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Journal of Medical Microbiology Jun 2024The absence of a gold-standard methodology for the microbiological diagnosis of urinary tract infections (UTI) has led to insufficient standardization of criteria for...
The absence of a gold-standard methodology for the microbiological diagnosis of urinary tract infections (UTI) has led to insufficient standardization of criteria for the interpretation of results and processing methods, particularly incubation time and culture media. 48-hour incubation time period and use of blood agar enhances the sensitivity of microorganisms isolated significantly. To determine the sensitivity of blood agar and Brilliance UTI chromogenic agar, incubating for different periods (24-48 hours), for the detection of positive urine cultures. Comparisons were made between all possible combinations of media and incubation times. As the gold-standard reference, we used the routine methodology of our laboratory, which involves prior screening with available clinical data, flow cytometry, sediment analysis and/or Gram staining. Screened samples were then cultured on blood agar and chromogenic agar and incubated for 48 hours. Also, based on the results of Gram staining, additional media were added in selected cases. The most significant difference was found between chromogenic agar incubated for 24 hours and blood agar incubated for 48 hours, with the latter method allowing the recovery of 10.14 % more microorganisms ( < 0.0001). Furthermore, the value of performing Gram staining to guide processing was demonstrated, as it avoided the loss of at least 5.14 % of isolates. At least in urological and nephrological patients it is essential to include enriched culture media (blood agar) or to extend the incubation times due to the improvement of the diagnostic sensitivity of urine cultures. Gram staining also can help detect the presence of fastidious microorganisms or mixed infections, indicating whether rich and/or selective media should be included to enhance the diagnostic sensitivity of cultures. If this methodology is not followed, it should be noted that besides fastidious species, fastidious strains of and will also be missed.
Topics: Urinary Tract Infections; Humans; Culture Media; Time Factors; Sensitivity and Specificity; Bacteriological Techniques; Bacteria; Agar; Urine
PubMed: 38935081
DOI: 10.1099/jmm.0.001846 -
Antibiotics (Basel, Switzerland) Jun 2024The emergence and spread of antimicrobial resistance (AMR) among Enterobacteriaceae pose significant threats to global public health. In this study, we conducted a...
Genomic Characterization of Multidrug-Resistant Enterobacteriaceae Clinical Isolates from Southern Thailand Hospitals: Unraveling Antimicrobial Resistance and Virulence Mechanisms.
The emergence and spread of antimicrobial resistance (AMR) among Enterobacteriaceae pose significant threats to global public health. In this study, we conducted a short-term surveillance effort in Southern Thailand hospitals to characterize the genomic diversity, AMR profiles, and virulence factors of Enterobacteriaceae strains. We identified 241 carbapenem-resistant Enterobacteriaceae, of which 12 were selected for whole-genome sequencing (WGS) and genome analysis. The strains included , , , , , , , , spp., and . The strains exhibited high levels of multidrug resistance, including resistance to carbapenem antibiotics. Whole-genome sequencing revealed a diverse array of antimicrobial resistance genes (ARGs), with strains carrying genes for ß-lactamase, efflux pumps, and resistance to other antibiotic classes. Additionally, stress response, metal tolerance, and virulence-associated genes were identified, highlighting the adaptability and pathogenic potential of these strains. A plasmid analysis identified several plasmid replicons, including IncA/C2, IncFIB(K), and Col440I, as well as several plasmids identical to those found globally, indicating the potential for the horizontal gene transfer of ARGs. Importantly, this study also identified a novel species of spp. PSU27, adding to the understanding of the genetic diversity and resistance mechanisms of Enterobacteriaceae in Southern Thailand. The results reported in this study highlight the critical importance of implementing effective antimicrobial management programs and developing innovative treatment approaches to urgently tackle AMR.
PubMed: 38927197
DOI: 10.3390/antibiotics13060531 -
Antibiotics (Basel, Switzerland) May 2024Antibiotic resistance (AMR) is a major public health concern. Antimicrobial peptides (AMPs) could be an alternative to conventional antibiotics. The purpose of this...
