scholarly journals Molecular Characterization of Zinc (Zn) Resistant Bacteria in Banger River, Pekalongan, Indonesia

2018 ◽  
Vol 10 (3) ◽  
pp. 622-628
Author(s):  
Fitri Arum Sasi ◽  
Hermin Pancasakti Kusumaningrum ◽  
Anto Budiharjo
Keyword(s):  
Bacterial Species ◽  
Selective Medium ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Indigenous Bacteria ◽  
Gram Positive Bacteria ◽  
Sequences Analysis

Indigenous bacteria are able to remove the metals contamination in environment. This study aimed to assess the resistance of bacterial species to Zinc (Zn) in Banger River, Pekalongan City. The bacteria from three different parts of Banger River were isolated and inoculated in Zn-selective medium. Then, molecular identification to determine the bacteria species was conducted using polymerase chain reaction (PCR) by applying forward-reverse 16SrRNA gene primers. The sequences analysis was conducted using MUSCLE and MEGA6. There were seven dominant species that possibly resistant to Zn. Approximately, every isolate could reach more than 95 % from 2000 ppm of Zn in the medium. The higher absorption of Zn was found in Z5 isolate. The seven bacteria species were clustered into nine genera i.e. Klebsiela, Xenorhabdus, Cronobacter, Enterobacter, Escherichia, Shigella and Sporomusa known as Gram Negative bacteria and Clostridium and Bacillus as Gram Positive bacteria. In Gram Positive bacteria, especially Bacillus sp, carboxyl group in peptidoglycan play a role as metal binder. In Gram-negative bacteria, lipopolysaccharide (LPS) which is highly anionic component on the outer membrane, able to catch the Zn. Besides that, Enterobacter activates endogen antioxidants such as glutathione peroxidase (GSHPx), glutathione reductase (GR), catalase (CAT) and superoxide dismutase (SOD). The research found there was possible seven novel indigenous bacteria species in Banger that able to remove Zn from the sediment extremely. This finding can be developed as an eco-friendly approach to reduce metals pollution using local microorganisms.

scholarly journals Development of Methionyl-tRNA Synthetase Inhibitors as Antibiotics for Gram-Positive Bacterial Infections

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Omeed Faghih ◽  
Zhongsheng Zhang ◽  
Ranae M. Ranade ◽  
J. Robert Gillespie ◽  
Sharon A. Creason ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Bacterial Species ◽  
Bacterial Load ◽  
Trna Synthetase ◽  
Resistant Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Methionyl Trna Synthetase

ABSTRACT Antibiotic-resistant bacteria are widespread and pose a growing threat to human health. New antibiotics acting by novel mechanisms of action are needed to address this challenge. The bacterial methionyl-tRNA synthetase (MetRS) enzyme is essential for protein synthesis, and the type found in Gram-positive bacteria is substantially different from its counterpart found in the mammalian cytoplasm. Both previously published and new selective inhibitors were shown to be highly active against Gram-positive bacteria with MICs of ≤1.3 μg/ml against Staphylococcus, Enterococcus, and Streptococcus strains. Incorporation of radioactive precursors demonstrated that the mechanism of activity was due to the inhibition of protein synthesis. Little activity against Gram-negative bacteria was observed, consistent with the fact that Gram-negative bacterial species contain a different type of MetRS enzyme. The ratio of the MIC to the minimum bactericidal concentration (MBC) was consistent with a bacteriostatic mechanism. The level of protein binding of the compounds was high (>95%), and this translated to a substantial increase in MICs when the compounds were tested in the presence of serum. Despite this, the compounds were very active when they were tested in a Staphylococcus aureus murine thigh infection model. Compounds 1717 and 2144, given by oral gavage, resulted in 3- to 4-log decreases in the bacterial load compared to that in vehicle-treated mice, which was comparable to the results observed with the comparator drugs, vancomycin and linezolid. In summary, the research describes MetRS inhibitors with oral bioavailability that represent a class of compounds acting by a novel mechanism with excellent potential for clinical development.

scholarly journals Gram-Positive Bacteria Are Potent Inducers of Monocytic Interleukin-12 (IL-12) while Gram-Negative Bacteria Preferentially Stimulate IL-10 Production

