Read by QxMD icon Read


Changsheng Guo, Kai Wang, Song Hou, Li Wan, Jiapei Lv, Yuan Zhang, Xiaodong Qu, Shuyi Chen, Jian Xu
Inactivating antibiotic resistant bacteria (ARB) and removing antibiotic resistance genes (ARGs) are very important to prevent their spread into the environment. Previous efforts have been taken to eliminate ARB and ARGs from aqueous solution and sludges, however, few satisfying results have been obtained. This study investigated whether photocatalysis by TiO2 was able to reduce the two ARGs, mecA and ampC, within the host ARB, methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, respectively...
October 19, 2016: Journal of Hazardous Materials
Ketrin Cristina da Silva, Marcos Paulo Vieira Cunha, Louise Cerdeira, Maria Gabriela Xavier de Oliveira, Mirela Caroline Vilela de Oliveira, Cleise Ribeiro Gomes, Nilton Lincopan, Terezinha Knöbl, Andrea Micke Moreno
This study reports the high-virulence phylogenetic backgrounds of CMY-2- and CTX-M-2-producing avian pathogenic Escherichia coli strains isolated from turkeys sent to slaughter and condemned by airsacculitis in Brazil. Among 300 air sac samples, seven E. coli strains produced plasmid-mediated CMY-2-type AmpC, of which three carried also the blaCTX-M-2 Extended Spectrum Beta-Lactamase encoding gene. Interestingly, the transfer of the blaCMY-2 gene was positive for three E. coli strains, being associated with the presence of IncI1 plasmids...
October 7, 2016: Diagnostic Microbiology and Infectious Disease
Farah Ben Tanfous, Carla Andrea Alonso, Wafa Achour, Laura Ruiz-Ripa, Carmen Torres, Assia Ben Hassen
The aim of this study was to investigate the molecular features among Klebsiella pneumoniae and Escherichia coli strains showing a resistant/intermediate-resistant phenotype to ertapenem (R/IR-ERT), implicated in colonization/infection in patients of the Hematology and Graft Units of the National Bone Marrow Transplant Center of Tunisia (3-year period, 2011-2014). The major carbapenemase, extended-spectrum beta-lactamase, and plasmidic AmpC beta-lactamase genes were analyzed and characterized by PCR and sequencing...
October 18, 2016: Microbial Drug Resistance: MDR: Mechanisms, Epidemiology, and Disease
Santosh Kumar Singh, Seema Kumari, Minakshi Gupta
Escherichia coli mediated urinary tract infection has been reported to be most prevalent among patients of different class, gender and ages. Currently, multidrug resistant E. coli harboring several virulence factors are most perilous threats for patients especially for elders. The aim of this study was to determine the antibiotic resistance pattern, co-resistance and phenotypic virulence factors present in uropathogenic E. coli isolates from aged patients. Thirty-nine E. coli isolates were collected during May-June 2014 from patients aged 50-80 years...
October 12, 2016: Microbial Pathogenesis
Robert A Bonomo
β-Lactamases, the enzymes that hydrolyze β-lactam antibiotics, remain the greatest threat to the usage of these agents. In this review, the mechanism of hydrolysis is discussed for both those enzymes that use serine at the active site and those that require divalent zinc ions for hydrolysis. The β-lactamases now include >2000 unique, naturally occurring amino acid sequences. Some of the clinically most important of these are the class A penicillinases, the extended-spectrum β-lactamases (ESBLs), the AmpC cephalosporinases, and the carbapenem-hydrolyzing enzymes in both the serine and metalloenzyme groups...
October 14, 2016: Cold Spring Harbor Perspectives in Medicine
Gabriel Cabot, Carla López-Causapé, Alain A Ocampo-Sosa, Lea M Sommer, María Ángeles Domínguez, Laura Zamorano, Carlos Juan, Fe Tubau, Cristina Rodríguez, Bartolomé Moyà, Carmen Peña, Luis Martínez-Martínez, Patrick Plesiat, Antonio Oliver
Whole genome sequencing (WGS) was used for the characterization of the, frequently extensively-drug resistant (XDR), P. aeruginosa high-risk clone ST175. A total of eighteen ST175 isolates recovered from 8 different Spanish hospitals were analyzed; four isolates from four different French hospitals were included for comparison. The typical resistance profile of ST175 included penicillins, cephalosporins, monobactams, carbapenems, aminoglycosides, and fluoroquinolones. In the phylogenetic analysis, the four French isolates clustered together with the two isolates from one of the Spanish regions...
October 10, 2016: Antimicrobial Agents and Chemotherapy
Jing Yu, Kun Tan, Zhihui Rong, Yue Wang, Zhongju Chen, Xuhui Zhu, Li Wu, Li Tan, Wei Xiong, Ziyong Sun, Ling Chen
BACKGROUND: The spread of resistance to carbapenems among Enterobacteriaceae has become a major public health problem in recent years. In this study, we describe an outbreak of Klebsiella pneumoniae in the neonatal ward. First, we aimed to study the drug resistance, genetic relatedness, and transmission mechanism of carbapenem-resistant K. pneumoniae; second, we implemented infection control measures to contain the outbreak. METHODS: We investigated 27 non-repetitive strains isolated from neonates and five strains cultured from around the neonatal ward...
