scholarly journals Promoter Variation and Gene Expression of mcr-1 -Harboring Plasmids in Clinical Isolates of Escherichia coli and Klebsiella pneumoniae from a Chinese Hospital

2018 ◽  
Vol 62 (5) ◽  
Author(s):  
Bin Huang ◽  
Yuting He ◽  
Xingyan Ma ◽  
Renxin Cai ◽  
Jianming Zeng ◽  
...  
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Tertiary Care ◽  
Care Hospital ◽  
Content Type ◽  
Sequence Variations ◽  
Generation Sequencing ◽  
Gene Expression Levels

ABSTRACT Next-generation sequencing of 6 mcr-1 -harboring Escherichia coli and Klebsiella pneumoniae isolates collected from a tertiary care hospital in China revealed significant sequence variations in the regions flanking the mcr-1 gene. While sequence variations significantly affected the expression and promoter activity of mcr-1 , the mcr-1 gene expression levels did not correlate with the in vitro colistin resistance levels, which warrants further in-depth investigations.

scholarly journals Differential Gene Expression of Three Mastitis-Causing Escherichia coli Strains Grown under Planktonic, Swimming, and Swarming Culture Conditions

mSystems ◽  
2016 ◽  
Vol 1 (4) ◽  
Author(s):  
John D. Lippolis ◽  
Brian W. Brunelle ◽  
Timothy A. Reinhardt ◽  
Randy E. Sacco ◽  
Tyler C. Thacker ◽  
...  
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Bacterial Motility ◽  
Differentially Expressed ◽  
Iron Regulation ◽  
Content Type ◽  
E Coli ◽  
Different Types ◽  
Compare Gene Expression ◽  
Gene Expression Levels

ABSTRACT Bacteria can exhibit various types of motility. It is known that different types of motilities can be associated with virulence. In this work, we compare gene expression levels in bacteria that were grown under conditions that promoted three different types of E. coli motility. Better understanding of the mechanisms of how bacteria can cause an infection is an important first step to better diagnostics and therapeutics. Bacterial motility is thought to play an important role in virulence. We have previously shown that proficient bacterial swimming and swarming in vitro is correlated with the persistent intramammary infection phenotype observed in cattle. However, little is known about the gene regulation differences important for different motility phenotypes in Escherichia coli. In this work, three E. coli strains that cause persistent bovine mastitis infections were grown in three media that promote different types of motility (planktonic, swimming, and swarming). Using whole-transcriptome RNA sequencing, we identified a total of 935 genes (~21% of the total genome) that were differentially expressed in comparisons of the various motility-promoting conditions. We found that approximately 7% of the differentially expressed genes were associated with iron regulation. We show that motility assays using iron or iron chelators confirmed the importance of iron regulation to the observed motility phenotypes. Because of the observation that E. coli strains that cause persistent infections are more motile, we contend that better understanding of the genes that are differentially expressed due to the type of motility will yield important information about how bacteria can become established within a host. Elucidating the mechanisms that regulate bacterial motility may provide new approaches in the development of intervention strategies as well as facilitate the discovery of novel diagnostics and therapeutics. IMPORTANCE Bacteria can exhibit various types of motility. It is known that different types of motilities can be associated with virulence. In this work, we compare gene expression levels in bacteria that were grown under conditions that promoted three different types of E. coli motility. Better understanding of the mechanisms of how bacteria can cause an infection is an important first step to better diagnostics and therapeutics.

scholarly journals In VitroandIn VivoActivities of OP0595, a New Diazabicyclooctane, against CTX-M-15-Positive Escherichia coli and KPC-Positive Klebsiella pneumoniae

2016 ◽  
Vol 60 (5) ◽  
pp. 3001-3006 ◽  
Author(s):  
Akihiro Morinaka ◽  
Yuko Tsutsumi ◽  
Keiko Yamada ◽  
Yoshihiro Takayama ◽  
Shiro Sakakibara ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Infection Model ◽  
Gram Negative Bacteria ◽  
Content Type ◽  
Effective Combination ◽  
Time Kill ◽  
Lactamase Inhibitor

ABSTRACTGram-negative bacteria are evolving to produce β-lactamases of increasing diversity that challenge antimicrobial chemotherapy. OP0595 is a new diazabicyclooctane serine β-lactamase inhibitor which acts also as an antibiotic and as a β-lactamase-independent β-lactam “enhancer” againstEnterobacteriaceae. Here we determined the optimal concentration of OP0595 in combination with piperacillin, cefepime, and meropenem, in addition to the antibacterial activity of OP0595 alone and in combination with cefepime, inin vitrotime-kill studies and anin vivoinfection model against five strains of CTX-M-15-positiveEscherichia coliand five strains of KPC-positiveKlebsiella pneumoniae. An OP0595 concentration of 4 μg/ml was found to be sufficient for an effective combination with all three β-lactam agents. In bothin vitrotime-kill studies and anin vivomodel of infection, cefepime-OP0595 showed stronger efficacy than cefepime alone against all β-lactamase-positive strains tested, whereas OP0595 alone showed weaker or no efficacy. Taken together, these data indicate that combinational use of OP0595 and a β-lactam agent is important to exert the antimicrobial functions of OP0595.

