dissemination. To date, ten slightly different variants of the mcr-1 gene (mcr-1 to mcr-10) have been identified in different bacteria isolated from animals, foods, farms, humans, and the environment. Therefore, the issue of mcr spread is growing and worsening day after day. In this backdrop, the current article presents an overview of mcr variants, their spread, and the resistance mechanisms they confer. Hence, this paper will advance our knowledge about colistin resistance while supporting the efforts toward better stewardship and proper usage of antimicrobials.

Distribution of Pantoea agglomerans isolates and molecular detection of blaPER-1 ESßL gene: A statistical study.

THE PURPOSE: to study the distribution of Pantoea agglomerans (P. agglomerans) statistically and the presence of blaPER-1 type ESßL in the clinical and environmental isolates. METHODS: During a period of 2014-2015, 895 blood specimens and 438 hospital environmental samples were collected from one children's hospital in Baghdad city. The results of statistical analysis showed there was no relationship between the infection with P. agglomerans and the sex, while there was a relationship between the infection with the P. agglomerans and the place of residence and also the age of patients. RESULT: A total of 23 P. agglomerans were isolated during the study, out of 23 isolates, 13 (56.52%) and 10 (43.48%) were isolated from blood specimens and from hospital environment. All 23 isolates had 100% sensitivity rate to Imipenem and the highest resistant rate was (95.65%) to Ampicillin. Out of 23 P. agglomerans, 14 (60.87%) isolates were positive ESßL producing by the screening test. CONCLUSION: The result of molecular screening of the gene blaPER-1 showed the presence of this gene only in phenotypically ESBL producing isolates, while all negative ESßL producing isolates don't harboring blaPER-1 gene. Out of 14 positive ESßL producing P. agglomerans isolates, 5 (35.71%) were harboring blaPER-1 gene and 9 (64.29%) of positive ESßL producing isolates were don't harboring blaPER-1 gene (significant difference at ≤0.05).

Emergence of NDM-1 among carbapenem-resistant Klebsiella pneumoniae in Iraqi hospitals.

Carbapenems are the last drugs of choice apart from colistin against serious infections caused by Gram-negative bacteria. However, there are increasing number of reports indicating prevailing emergence of metallo-ß-lactamase (MBL)-producing clinical isolates worldwide and among them New Delhi MBL (NDM) is the most prevalent one. This study reports NDM-1 for the first time among Klebsiella pneumoniae from hospitalized patients in Baghdad, Iraq. Fifty-five clinical isolates of K. pneumoniae resistant to carbapenem were investigated from burned wounds, sputum, and blood samples. The susceptibility to different antibiotics was tested by VITEK-2 system. All strains were multidrug-resistant and they showed nine different antimicrobial-resistant patterns (A-I) and the most effective antibiotic on these strains was levofloxacin (85.45%). The phenotypic detection of carbapenemases by MASTDISCS D70C revealed 29 (52.73%) strains were MBL-producing, out of 55 were carbapenem-resistant K. pneumoniae strains. The blaNDM-1 and other MBL genes were detected by conventional PCR and the result showed 37 (67.27%) strains positive for blaNDM-1 gene and only 5 (9.1%) strains harbored blaIMP gene, while all strains were negative for blaVIM, blaSIM, blaGIM, and blaSPM genes. Our results showed the coexistence of both blaNDM-1 and blaIMP genes in three strains of K. pneumoniae, while indicated widespread NDM-1 in Baghdad, Iraq. Hence, it is necessary to follow proper infection control practices and physicians should be aware of the patients with such risk factors.

Chitosan extracted from Aspergillus flavus shows synergistic effect, eases quorum sensing mediated virulence factors and biofilm against nosocomial pathogen Pseudomonas aeruginosa.

The biological methods for extraction of chitosan were used as alternative procedures for chemical methods In biological methods, the chitosan was extracted from A. flavus by using of Lactobacillus paracasei for demineralization and Bacillus subtilis for deproteinization. The yield of extracted chitosan reached to 53.8%, pH was 7.8 and complete solubility in 1% acitic acid. Purified chitosan had the ability to reduce the biofilm forming capacity of P. aeruginosa clearly visible in light microscopic staining and scanning electron microscopy. The QS dependent phenotype and QS regulated gene expression was significantly reduced in the influence of chitosan. A significant decrease in biofilm formation was seen in the presence of chitosan. The chitosan treatment showed a decrease in the expression of lasR and rhlR genes. Same time production of pyocyanin and proteases was also inhibited in dose dependent manner. Chitosan led to increasing antimicrobial activity of antibiotics and had synergism effect, thus chitosan may be a useful adjuvant agent for the treatment of many bacterial infections in combination with antibiotics.

Chitosanase purified from bacterial isolate Bacillus licheniformis of ruined vegetables displays broad spectrum biofilm inhibition.

A number of bacterial species produces chitosanases which has variety of applications because of its high biodegradability, non-toxicity and antimicrobial assets. In the present study chitosanase is purified from new bacterial species Bacillus licheniformis from spoiled vegetable. This novel strain of Bacillus licheniformis isolated from spoilt cucumber and pepper samples has the ability to produce the chitosanase enzyme when grown on chitosan substrate. Study also examined its antibiofilm properties against diverse bacterial species with biofilm forming ability. The purified chitosanase inhibited the biofilm formation ability for all Gram-negative and Gram-positive biofilm-forming bacteria [biofilm producers] tested in this study in congo red agar and microtiter plate's methods. Highly antibiofilm activity of chitosanase was recorded against Pseudomonas aeruginosa followed by Klebsiella pneumoniae with reduction of biofilm formation upto 22 and 29%, respectively compared with [100] % of control. Biofilm formation has multiple role including ability to enhance resistance and self-protection from external stress. This chitosanase has promising benefit as antibiofilm agent against biofilm forming pathogenic bacteria and has promising application as alternative antibiofilm agents to combat the growing number of multidrug resistant pathogen-associated infections, especially in situation where biofilms are involved.