Antibiotic resistance (AMR) is a major public health concern. Antimicrobial peptides (AMPs) could be an alternative to conventional antibiotics. The purpose of this research was to investigate the antimicrobial ability of the synthetic AMPs (i.e., A-11 and AP19) on the most frequently isolated bacteria in boar semen and their effect on extended boar semen quality during storage. We tested the antimicrobial effect of A-11 and AP19 at different concentrations and compared them with gentamicin for inhibiting the growth of E. coli, Pseudomonas aeruginosa and Proteus mirabilis that were isolated from fresh boar semen. In order to evaluate the effect of AMP on semen qualities on days 0, 1, 3, and 5 after storage at 18 °C, seven fresh boar semen samples were collected, diluted with semen extender with antibiotic (i.e., gentamicin at 200 µg/mL, positive control) or without (negative control), and semen extender contained only A-11 or AP19 at different concentrations (i.e., 62.50, 31.25, and 15.625 µg/mL). The total bacterial count was also measured at 0, 24, 36, 48, and 72 h after storage. Comparable to gentamicin, both A-11 and AP19 inhibited the growth of E. coli, Pseudomonas aeruginosa, and Proteus mirabilis at 62.50, 31.25, and 15.625 µg/mL, respectively. Comparing the total bacterial count at 0, 24, 36, 48 and 72 h after storage, the lowest total bacterial concentration was found in the positive control group ( < 0.05), and an inferior total bacterial concentration was found in the treatment groups than in the negative control. On day 1, there is a lower percentage of all sperm parameters in the AP19 group at a concentration of 62.50 µg/mL compared with the other groups. On day 3, the highest percentage of all sperm parameters was found in the positive control and A-11 at a concentration of 31.25 µg/mL compared with the other groups. The AP19 group at 62.5 µg/mL constantly yielded inferior sperm parameters. On day 5, only A-11 at a concentration of 15.625 µg/mL showed a total motility higher than 70%, which is comparable to the positive control. A-11 and AP19 showed antimicrobial activity against , and isolated from boar semen. Considering their effect on semen quality during storage, these antimicrobial peptides are an alternative to conventional antibiotics used in boar semen extenders. Nevertheless, the utilization of these particular antimicrobial peptides relied on the concentration and duration of storage.
PubMed: 38927156
DOI: 10.3390/antibiotics13060489 -
Bioscience, Biotechnology, and... Jun 2024Virulence pathways in pathogenic bacteria are regulated by quorum sensing mechanisms, particularly biofilm formation through autoinducer production and sensing. In this...
Virulence pathways in pathogenic bacteria are regulated by quorum sensing mechanisms, particularly biofilm formation through autoinducer production and sensing. In this study, the culture filtrate extracted from an edible mushroom, Agaricus subrutilescens, was fractionated to isolate a compound that inhibits biofilm formation. Four gram-negative bacteria (Klebsiella pneumoniae, Escherichia coli, Proteus mirabilis, and Enterobacter cloacae) and two gram-positive bacteria (Enterococcus faecalis and Staphylococcus aureus) were used for the bioassay. The bioassay-guided chromatographic separations of the culture filtrate extract resulted in the isolation of the compound. Further, spectroscopic analyses revealed the identity of the compound as 2,2'-azoxybisbenzyl alcohol (ABA). The minimum inhibitory and sub-inhibitory concentrations of the compound were also determined. ABA was significantly effective in inhibiting biofilm formation in all tested bacteria, with half-maximal inhibitory concentrations of 3-11 µg/mL. Additionally, the bioactivity of ABA was confirmed through the bioassays for the inhibition of exopolysaccharide matrixes and autoinducer activities.
PubMed: 38925646
DOI: 10.1093/bbb/zbae089 -
Protein Expression and Purification Jun 2024Lectins are versatile proteins that specifically recognize and interact with sugar moieties expressed on the cell surface. The potential of lectin in drug targeting and...