2000 ◽  
Vol 68 (6) ◽  
pp. 3581-3586 ◽  
Author(s):  
Christina Hessle ◽  
Bengt Andersson ◽  
Agnes E. Wold
Keyword(s):  
Mononuclear Cells ◽  
Bacterial Species ◽  
Optimal Dose ◽  
Interleukin 10 ◽  
Interleukin 12 ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Ifn Γ

ABSTRACT Interleukin-10 (IL-10) and IL-12 are two cytokines secreted by monocytes/macrophages in response to bacterial products which have largely opposite effects on the immune system. IL-12 activates cytotoxicity and gamma interferon (IFN-γ) secretion by T cells and NK cells, whereas IL-10 inhibits these functions. In the present study, the capacities of gram-positive and gram-negative bacteria to induce IL-10 and IL-12 were compared. Monocytes from blood donors were stimulated with UV-killed bacteria from each of seven gram-positive and seven gram-negative bacterial species representing both aerobic and anaerobic commensals and pathogens. Gram-positive bacteria induced much more IL-12 than did gram-negative bacteria (median, 3,500 versus 120 pg/ml at an optimal dose of 25 bacteria/cell; P < 0.001), whereas gram-negative bacteria preferentially stimulated secretion of IL-10 (650 versus 200 pg/ml; P < 0.001). Gram-positive species also induced stronger major histocompatibility complex class II-restricted IFN-γ production in unfractionated blood mononuclear cells than did gram-negative species (12,000 versus 3,600 pg/ml; P < 0.001). The poor IL-12-inducing capacity of gram-negative bacteria was not remediated by addition of blocking anti-IL-10 antibodies to the cultures. No isolated bacterial component could be identified that mimicked the potent induction of IL-12 by whole gram-positive bacteria, whereas purified LPS induced IL-10. The results suggest that gram-positive bacteria induce a cytokine pattern that promotes Th1 effector functions.

scholarly journals Categorization of Bacterial Pathogens Present in Infected Wounds and their Antibiotic Resistance Profile Recovered from Patients Attending Rizgary Hospital-Erbil

2021 ◽  
Vol 9 (2) ◽  
pp. 64-70
Author(s):  
Ahmed A. Al-Naqshbandi ◽  
Hedy A. Hassan ◽  
Mahmoud A. Chawsheen ◽  
Haval H. Abdul Qader
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Staphylococcus Epidermidis ◽  
Resistant Bacteria ◽  
Antibiotic Prescribing ◽  
Gram Negative Bacteria ◽  
Wound Infections ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Wound infection with antibiotic-resistant bacteria can extend a patients’ debility and increase the expense of treatment in the long term; therefore, careful management of patients with wound infections is necessary to avoid complications. The usage of antimicrobial agent is a major factor in resistance development. This study aims to understand the causes of wound infections, as well as the criteria for diagnosing them for more sensible antibiotic prescribing. Samples from 269 wound patients were collected, and cultured for bacterial growth. Gram stain technique, bacterial identification via VITEK 2 compact system were investigated in this study. Gram negative bacteria accounted for 59.15% of the total isolates, while pathogenic gram positive bacteria accounted for 40.85% of total isolates. Escherichia coli and Pseudomonas aeruginosa are the dominant pathogenic gram negative bacteria in wounds, while Staphylococcus aureus, and Staphylococcus epidermidis are the dominant pathogenic gram positive bacteria. Pseudomonas aeruginosa showed 100% resistance to the majority of antibiotic tested, including Ampicillin, Amoxicillin/Clavulanic Acid, Aztreona, Ceftriaxone, and others. Staphylococcus aureus and Staphylococcus epidermidis are 100% resistant to Ampicillin, Ceftriaxone, and Cefotaxime. For more efficient antibiotic prescriptions, the causative microorganisms, and their current susceptibility patterns need to be mandated for testing before prescribing any antibiotics to patients. Prescriptions are frequently based solely on general information about the antibiotic's function, rather than on individual response variation to the pathogen and the antibiotic. Particularly when the common pathogens in this study show multidrug resistance in wounds.

scholarly journals Bacteriological Profile of Tracheal Aspirates of the Patients Attending Neuro-hospital Nepal

2010 ◽  
Vol 4 ◽  
Author(s):  
Pratirodh Koirala ◽  
Dwij Raj Bhatta ◽  
Prakash Ghimire ◽  
Bharat Mani Pokhrel ◽  
Upendra Devkota
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Viridans Streptococci ◽  
Multidrug Resistant Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Tracheal Aspirates

