scholarly journals Multidrug-resistant Staphylococcus cohnii and Staphylococcus urealyticus isolates from German dairy farms exhibit resistance to beta-lactam antibiotics and divergent penicillin-binding proteins

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tobias Lienen ◽  
Arne Schnitt ◽  
Jens Andre Hammerl ◽  
Stephen F. Marino ◽  
Sven Maurischat ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Gene Prediction ◽  
Dairy Farms ◽  
Multidrug Resistant ◽  
Amino Acid Sequences ◽  
Penicillin Binding Protein ◽  
Beta Lactam ◽  
Penicillin Binding Proteins ◽  
Antimicrobial Substances ◽  
Beta Lactam Antibiotics

AbstractNon-aureus staphylococci are commonly found on dairy farms. Two rarely investigated species are Staphylococcus (S.) cohnii and S. urealyticus. Since multidrug-resistant S. cohnii and S. urealyticus are known, they may serve as an antimicrobial resistance (AMR) gene reservoir for harmful staphylococcal species. In our study, nine S. cohnii and six S. urealyticus isolates from German dairy farms were analyzed by whole-genome sequencing and AMR testing. The isolates harbored various AMR genes (aadD1, str, mecA, dfrC/K, tetK/L, ermC, lnuA, fexA, fusF, fosB6, qacG/H) and exhibited non-wildtype phenotypes (resistances) against chloramphenicol, clindamycin, erythromycin, fusidic acid, rifampicin, streptomycin, tetracycline, tiamulin and trimethoprim. Although 14/15 isolates lacked the blaZ, mecA and mecC genes, they showed reduced susceptibility to a number of beta-lactam antibiotics including cefoxitin (MIC 4–8 mg/L) and penicillin (MIC 0.25–0.5 mg/L). The specificity of cefoxitin susceptibility testing for mecA or mecC gene prediction in S. cohnii and S. urealyticus seems to be low. A comparison with penicillin-binding protein (PBP) amino acid sequences of S. aureus showed identities of only 70–80% with regard to PBP1, PBP2 and PBP3. In conclusion, S. cohnii and S. urealyticus from selected German dairy farms show multiple resistances to antimicrobial substances and may carry unknown antimicrobial resistance determinants.

scholarly journals Characterization of Multidrug Resistant Extended-Spectrum Beta-Lactamase-ProducingEscherichia coliamong Uropathogens of Pediatrics in North of Iran

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Mohammad Sadegh Rezai ◽  
Ebrahim Salehifar ◽  
Alireza Rafiei ◽  
Taimour Langaee ◽  
Mohammadreza Rafati ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Multidrug Resistant ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Beta Lactam Antibiotics ◽  
Extended Spectrum ◽  
Extended Spectrum Beta Lactamases ◽  
North Of Iran

Escherichia coliremains as one of the most important bacteria causing infections in pediatrics and producing extended-spectrum beta-lactamases (ESBLs) making them resistant to beta-lactam antibiotics. In this study we aimed to genotype ESBL-producingE. coliisolates from pediatric patients for ESBL genes and determine their association with antimicrobial resistance. One hundred of theE. coliisolates were initially considered ESBL producing based on their MIC results. These isolates were then tested by polymerase chain reaction (PCR) for the presence or absence ofCTX,TEM,SHV,GES, andVEBbeta-lactamase genes. About 30.5% of isolatedE. coliwas ESBL-producing strain. TheTEMgene was the most prevalent (49%) followed bySHV(44%),CTX(28%),VEB(8%), andGES(0%) genes. The ESBL-producingE. coliisolates were susceptible to carbapenems (66%) and amikacin (58%) and showed high resistance to cefixime (99%), colistin (82%), and ciprofloxacin (76%). In conclusion, carbapenems were the most effective antibiotics against ESBl-producingE. coliin urinary tract infection in North of Iran. The most prevalent gene is the TEM-type, but the other resistant genes and their antimicrobial resistance are on the rise.

scholarly journals Target for bacteriostatic and bactericidal activities of beta-lactam antibiotics against Escherichia coli resides in different penicillin-binding proteins.

1995 ◽  
Vol 39 (4) ◽  
pp. 812-818 ◽  
Author(s):  
G Satta ◽  
G Cornaglia ◽  
A Mazzariol ◽  
G Golini ◽  
S Valisena ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Penicillin Binding Protein ◽  
Beta Lactam ◽  
Beta Lactams ◽  
Killing Effect ◽  
Penicillin Binding Proteins ◽  
Beta Lactam Antibiotics ◽  
Bactericidal Activities ◽  
The Given ◽  
The Relationship