October 12, 2016: BMC Infectious Diseases
Cristian Gustavo Aguilera Rossi, Paulino Gómez-Puertas, Juan Alfonso Ayala Serrano
BACKGROUND: Community and nosocomial infections by Pseudomonas aeruginosa still create a major therapeutic challenge. The resistance of this opportunist pathogen to β-lactam antibiotics is determined mainly by production of the inactivating enzyme AmpC, a class C cephalosporinase with a regulation system more complex than those found in members of the Enterobacteriaceae family. This regulatory system also participates directly in peptidoglycan turnover and recycling. One of the regulatory mechanisms for AmpC expression, recently identified in clinical isolates, is the inactivation of LMM-PBP4 (Low-Molecular-Mass Penicillin-Binding Protein 4), a protein whose catalytic activity on natural substrates has remained uncharacterized until now...
October 6, 2016: BMC Microbiology
Mazen S Bader, Mark Loeb, Annie A Brooks
Urinary tract infections (UTIs) caused by antibiotic-resistant Gram-negative bacteria are a growing concern due to limited therapeutic options. Gram-negative bacteria, specifically Enterobacteriaceae, are common causes of both community-acquired and hospital acquired UTIs. These organisms can acquire genes that encode for multiple antibiotic resistance mechanisms, including extended-spectrum-lactamases (ESBLs), AmpC- β -lactamase, and carbapenemases. The assessment of suspected UTI includes identification of characteristic symptoms or signs, urinalysis, dipstick or microscopic tests, and urine culture if indicated...
October 7, 2016: Postgraduate Medicine
C Katvoravutthichai, K Boonbumrung, R Tiyawisutsri
Pseudomonas aeruginosa is one of the most important causes of nosocomial infection and it has increasing resistance to many antimicrobial agents. β-lactamase production is the most frequent mechanism for β-lactam resistance in P. aeruginosa. We evaluated the prevalence of β-lactamase genes in P. aeruginosa for classes A, C, and D by polymerase chain reaction, and investigated clonal diversity by pulsed-field gel electrophoresis (PFGE). We used the disk diffusion method to test 118 non-duplicate clinical isolates of P...
September 23, 2016: Genetics and Molecular Research: GMR
Anamariela Tijerino Ayala, Hilda María Bolaños Acuña, María Teresa Acuña Calvo, José Luis Vargas Morales, Elena Campos Chacón
Plasmid-mediated AmpC are enzymes belonging to the group of β-lactamases and encoded by bla AmpC genes. Of these enzymes, those known as type CMY-2 are the most frequently reported worldwide. Detection of enterobacteria that produce CMY-2-type plasmid-mediated AmpC is clinically important since the use of β-lactam antibiotics can result in treatment failure. It is also important from a public health standpoint owing to the capacity for conjugative plasmid transfer to other enterobacteria, both within the community and in nosocomial environments...
August 2016: Revista Panamericana de Salud Pública, Pan American Journal of Public Health
Marion J Skalweit, Mei Li
Genetic screening of Pseudomonas aeruginosa (PSDA) and Acinetobacter baumannii (ACB) reveals genes that confer increased susceptibility to β-lactams when disrupted, suggesting novel drug targets. One such target is lytic transglycosylase. Bulgecin A (BlgA) is a natural product of Pseudomonas mesoacidophila and a lytic transglycosolase inhibitor that works synergistically with β-lactams targeting PBP3 for Enterobacteriaceae. BlgA also weakly inhibits di-Zn(2+) metallo-β-lactamases like L1 of Stenotrophomonas maltophilia...
2016: Drug Design, Development and Therapy
Shio-Shin Jean, Po-Ren Hsueh
OBJECTIVES: To investigate the antimicrobial resistance and assess the molecular characteristics of β-lactamases (ESBLs, AmpC β-lactamases and carbapenemases) among Enterobacteriaceae isolates that caused intra-abdominal infections (IAIs) in patients hospitalized in the Asia-Pacific region during 2008-14. METHODS: Multiplex PCR was used to detect the specific types of β-lactamase in 2893 isolates with MICs of ertapenem >0.5 mg/L. In-hospital acquisition times for most isolates were also delineated...