Lectins are versatile proteins that specifically recognize and interact with sugar moieties expressed on the cell surface. The potential of lectin in drug targeting and delivery has instigated interest to identify natural lectins. Crabs have been identified as a rich source of lectin because the innate immune system is activated on encounter of pathogens and helps in the production of lectin. Although the presence of lectins in crab's hemolymph is well documented, little information about lectin in hepatopancreas, a vital organ for immunity and digestion in crustaceans, is currently available. A calcium dependent lectin (75 kDa) was purified from the hepatopancreas of the freshwater crab Oziotelphusa naga by bioadsorption and fetuin linked Sepharose 4B affinity chromatography technique. The isolated hepatopancreas lectin is calcium dependent and maximum agglutination was observed with rabbit erythrocytes. The hemagglutinating activity of the hepatopancreas lectin was effectively inhibited by sugars, such as α-lactose, GlcNAc, trehalose and NeuAc. Compared to sialylated N-glycosylated proteins including transferrin and apo transferrin, sialylated O-glycosylated proteins like fetuin exhibited stronger inhibitory effect. The ability of erythrocytes to bind hepatopancreas lectin has been diminished by desialylation of the potent inhibitor, indicating the significance of sialic acid in lectin-ligand interactions. The purified hepatopancreas lectin showed a broad spectrum of antimicrobial activity against bacteria Staphylococcus aureus, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, E. coli and fungi Candida albicans and Aspergillus niger. The findings of this study demonstrate the significance of hepatopancreas lectin as a multifunctional defense protein that inhibits the growth of bacteria and fungi.
PubMed: 38908458
DOI: 10.1016/j.pep.2024.106536 -
International Journal of Molecular... Jun 2024Overuse of antimicrobials has greatly contributed to the increase in the emergence of multidrug-resistant bacteria, a situation that hinders the control and treatment of...
Overuse of antimicrobials has greatly contributed to the increase in the emergence of multidrug-resistant bacteria, a situation that hinders the control and treatment of infectious diseases. This is the case with urinary tract infections (UTIs), which represent a substantial percentage of worldwide public health problems, thus the need to look for alternatives for their control and treatment. Previous studies have shown the usefulness of autologous bacterial lysates as an alternative for the treatment and control of UTIs. However, a limitation is the high cost of producing individual immunogens. At the same time, an important aspect of vaccines is their immunogenic amplitude, which is the reason why they must be constituted of diverse antigenic components. In the case of UTIs, the etiology of the disease is associated with different bacteria, and even , the main causal agent of the disease, is made up of several antigenic variants. In this work, we present results on the study of a bacterial lysate composed of 10 serotypes of and by , , , , , and . The safety of the compound was tested on cells in culture and in an animal model, and its immunogenic capacity by analysing in vitro human and murine macrophages (cell line J774 A1). The results show that the polyvalent lysate did not cause damage to the cells in culture or alterations in the animal model used. The immunostimulatory activity assay showed that it activates the secretion of TNF-α and IL-6 in human macrophages and TNF-α in murine cells. The obtained results suggest that the polyvalent lysate evaluated can be an alternative for the treatment and control of chronic urinary tract infections, which will reduce the use of antimicrobials.
Topics: Urinary Tract Infections; Animals; Humans; Mice; Escherichia coli; Female; Cell Extracts; Bacterial Lysates
PubMed: 38892345
DOI: 10.3390/ijms25116157 -
BMC Microbiology Jun 2024This study aims to conduct an in-depth genomic analysis of a carbapenem-resistant Proteus mirabilis strain to uncover the distribution and mechanisms of its resistance...
OBJECTIVE
This study aims to conduct an in-depth genomic analysis of a carbapenem-resistant Proteus mirabilis strain to uncover the distribution and mechanisms of its resistance genes.
METHODS
The research primarily utilized whole-genome sequencing to analyze the genome of the Proteus mirabilis strain. Additionally, antibiotic susceptibility tests were conducted to evaluate the strain's sensitivity to various antibiotics, and related case information was collected to analyze the clinical distribution characteristics of the resistant strain.
RESULTS
Study on bacterial strain WF3430 from a tetanus and pneumonia patient reveals resistance to multiple antibiotics due to extensive use. Whole-genome sequencing exposes a 4,045,480 bp chromosome carrying 29 antibiotic resistance genes. Two multidrug-resistant (MDR) gene regions, resembling Tn6577 and Tn6589, were identified (MDR Region 1: 64.83 Kb, MDR Region 2: 85.64 Kbp). These regions, consist of integrative and conjugative elements (ICE) structures, highlight the intricate multidrug resistance in clinical settings.
CONCLUSION
This study found that a CR-PMI strain exhibits a unique mechanism for acquiring antimicrobial resistance genes, such as bla, located on the chromosome instead of plasmids. According to the results, there is increasing complexity in the mechanisms of horizontal transmission of resistance, necessitating a comprehensive understanding and implementation of targeted control measures in both hospital and community settings.
