scholarly journals Beta-lactamase induction and cell wall metabolism in Gram-negative bacteria

2013 ◽  
Vol 4 ◽  
Author(s):  
Ximin Zeng ◽  
Jun Lin
Keyword(s):  
Cell Wall ◽  
Gram Negative Bacteria ◽  
Beta Lactamase ◽  
Cell Wall Metabolism ◽  
Gram Negative

Extended Spectrum Beta Lactamase (ESBL), bla TEM,bla SHVand bla CTX-M,resistance genes in Community and Healthcare Associated Gram Negative Bacteria from Osun State, Nigeria

2020 ◽  
Vol 20 ◽  
Author(s):  
Ganiyat Shitta ◽  
Olufunmilola Makanjuola ◽  
Olusolabomi Adefioye ◽  
Olugbenga Adekunle Olowe
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Gram Negative Bacteria ◽  
Beta Lactamase ◽  
Multiple Antibiotic Resistance ◽  
Esbl Production ◽  
Gram Negative ◽  
Extended Spectrum Beta Lactamase ◽  
Healthcare Associated ◽  
Esbl Producers

Background: Extended Spectrum Beta Lactamase (ESBL) production in gram negative bacteria confers multiple antibiotic resistance, adversely affecting antimicrobial therapy in infected individuals. ESBLs result from mutations in β-lactamases encoded mainly by the bla TEM,bla SHVand bla CTX-Mgenes. The prevalence of ESBL producing bacteria has been on the increase globally especially its upsurge among isolates from community-acquired infections. Aim: To determine ESBL prevalence and identify ESBL genes among clinical isolates in Osun State, Nigeria. Material and Methods: A cross-sectional study was carried out from August 2016 –July 2017 in Osun State, Nigeria. Three hundred and sixty Gram negative bacteria recovered from clinical samples obtained from both community and healthcare associated infections were tested. They included147 Escherichia coli(40.8%), 116 Klebsiella spp(32.2%), 44 Pseudomo-nas aeruginosa(12.2%) and23 Proteus vulgaris (6.4%) isolates. Others were Acinetobacter baumannii, Serratia rubidae, Citrobacter spp, Enterobacter spp and Salmonella typhi. Disk diffusion antibiotic susceptibility testing was carried out, isolates were screened for ESBL production and confirmed using standard laboratory procedures. ESBLs resistance genes were identified by Polymerase Chain Reaction (PCR). Results: All isolates demonstrated multiple antibiotic resistance. Resistance to ampicillin, amoxicillin with clavulanate and erythromycin was 100%, whereas resistance to Imipenem was very low (5.0%). : Overall prevalence of ESBL producers was 41.4% with Klebsiellaspp as the highest ESBL producing Enterobacteriacaea. ESBL producers were more prevalent among the hospital pathogens than community pathogens, 58% vs 29.5% (p=0.003). ESBL genes were detected in all ESBL producers with the blaCTX-Mgene predominating (47.0%) followed by blaTEM(30.9%) and blaSHVgene was the least, 22.1%. The blaCTX-Mgene was also the most prevalent in the healthcare pathogens (62%) but it accounted for only 25% in those of community origin. Conclusion: A high prevalence of ESBL producing gram negative organisms occurs both in healthcare and in the community in our environment with the CTX-M variant predominating. Efforts to control spread of these pathogens should be addressed.

scholarly journals Clonal Clusters, Molecular Resistance Mechanisms and Virulence Factors of Gram-Negative Bacteria Isolated from Chronic Wounds in Ghana

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 339
Author(s):  
Denise Dekker ◽  
Frederik Pankok ◽  
Thorsten Thye ◽  
Stefan Taudien ◽  
Kwabena Oppong ◽  
...  
Keyword(s):  
Molecular Epidemiology ◽  
Virulence Factors ◽  
Iron Uptake ◽  
Chronic Wounds ◽  
Sub Saharan Africa ◽  
Gram Negative Bacteria ◽  
Beta Lactamase ◽  
Secretion Systems ◽  
Gram Negative ◽  
E Coli