October 4, 2016: Journal of Antimicrobial Chemotherapy
Judith A Anesi, Ebbing Lautenbach, Irving Nachamkin, Charles Garrigan, Warren B Bilker, Mary Wheeler, Pam Tolomeo, Jennifer H Han
OBJECTIVE To evaluate risk factors for and molecular characteristics of community-onset extended-spectrum cephalosporin-resistant (ESC-R) Enterobacteriaceae (EB) urinary tract infections (UTIs) in a US health system. DESIGN Case-control study. PARTICIPANTS All patients presenting to the emergency department or outpatient practices with EB UTIs from December 21, 2010, through April 22, 2013, were included. Case patients had ESC-R EB UTIs. Control patients had ESC-susceptible EB UTIs and were matched 1:1 on study year...
September 28, 2016: Infection Control and Hospital Epidemiology
Baharak Babouee Flury, Matthew J Ellington, Katie L Hopkins, Jane F Turton, Michel Doumith, Neil Woodford
Mechanisms leading to carbapenem and cephalosporin resistance were sought in Enterobacter aerogenes isolates that were highly resistant to carbapenems but had no known carbapenemase. Results were compared with recent work examining carbapenem-resistant Enterobacter cloacae. Eighteen carbapenem-resistant E. aerogenes were screened for known β-lactamase and carbapenemase genes, and novel carbapenemases were sought in whole-genome sequencing (WGS) data of the three most resistant isolates. For all isolates, ampC, ampR, ampD and the porin genes omp35 and omp36 were investigated by Sanger sequencing or from available WGS data...
September 12, 2016: International Journal of Antimicrobial Agents
Tatsuya Nakayama, Michio Jinnai, Ryuji Kawahara, Khong Thi Diep, Nguyen Nam Thang, Tran Thi Hoa, Le Kieu Hanh, Pham Ngoc Khai, Yoshinori Sumimura, Yoshimasa Yamamoto
Reports of livestock infections with extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-E) are increasing. Based on interviews conducted over a 6-month period, we found that veterinarians in the Vietnamese province of Thai Binh prefer to prescribe colistin-based drugs (CBD) in chicken farms. We aimed to clarify whether CBD use selects for strains of colistin-resistant ESBL-E. With the cooperation of seven local households, we detected ESBL-E in chickens' feces after treating chickens with CBD...
September 23, 2016: Tropical Animal Health and Production
Clara Atterby, Andrew M Ramey, Gabriel Gustafsson Hall, Josef Järhult, Stefan Börjesson, Jonas Bonnedahl
BACKGROUND: Antibiotic-resistant bacteria pose challenges to healthcare delivery systems globally; however, limited information is available regarding the prevalence and spread of such bacteria in the environment. The aim of this study was to compare the prevalence of antibiotic-resistant bacteria in large-bodied gulls (Larus spp.) at urban and remote locations in Southcentral Alaska to gain inference into the association between antibiotic resistance in wildlife and anthropogenically influenced habitats...
2016: Infection Ecology & Epidemiology
Shamshul Ansari, Rabindra Dhital, Sony Shrestha, Sangita Thapa, Ram Puri, Niraj Chaudhary, Suresh Khatiwada, Rajendra Gautam
Introduction. Pseudomonas aeruginosa is the most frequently isolated organism as it acts as the opportunistic pathogen and can cause infections in immunosuppressed patients. The production of different types of beta-lactamases renders this organism resistant to many commonly used antimicrobials. Therefore, the aim of this study was to document the antibiotic resistance rate in Pseudomonas aeruginosa isolated from different clinical specimens. Methods. Pseudomonas aeruginosa recovered was identified by standard microbiological methods...
2016: BioMed Research International
M A Gonggrijp, I M G A Santman-Berends, A E Heuvelink, G J Buter, G van Schaik, J J Hage, T J G M Lam
A cross-sectional study was conducted to evaluate the prevalence of extended-spectrum β-lactamase (ESBL)- and plasmid-mediated AmpC-producing Escherichia coli and associated risk factors in dairy herds. One hundred dairy herds were randomly selected and sampled to study the presence of ESBL- and AmpC-producing E. coli in slurry samples. The sensitivity of testing slurry samples for ESBL/AmpC herd status is less than 100%, especially for detecting herds with a low ESBL/AmpC prevalence. Therefore, whereas herds that tested positive for ESBL/AmpC-producing E...
September 13, 2016: Journal of Dairy Science
Jacopo Sgrignani, Filomena De Luca, Hayarpi Torosyan, Jean-Denis Docquier, Da Duan, Beatrice Novati, Fabio Prati, Giorgio Colombo, Giovanni Grazioso
β-Lactamases are bacterial enzymes conferring resistance to β-lactam antibiotics in clinically-relevant pathogens, and represent relevant drug targets. Recently, the identification of new boronic acids (i.e. RPX7009) paved the way to the clinical application of these molecules as potential drugs. Here, we screened in silico a library of ~1400 boronic acids as potential AmpC β-lactamase inhibitors. Six of the most promising candidates were evaluated in biochemical assays leading to the identification of potent inhibitors of clinically-relevant β-lactamases like AmpC, KPC-2 and CTX-M-15...
September 8, 2016: Journal of Computer-aided Molecular Design
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"