Topics: Proteus mirabilis; beta-Lactamases; Humans; Drug Resistance, Multiple, Bacterial; Anti-Bacterial Agents; Microbial Sensitivity Tests; Proteus Infections; Whole Genome Sequencing; Bacterial Proteins; Chromosomes, Bacterial; Genome, Bacterial; Carbapenems
PubMed: 38890647
DOI: 10.1186/s12866-024-03365-7 -
Indian Journal of Otolaryngology and... Jun 2024Chronic Otitis Media is characterized by distinct bacteriology compared with Acute Otitis Media, with COM being highly likely to harbor multiple bacteria of anaerobic...
Chronic Otitis Media is characterized by distinct bacteriology compared with Acute Otitis Media, with COM being highly likely to harbor multiple bacteria of anaerobic and aerobic types of organisms (Cameron and Hussam K. El-Kashlan, xxx). In some patients, chronic infection with otorrhea will persist despite aggressive medical therapy. With the large number of cases of COM which presents to Sanjay Gandhi Memorial Hospital, and a majority being resistant to the common medications, we decided to undertake this study to have a better understanding of the bacterial epidemiology, the resistance, and what antibiotic to use in such cases. To determine the prevalence of different bacteriological agents and their antibiotic sensitivity pattern in patients of Chronic Otitis Media-Active Mucosal Disease presenting to ENT OPD at Sanjay Gandhi Memorial Hospital, Mangolpuri, Delhi. An observational cross-sectional study of 200 patients. After an initial examination, two sterile cotton swab sticks were introduced to collect pus samples from the medial part of the external auditory canal. The swabs were sent to the microbiology lab for Gram Staining, Culture, and Biochemical Tests, for identification of the different bacteriological agents and their antibiotic sensitivity patterns. Most common organism seen was Pseudomonas aeruginosa, followed by , mixed bacterial growth, and Candida spp. If regular monitoring of bacteriological profile is done in each hospital, this will help us to choose the antibiotics in a better manner and hence prevent the appearance of newer resistant strains.
PubMed: 38883512
DOI: 10.1007/s12070-024-04573-3 -
Current Computer-aided Drug Design Jun 2024Marine sediment bacteria have been generating considerable attention lately due to their potential as valuable reservoirs of novel antimicrobial agents.
The Antibacterial Efficacy of a Compound Extracted from Marine Sediment Bacterium Enterococcus Lactis (S-2): A Comparative Analysis Through In-Vitro and In-Silico Assessments.
BACKGROUND
Marine sediment bacteria have been generating considerable attention lately due to their potential as valuable reservoirs of novel antimicrobial agents.
AIM
In vitro and in silico antibacterial activities of antibacterial compounds isolated from the marine sediment bacterium Enterococcus Lactis (S-2).
METHODS
Coastal sediment samples were collected from Rameswaram, Ramnathapuram District, Tamil Nadu, India. Bacteria were isolated using the crowded plate method, and their phenotypic and genotypic characteristics were studied. Purified bacteria were cultured in large volumes, secondary metabolites were extracted, and novel antibacterial agents were isolated from the aqueous extract. Novel compound antibacterial activity was studied through in-silico and invitro. The mechanism activity of antibacterial activity was confirmed by a high-resolution transmission electron microscope.