Wound infections are common medical problems in sub-Saharan Africa but data on the molecular epidemiology are rare. Within this study we assessed the clonal lineages, resistance genes and virulence factors of Gram-negative bacteria isolated from Ghanaian patients with chronic wounds. From a previous study, 49 Pseudomonas aeruginosa, 21 Klebsiellapneumoniae complex members and 12 Escherichia coli were subjected to whole genome sequencing. Sequence analysis indicated high clonal diversity with only nine P. aeruginosa clusters comprising two strains each and one E. coli cluster comprising three strains with high phylogenetic relationship suggesting nosocomial transmission. Acquired beta-lactamase genes were observed in some isolates next to a broad spectrum of additional genetic resistance determinants. Phenotypical expression of extended-spectrum beta-lactamase activity in the Enterobacterales was associated with blaCTX-M-15 genes, which are frequent in Ghana. Frequently recorded virulence genes comprised genes related to invasion and iron-uptake in E. coli, genes related to adherence, iron-uptake, secretion systems and antiphagocytosis in P. aeruginosa and genes related to adherence, biofilm formation, immune evasion, iron-uptake and secretion systems in K. pneumonia complex. In summary, the study provides a piece in the puzzle of the molecular epidemiology of Gram-negative bacteria in chronic wounds in rural Ghana.

scholarly journals Gram-positive bacteria cell wall-derived lipoteichoic acid induces inflammatory alveolar bone loss through prostaglandin E production in osteoblasts

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tsukasa Tominari ◽  
Ayumi Sanada ◽  
Ryota Ichimaru ◽  
Chiho Matsumoto ◽  
Michiko Hirata ◽  
...  
Keyword(s):  
Cell Wall ◽  
Bone Loss ◽  
Alveolar Bone ◽  
Osteoclast Differentiation ◽  
Lipoteichoic Acid ◽  
Alveolar Bone Loss ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

AbstractPeriodontitis is an inflammatory disease associated with severe alveolar bone loss and is dominantly induced by lipopolysaccharide from Gram-negative bacteria; however, the role of Gram-positive bacteria in periodontal bone resorption remains unclear. In this study, we examined the effects of lipoteichoic acid (LTA), a major cell-wall factor of Gram-positive bacteria, on the progression of inflammatory alveolar bone loss in a model of periodontitis. In coculture of mouse primary osteoblasts and bone marrow cells, LTA induced osteoclast differentiation in a dose-dependent manner. LTA enhanced the production of PGE2 accompanying the upregulation of the mRNA expression of mPGES-1, COX-2 and RANKL in osteoblasts. The addition of indomethacin effectively blocked the LTA-induced osteoclast differentiation by suppressing the production of PGE2. Using ex vivo organ cultures of mouse alveolar bone, we found that LTA induced alveolar bone resorption and that this was suppressed by indomethacin. In an experimental model of periodontitis, LTA was locally injected into the mouse lower gingiva, and we clearly detected alveolar bone destruction using 3D-μCT. We herein demonstrate a new concept indicating that Gram-positive bacteria in addition to Gram-negative bacteria are associated with the progression of periodontal bone loss.

Prevalence and Antibiogram of Extended-Spectrum Beta-Lactamase Producing Gram-negative Bacteria Isolated from Septicemic Neonates in a Tertiary Care Hospital

KYAMC Journal ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 171-175
Author(s):  
Tania Rahman ◽  
Momtaz Begum ◽  
Sharmeen Sultana ◽  
SM Shamsuzzaman
Keyword(s):  
Antimicrobial Susceptibility ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Care Hospital ◽  
Beta Lactamase ◽  
Blood Samples ◽  
Gram Negative ◽  
Extended Spectrum Beta Lactamase ◽  
Extended Spectrum ◽  
Esbl Producers

Background: In recent years, Extended-spectrum beta-lactamase (ESBL) producing microorganisms have complicated treatment of infections due to resistance of ESBL producing strains to a wide range of antimicrobials. Objective: Target of this study was to determine the prevalence of ESBL producing gramnegative bacteria in neonatal sepsis cases and to reveal the antimicrobial susceptibility pattern of those isolated ESBL producers. Materials and Methods: This cross sectional study was carried out in Dhaka Medical College Hospital (DMCH) over a period of 12 months from January to December in 2016. Following isolation and identification of gram-negative bacteria from blood samples of suspected septicemic neonates, antimicrobial susceptibility test was performed by Kirby Bauer disk-diffusion method and ESBL producers were detected by Double Disk Synergy (DDS) test. Results: Among 52 Gram-negative bacteria isolated from 106 blood samples, 34.61% ESBL producers were detected and Enterobacter spp. (45%) was predominant followed by Klebsiella pneumoniae (33.33%). None of the ESBL producers was resistant to colistin and tigecycline. All ESBL producing Acinetobacter baumannii, 77.78% and 66.67% of ESBL producing Enterobacter spp and Klebsiella spp. respectively showed resistance to meropenem. All ESBL producers were resistant to piperacillintazobactam. Conclusion: Appropriate measures should be taken to prevent the spread of ESBL producing strains by combining strategies for infection prevention, control and rational use of antibiotics. KYAMC Journal Vol. 11, No.-4, January 2021, Page 171-175

scholarly journals General principles for the formation and proliferation of a wall-free (L-form) state in bacteria