The tracheostomized patients are colonized mostly by gram negative bacteria which lead to either tracheobronchitis or bronchopneumonia. This study was conducted to isolate and identify the potential pathogen causing post tracheostomy infection. A cross-sectional study was conducted during April 2008 to February 2009 based at Neuro Center, Kathmandu. Tracheal aspirates of 50 patients having fever more than 38°C were collected and analyzed for bacterial content. Out of the 50 cases, 45(90%) cases showed bacterial growth. Sixty-seven isolates were identified; with 20(44.4%) poly-microbial cases. Pseudomonas aeruginosa and enteric gram negative bacteria were predominant bacteria (n=27, 40.3%) followed by Staphylococcus aureus (n=7, 10.4%), other Gram negative bacteria (n=4, 5.9%) and Viridans Streptococci (n=2, 2.9%). Pseudomonas aeruginosa were most sensitive to the Amikacin (n=22, 81.4%) and Ciprofloxacin (n=19, 70.3%). All Pseudomonal isolates were resistant to the Cefotaxime. Enteric Gram Negative bacteria (EGNB) were most sensitive to Amikacin and Chloramphenicol (20, 74.0%) and all were resistant to Ampicillin and Cephalexin. All the gram positive bacteria isolated were sensitive to Vancomycin. Among the total isolates, 24 (88.8%) of Pseudomonas aeruginosa, 21 (66.6%) of enteric gram negative bacteria, and 5 (55.5%) of Gram positive bacteria were multidrug resistant (MDR). The study reported alarming condition of MDR in tracheal aspirates. So surveillance for source of multidrug resistant bacteria would be beneficial for intervention of infection related to it. Key words: Tracheal aspirates, polymicrobial growth, Multidrug resistant bacteria (MDR)10.3126/ijls.v4i0.3496International Journal of Life Sciences Vol.4 2010 pp.60-65

scholarly journals Replacement of l-Amino Acids by d-Amino Acids in the Antimicrobial Peptide Ranalexin and Its Consequences for Antimicrobial Activity and Biodistribution

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2987 ◽  
Author(s):  
Cornelius Domhan ◽  
Philipp Uhl ◽  
Christian Kleist ◽  
Stefan Zimmermann ◽  
Florian Umstätter ◽  
...  
Keyword(s):  
Amino Acids ◽  
Antimicrobial Activity ◽  
Antimicrobial Peptide ◽  
The Body ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Strong Antimicrobial Activity

Infections caused by multidrug-resistant bacteria are a global emerging problem. New antibiotics that rely on innovative modes of action are urgently needed. Ranalexin is a potent antimicrobial peptide (AMP) produced in the skin of the American bullfrog Rana catesbeiana. Despite strong antimicrobial activity against Gram-positive bacteria, ranalexin shows disadvantages such as poor pharmacokinetics. To tackle these problems, a ranalexin derivative consisting exclusively of d-amino acids (named danalexin) was synthesized and compared to the original ranalexin for its antimicrobial potential and its biodistribution properties in a rat model. Danalexin showed improved biodistribution with an extended retention in the organisms of Wistar rats when compared to ranalexin. While ranalexin is rapidly cleared from the body, danalexin is retained primarily in the kidneys. Remarkably, both peptides showed strong antimicrobial activity against Gram-positive bacteria and Gram-negative bacteria of the genus Acinetobacter with minimum inhibitory concentrations (MICs) between 4 and 16 mg/L (1.9–7.6 µM). Moreover, both peptides showed lower antimicrobial activities with MICs ≥32 mg/L (≥15.2 µM) against further Gram-negative bacteria. The preservation of antimicrobial activity proves that the configuration of the amino acids does not affect the anticipated mechanism of action, namely pore formation.

scholarly journals BioSAXS measurements reveal that two antimicrobial peptides induce similar molecular changes in Gram-negative and Gram-positive bacteria

2019 ◽  
Author(s):  
A.R. von Gundlach ◽  
M. Ashby ◽  
J. Gani ◽  
P. M. Lopez-Perez ◽  
A. Cookson ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Mode Of Action ◽  
Bacterial Load ◽  
Ultrastructural Changes ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria

AbstractTwo highly active short broad-spectrum AMPs (14D and 69D) with unknown mode of action have been investigated in regards to their effect against the Gram-negative bacteriaE. coliand the Gram-positive bacteria methicillin-resistantStaphylococcus aureus(MRSA). Minimal inhibitory concentration (MIC) measurements using a cell density of 108cfu/ml resulted in values between 16 and 32 μg/ml. Time kill experiments using 108cfu/ml revealed complete killing, except for 69D in combination with MRSA, where bacterial load was reduced a million times. Small angle X-ray scattering of biological samples (BioSAXS) at 108cfu/ml was applied to investigate the ultrastructural changes inE. coliand MRSA in response to these two broad-spectrum AMPs. In addition, electron microscopy (EM) was performed to visualize the treated and non-treated bacteria. As expected, the scattering curves generated using BioSAXS show the ultrastructure of the Gram-positive and Gram-negative bacteria to be very different (BioSAXS is not susceptible to the outer shape). After treatment with either peptide, the scattering curves ofE. coliand MRSA cells are much more alike. This data in conjunction with the EM indicates that ribosomes might be effected by the treatment as well as changes in the nucleoid occurs. Whereas in EM it is notoriously difficult to observe changes for spherical Gram-positives, the BioSAXS results are superior and reveal strongly similar effects for both peptides induced in Gram-positive as well as Gram-negative bacteria. Given the high-throughput possibility and robust statistics BioSAXS can support and speed up mode of action research in AMPs and other antimicrobial compounds, making a contribution towards the development of urgently needed drugs against resistant bacteria.

scholarly journals Increasing the Antimicrobial Activity of Nisin-Based Lantibiotics against Gram-Negative Pathogens

2018 ◽  
Vol 84 (12) ◽  
Author(s):  
Qian Li ◽  
Manuel Montalban-Lopez ◽  
Oscar P. Kuipers
Keyword(s):  
Antimicrobial Peptides ◽  
Outer Membrane ◽  
Rational Design ◽  
Bacterial Species ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Lipid Ii

ABSTRACTLantibiotics are ribosomally synthesized and posttranslationally modified antimicrobial compounds containing lanthionine and methyl-lanthionine residues. Nisin, one of the most extensively studied and used lantibiotics, has been shown to display very potent activity against Gram-positive bacteria, and stable resistance is rarely observed. By binding to lipid II and forming pores in the membrane, nisin can cause the efflux of cellular constituents and inhibit cell wall biosynthesis. However, the activity of nisin against Gram-negative bacteria is much lower than that against Gram-positive bacteria, mainly because lipid II is located at the inner membrane, and the rather impermeable outer membrane in Gram-negative bacteria prevents nisin from reaching lipid II. Thus, if the outer membrane-traversing efficiency of nisin could be increased, the activity against Gram-negative bacteria could, in principle, be enhanced. In this work, several relatively short peptides with activity against Gram-negative bacteria were selected from literature data to be fused as tails to the C terminus of either full or truncated nisin species. Among these, we found that one of three tails (tail 2 [T2; DKYLPRPRPV], T6 [NGVQPKY], and T8 [KIAKVALKAL]) attached to a part of nisin displayed improved activity against Gram-negative microorganisms. Next, we rationally designed and reengineered the most promising fusion peptides. Several mutants whose activity significantly outperformed that of nisin against Gram-negative pathogens were obtained. The activity of the tail 16 mutant 2 (T16m2) construct against several important Gram-negative pathogens (i.e.,Escherichia coli,Klebsiella pneumoniae,Acinetobacter baumannii,Pseudomonas aeruginosa,Enterobacter aerogenes) was increased 4- to 12-fold compared to that of nisin. This study indicates that the rational design of nisin can selectively and significantly improve its outer membrane-permeating capacity as well as its activity against Gram-negative pathogens.IMPORTANCELantibiotics are antimicrobial peptides that are highly active against Gram-positive bacteria but that have relatively poor activity against most Gram-negative bacteria. Here, we modified the model lantibiotic nisin by fusing parts of it to antimicrobial peptides with known activity against Gram-negative bacteria. The appropriate selection of peptidic moieties that could be attached to (parts of) nisin could lead to a significant increase in its inhibitory activity against Gram-negative bacteria. Using this strategy, hybrids that outperformed nisin by displaying 4- to 12-fold higher levels of activity against relevant Gram-negative bacterial species were produced. This study shows the power of modified peptide engineering to alter target specificity in a desired direction.

scholarly journals Incidence and susceptibility patterns of urine bacterial flora in young females