RESULTS
Genotypic analysis confirmed that the isolated S-2 bacteria were Enterococcus lactis, and the aqueous extract showed antibacterial activity against Staphylococcus aureus (17 mm zone of inhibition) and Proteus mirabilis (12 mm zone of inhibition). A bioactive molecule, 13- hydroxy-9-(1-hydroxyethyl)-11-methoxy-2,4dioxapentacyclo[10.7.1.0³,⁴.0⁵,²¹.0¹³,¹⁶]icosa- 1(20),5,7,12,14(19), 16-hexane-18-one, was isolated from aqueous extracts of the S-2 bacterium. Chromatography and spectroscopic analysis confirmed the identity of the isolated compound. Novel compound potential antibacterial activity showing against S. aureus (18 mm zone of inhibition) and MIC 250 μg/mL, which was confirmed by tetrazolium staining. The antibacterial activity mechanism was confirmed by transmission electron microscopy. Molecular docking studies show good binding (-9.9 kcal/mol) of the compound with 3U2D, while molecular dynamic simulation studies confirm the conformationally stable structure of the complex between 3U2D and 13-hydroxy-9-(1-hydroxyethyl)-11-methoxy-2,4-dioxapentacyclo [10.7.1.0³,⁴.0⁵,²¹.0¹³,¹⁶]icosa-1(20),5,7,12,14(19), 16-hexane-18-one. It has been observed from the docking study of 3U2D with standard drug ciprofloxacin that the lower affinity is compared to the test ligand, which has a docking score of 7.3 kcal/mol. Out of interacting residues of protein 3U2D residue, Thr173 and Ile86 formed conventional hydrogen bonds.
CONCLUSION
Marine bacterium E. lactis produces a novel antibacterial compound (13-hydroxy- 9-(1-hydroxyethyl)-11-methoxy-2,4-dioxapentacyclo[10.7.1.0³,⁴.0⁵,²¹.0¹³,¹⁶]icosa- 1(20),5,7,12,14(19),16-hexane-18-one), which shows antibacterial activity against clinical S. aureus, confirmed by in vitro and in silico analysis. This molecule can used as a lead molecule for antibacterial activity.
PubMed: 38867524
DOI: 10.2174/0115734099305519240531053135 -
Zeitschrift Fur Naturforschung. C,... Jun 2024is a traditional medicinal plant used to treat hypertension, diarrhea and urinary disorders. Silica gel chromatographic separation of CHCl/MeOH (1:1) roots extract of...
is a traditional medicinal plant used to treat hypertension, diarrhea and urinary disorders. Silica gel chromatographic separation of CHCl/MeOH (1:1) roots extract of afforded seven compounds namely; β-sitosterol (), stigmasterol (), 6a, 12a-dehydro-deguelin (), tephrosin (), maackiain (), obovatin () and 6-oxo, 6a, 12a-dehydro-deguelin (). GC-MS analysis of essential oils from the root of displayed a total of 17 compounds of which cis-nerolidol (41.7 %) and cadinol (19.7 %) were the major constituents. CHCl/MeOH (1:1) extract, MeOH extract, maackiain () and obovatin () showed moderate inhibitory activity against with MIC value of 0.5, 0.66, 0.83 and 0.83 mg/mL, respectively, compared to ciprofloxacin (MIC of 0.078 μg/mL). 6a, 12a-dihydro-deguelin (), and 6-oxo, 6a, 12a-dehydro-deguelin () displayed significant activity against with MIC values of 0.66 mg/mL. Tephrosin () and maackiain () also showed moderate antibacterial activity against and with MIC values of 0.83 and 0.5 mg/mL, respectively, compared to ciprofloxacin (0.312 μg/mL). The radical scavenging activity results indicated that tephrosin (), obovatin () and 6-oxo, 6a, 12a-dehydro-deguelin () showed potent DPPH scavenging activity with IC values of 10.97, 10.43 and 10.73 μg/mL, respectively, compared to ascorbic acid (IC of 5.83 μg/mL). The docking prediction results revealed that 6a, 12a-dehydro-deguelin () displayed the best binding energy of -8.1 kcal/mol towards pyruvate kinase of (PDB ID: 3T07) and -7.9 kcal/mol towards urease (PDB ID: 1E9Y) and DNA gyrase B of (PDB: 4F86) receptors compared to ciprofloxacin (-7.2 to -8.0 kcal/mol). Maackiain () and obovatin () displayed the minimum binding energy of -7.9 and -8.2 kcal/mol towards the LasR protein of (PDB: ID 2UV) and FtsZ (PDB: ID 4M8I), respectively. The SwissADME drug-likeness and Pro Tox II toxicity prediction results indicated that compounds (-) obeyed Lipinski's rule of five with 0 violations and none of them were found to be hepatotoxic, mutagenic, and cytotoxic, respectively. The assessment results supported by the in silico analysis revealed that crude extracts and isolated compounds showed promising antibacterial and antioxidant activity, which proves the therapeutic potential of the roots of .
PubMed: 38865441
DOI: 10.1515/znc-2024-0044