scholarly journals Epidemiology and microbiology of Gram-negative bloodstream infections in a tertiary-care hospital in Beijing, China: a 9 -year retrospective study

2020 ◽  
Author(s):  
Zhixin Liang ◽  
Qiang Zhu ◽  
Minghui Zhu ◽  
Chunyan Li ◽  
Lina Li ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Acinetobacter Baumannii ◽  
Tertiary Care Hospital ◽  
Tertiary Care ◽  
Bloodstream Infections ◽  
Care Hospital ◽  
Gram Negative ◽  
Resistance Rates ◽  
Beijing China

Abstract Background Gram-negative bacterial bloodstream infections (BSIs) are serious diseases associated with high morbidity and mortality. The following study examines the incidence, clinical characteristics and microbiological features, drug resistance situations and mortality associated with gram-negative BSIs at a large Chinese tertiary-care hospital in Beijing, China. Methods A retrospective cohort study of patients with gram-negative BSIs was performed between January 1, 2010, and December 31, 2018, at the Chinese People's Liberation Army General Hospital. The patients’ data were collected and included in the reviewing electronic medical records. Results A total of 6867 episodes of gram-negative BSIs occurred among 3199 patients over 9 years, and there were 3032 significant BSI episodes 77% of these cases were healthcare-associated, while 23% were community-associated. The overall incidence of gram-negative BSIs fluctuated from 2.30 to 2.55 episodes per 1000 admissions over 9 years. Malignancy was the most common comorbidity and indwelling central intravenous catheter was the most common predisposing factor for gram-negative BSI. Escherichia coli were the major pathogen (34.3%), followed by Klebsiella pneumoniae (23.3%) and other bacterial pathogens (9.9%). The resistance rates of Escherichia coli and Klebsiella pneumoniae to penicillins were more than 90%. and the resistance rates of Acinetobacter baumannii to the most antibiotic were more than 70% include the Carbapenem. The resistance of ESBLs-producing Escherichia coli to the most antibiotic was higher than non-ESBLs producing Escherichia coli but to Carbapenems(0.7% VS 5.1%). The rates of Carbapenems resistance of ESBLs-producing Klebsiella pneumoniae and non-ESBLs producing Klebsiella pneumoniae were 32.8% and 8.1%. The rates of Carbapenems resistance of Enterobacter cloacae and Pseudomonas aeruginosa were 1.4% and 27.8% respectively. Between 2010 and 2018, the overall mortality of gram-negative BSIs decreased from 11.41–9.05%(X2 = 6.95, P = 0.434). Moreover, the mortality in the ICU decreased from 27.03–14.93%(X2 = 9.61, P = 0.212), while in the general ward fluctuated from 8.85–8.13% that without obvious decrease change(X2 = 9.29, P = 0.232). Conclusions The mortality of gram-negative BSIs have showed downward trends. carbapenem antibiotics is still consider the best treatment for patients with Gram-negative BSIs except Acinetobacter baumannii.

scholarly journals Incidence and sensitivity pattern of Klebsiella pneumoniae, Escherichia coli and Pseudomonas aeruginosa in a tertiary care hospital

2017 ◽  
Vol 6 (2) ◽  
pp. 329
Author(s):  
Anubhuti Khare ◽  
Saroj Kothari ◽  
Vaibhav Misra
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Tertiary Care ◽  
Care Hospital ◽  
E Coli ◽  
Medical College ◽  
Stewardship Program ◽  
Sensitivity Pattern ◽  
Indoor And Outdoor

Background: Antimicrobial resistance is a serious problem worldwide and differs from region to region. This study was planned to determine the incidence and sensitivity pattern of Klebsiella pneumoniae (K. pneumoniae), Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) in our region and discuss the general issues related to antimicrobial resistance.Methods: Prospective study was carried out between March to October 2015. Samples of urine, blood, pus, CSF and miscellaneous samples (fluids, swabs, sputum and stool) were collected from indoor and outdoor patients for isolation and antimicrobial susceptibility of K. pneumoniae, E. coli and P. aeruginosa in the Department of Microbiology G.R. Medical College, Gwalior (MP).Results: Out of the 5000 samples analyzed 1684 showed growth. K. pneumoniae (38.50%), E. coli (33.29%) and P. aeruginosa (28.19%) constituited a total of 805 isolates. Both E.coli and K. pneumoniae showed highest sensitivity for doxycycline (75%; 67% resp.) and second highest for levofloxacin (70%; 64% resp.), whereas, P. aeruginosa showed highest 57% sensitivity for amikacin followed by 48% for levofloxacin. β-lactam antibiotics and aminoglycosides showed high mean resistance (K.pneumoniae-83%, E.coli-79%, P. aeruginosa-86.4%) and (K. pneumoniae-75%, E. coli-61%, P. aeruginosa-70%) resp.Conclusions: The data indicates high resistance among the gram-negative bacteria for β-lactam and aminoglycoside antibiotics. Increasing resistance to doxycycline and flouroquinolones for K. pneumoniae and E. coli and multidrug resistance to P. aeruginosa is a cause of concern in this region. Thus, there is a need to stop misuse of antibiotics with immediate effect and to implement a strong antimicrobial stewardship program.

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