2020 ◽  
Author(s):  
Ashwag Shami ◽  
Samiah Al-Mijalli ◽  
Ali Somily ◽  
Fawziah M. Albarakaty ◽  
Samah Awad AbduRahim
Keyword(s):  
Antimicrobial Susceptibility ◽  
Bacterial Species ◽  
Bacterial Flora ◽  
Resistant Bacteria ◽  
Multiple Drug ◽  
Gram Negative Bacteria ◽  
Culture Methods ◽  
Gram Positive ◽  
Gram Negative ◽  
Susceptibility Patterns

AbstractBackgroundIt has been established that the urinary tract is not sterile, however, research related to the study of urine bacteria are limited. Our work aims to study the frequency and patterns of resistance of normal urinary aerobic bacterial flora.MethodsClean catch midstream urine specimens were collected from 120 young healthy females, and then cultured. Identification of bacteria and antimicrobial susceptibility were done by means of Biomérieux VITEK® 2 automated systems. Subjects who have undergone antimicrobial treatment in one month weren’t included.ResultsThe incidence of positive bacterial cultures was 54.2%, of which 21.5% were ploymicrobial. 107 bacterial isolates that encompass 12 genera and 27 species that were predominated by Gram-positive bacteria (72%) were cultivated. Staphylococcaceae (46.1%) and Enterobacteriaceae (17.8%) were the most frequently isolates among Gram positive and Gram negative bacteria respectively, from them 36 species have been identified as b lactamase producers. The top four frequently isolated bacteria are Micrococcus species (16%), Staphylococcus haemolyticus (13.2%), Staphylococcus aureus (10%), and Klebsiella pneumoniae (10%). Twenty two bacterial species were subjected to antimicrobial susceptibility testing by using broad and narrow spectrum antibiotics and antimicrobials. Ampicillin showed the lowest susceptibility rate against Gram positives, followed by erythromycin and azithromycin. The lesser antimicrobial susceptibility potential among Gram negative bacteria was exhibited against ampicillin, followed by piperacillin and cefotaxime.ConclusionOur findings emphasize the importance of highlighting urine bacterial flora in research especially those related to susceptibility patterns, employing more advanced culture methods as multiple drug resistant bacteria were isolated.

scholarly journals Comparing BioFire FilmArray BCID2 and BCID panels for direct detection of bacterial pathogens and antimicrobial resistance genes from positive blood cultures

2021 ◽  
Author(s):  
Venere Cortazzo ◽  
Tiziana D’Inzeo ◽  
Liliana Giordano ◽  
Giulia Menchinelli ◽  
Flora Marzia Liotti ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Yeast Species ◽  
Bacterial Species ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Antimicrobial Resistance Genes

Among molecular assays currently developed for detection and identification of pathogens (and their antimicrobial resistance genes) in positive blood cultures (BCs) (1), the BioFire FilmArray blood culture identification (BCID) panel (bioMérieux, Marcy l’Étoile, France)—a multiplex PCR assay with less than 2 minutes of hands-on time and a ∼1-hour turnaround time—allows syndromic diagnosis of bloodstream infection (BSI) (2, 3). Previously, the panel could identify 24 etiological agents of BSI (11 Gram-negative bacteria, 8 Gram-positive bacteria, and 5 yeast species), as well as three antimicrobial resistance genes (mecA, vanA/B, and blaKPC, which encodes Klebsiella pneumoniae carbapenemase). Now, the BioFire FilmArray BCID2 panel encompasses 43 molecular targets associated with BSI, including 15 Gram-negative bacteria, 11 Gram-positive bacteria, 7 yeast species, and 10 antimicrobial resistance genes (https://www.biomerieux-diagnostics.com/biofire-bcid-panel). The last targets include genes encoding for carbapenemases (IMP, KPC, OXA-48-like, NDM, and VIM), colistin resistance (mcr-1), ESBL (CTX-M), methicillin-resistance (mecA/C and, specifically for methicillin-resistant Staphylococcus aureus [MRSA], mecA/C and MREJ [mec right-extremity junction]), or vancomycin resistance (vanA/B). Unlike BCID, no published studies to date reported on the BCID2 performance. This study evaluated and compared the accuracy of BCID2 with that of BCID to identify bacterial species and relative antimicrobial resistance genes directly from positive BCs.

Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

1992 ◽  
Vol 50 (1) ◽  
pp. 686-687
Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara
Keyword(s):  
Chronic Arthritis ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Infectious Arthritis ◽  
Bacterial Arthritis ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.

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