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Romain Mercier ◽  
Yoshikazu Kawai ◽  
Jeff Errington
Keyword(s):  
Cell Wall ◽  
Molecular Biology ◽  
Gram Negative Bacteria ◽  
Systematic Analysis ◽  
Gram Negative ◽  
Membrane Blebbing ◽  
Precursor Synthesis ◽  
Peptidoglycan Cell Wall ◽  
Synthetic Cells ◽  
Opening Up

The peptidoglycan cell wall is a defining structural feature of the bacterial kingdom. Curiously, some bacteria have the ability to switch to a wall-free or ‘L-form’ state. Although known for decades, the general properties of L-forms are poorly understood, largely due to the lack of systematic analysis of L-forms in the molecular biology era. Here we show that inhibition of peptidoglycan precursor synthesis promotes the generation of L-forms from both Gram-positive and Gram-negative bacteria. We show that the L-forms generated have in common a mechanism of proliferation involving membrane blebbing and tubulation, which is dependent on an altered rate of membrane synthesis. Crucially, this mode of proliferation is independent of the essential FtsZ based division machinery. Our results suggest that the L-form mode of proliferation is conserved across the bacterial kingdom, reinforcing the idea that it could have been used in primitive cells, and opening up its use in the generation of synthetic cells.

scholarly journals Detection of Extended Spectrum Beta-lactamase (ESBL) Producing Gram Negative Bacteria from Clinical Specimens of Sir Salimullah Medical College and Mitford Hospital.

2017 ◽  
Vol 10 (1) ◽  
pp. 8-12
Author(s):  
Shikha Paul ◽  
Sanya Tahmina Jhora ◽  
Prashanta Prasun Dey ◽  
Bilkis Ara Begum
Keyword(s):  
Tertiary Care ◽  
Gram Negative Bacteria ◽  
Care Hospital ◽  
Beta Lactamase ◽  
Gram Negative ◽  
Clinical Specimens ◽  
Extended Spectrum Beta Lactamase ◽  
Medical College ◽  
Extended Spectrum ◽  
Esbl Producers

Detection of Extended spectrum beta lactamase (ESBL) enzyme producing bacteria in hospital settings is vital as ESBL genes are transmissible. This study was carried out to determine the distribution of ESBL producing gram negative isolates at a tertiary care hospital in Dhaka city which deals with the patients hailing from relatively low socioeconomic status.Onehundred and twenty four gram negative bacteria isolated from different clinical specimens from outpatient and inpatient departments of Sir Salimullah Medical College and Mitford Hospital (SSMC & MH) were tested for ESBL by E test ESBL method in the department of microbiology of Sir Salimullah medical college (SSMC) from March 2013 to August 2013.Out of 124 gram negative bacteria 69 (55.65%) were positive for ESBL. Among the ESBL producers, Esch.coli was the highest (46.38%) which was followed by Serratia spp (11.59%), Enterobacter spp (10.14%), Proteus spp, (8.70%), Acinetobacter spp.(7.24%) and Klebsiella spp.(5.79%). Out of 32 Esch.coli isolated from outpatient department, 10 (31.25%) were positive for ESBL. On the other hand out of 27 Esch. coli isolated from inpatient department, 22 (81.48%) were positive for ESBL. The difference was statistically significant (p<0.001).So the present study reveals that the distribution of ESBL producers is more among the hospitalized patients than the patients of the community.Bangladesh J Med Microbiol 2016; 10 (1): 8-12

Select Gram-negative Aerobic Bacteria

2012 ◽  
pp. 90-101
Author(s):  
David R. McNamara ◽  
Franklin R. Cockerill
Keyword(s):  
Cell Wall ◽  
Sepsis Syndrome ◽  
Vital Role ◽  
Klebsiella Pneumonia ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Neisseria Meningitides ◽  
A Cell ◽  
Normal Human ◽  
Specific Species

Gram-negative bacteria may be rod-shaped (bacilli), spherical (cocci), oval, helical, or filamentous. Cytoplasmic membrane is surrounded by a cell wall consisting of a peptidoglycan layer and an outer cell membrane. Gram-negative bacteria are widely distributed in the natural environment. They are commensals with many animals and play a vital role in normal human physiology as intestinal commensals. Gram-negative bacteria are the cause of various human illnesses. The gram-negative bacterial cell wall contains various lipopolysaccharide endotoxins. Endotoxins trigger intense inflammation and the sepsis syndrome during infection. Specific species of gram-negative bacteria such as Neisseria meningitides, Moraxella catarrhalis, Acinetobacter, Vibrio, Klebsiella pneumonia, Salmonella, Pseudomonas aeruginosa, and Haemophilus influenza are reviewed.

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