The relationship between cell-killing kinetics and penicillin-binding protein (PBP) saturation has been evaluated in the permeability mutant Escherichia coli DC2 in which the antimicrobial activity of beta-lactams has been described as being directly related to the extent of saturation of the PBP target(s). Saturation of a single PBP by cefsulodin (PBP 1s), mecillinam (PBP 2), and aztreonam (PBP 3) resulted in a slow rate of killing (2.5-, 1.5-, and 0.8-log-unit decreases in the number of CFU per milliliter, respectively, in 6 h). Saturation of two of the three essential PBPs resulted in a marked increase in the rate of killing, which reached the maximum value when PBPs 1s and 2 were simultaneously saturated by a combination of cefsulodin and mecillinam (4.7-log-unit decrease in the number of CFU per milliliter in 6 h). Inactivation of all three essential PBPs by the combination of cefsulodin, mecillinam, and aztreonam further increased the killing kinetics (5.5-log-unit decrease in the number of CFU per milliliter), and this was not significantly changed upon additional saturation of the nonessential PBPs 5 and 6 by cefoxitin. Similar relationships between PBP saturation and killing kinetics were obtained with imipenem and meropenem at concentrations which inhibited only one PBP (PBP 2), only two PBPs (PBP 1s and 2), or all three essential PBPs. Saturation of one or more PBPs also resulted in a different rate of bacteriolysis, the highest rate being obtained by the cefsulodin-mecillinam combination and by 5 micrograms of either imipenem or meropenem per ml. All of these conditions caused saturation of PBP 2 and saturation or extensive binding of PBP 1s. However, none of these conditions caused determined the fastest possible rate of killing, which occurred only when all three essential PBPs were saturated. It was concluded that the actual killing effect of beta-lactams is reflected by killing rates that approach the fastest possible rate for the given microorganism and that the targets for the bactericidal activity are precisely those PBPs whose saturation or binding occurs under conditions.

scholarly journals Differential Effects of Penicillin Binding Protein Deletion on the Susceptibility of Enterococcus faecium to Cationic Peptide Antibiotics

2015 ◽  
Vol 59 (10) ◽  
pp. 6132-6139 ◽  
Author(s):  
George Sakoulas ◽  
Monika Kumaraswamy ◽  
Poochit Nonejuie ◽  
Brian J. Werth ◽  
Micahel J. Rybak ◽  
...  
Keyword(s):  
Enterococcus Faecium ◽  
Cumulative Effect ◽  
Human Neutrophils ◽  
Peptide Antibiotics ◽  
Penicillin Binding Protein ◽  
Beta Lactam ◽  
Content Type ◽  
Penicillin Binding Proteins ◽  
Beta Lactam Antibiotics ◽  
Knockout Mutants

ABSTRACTBeta-lactam antibiotics sensitizeEnterococcus faeciumto killing by endogenous antimicrobial peptides (AMPs) of the innate immune system and daptomycin through mechanisms yet to be elucidated. It has been speculated that beta-lactam inactivation of selectE. faeciumpenicillin binding proteins (PBPs) may play a pivotal role in this sensitization process. To characterize the specific PBP inactivation that may be responsible for these phenotypes, we utilized a previously characterized set ofE. faeciumPBP knockout mutants to determine the effects of such mutations on the activity of daptomycin and the AMP human cathelicidin (LL-37). Enhanced susceptibility to daptomycin was dependent more on a cumulative effect of multiple PBP deletions than on inactivation of any single specific PBP. Selective knockout of PBPZ renderedE. faeciummore vulnerable to killing by both recombinant LL-37 and human neutrophils, which produce the antimicrobial peptide in high quantities. Pharmacotherapy targeting multiple PBPs may be used as adjunctive therapy with daptomycin to treat difficultE. faeciuminfections.

scholarly journals Kinetic properties of the Bacillus licheniformis penicillin-binding proteins

1995 ◽  
Vol 309 (1) ◽  
pp. 49-53 ◽  
Author(s):  
S Lepage ◽  
M Galleni ◽  
B Lakaye ◽  
B Joris ◽  
I Thamm ◽  
...  
Keyword(s):  
Bacillus Licheniformis ◽  
Accurate Determination ◽  
Kinetic Properties ◽  
Penicillin Binding Protein ◽  
Beta Lactam ◽  
Intact Cells ◽  
Penicillin Binding Proteins ◽  
Beta Lactam Antibiotics ◽  
Main Target

In the analysis of the interactions between beta-lactam antibiotics and their target enzymes, it is often difficult to estimate the kinetic properties of the molecules which react rapidly with their targets and in consequence behave as the most efficient antibiotics. The combined utilization of fluorescein-labelled penicillins and of a new competition method has allowed an accurate determination of the high second-order rate constants characterizing the acylation of Bacillus licheniformis penicillin-binding protein 1 (PBP1) by penicillins and cephalosporins. Strategies were devised for measuring high acylation rates while avoiding titration effects. The method was also suitable for measuring the PBP kinetic parameters in intact cells. These results also confirmed that PBP1 is probably the main target of most beta-lactam antibiotics. Cephalexin, however, reacted faster with PBP3.

scholarly journals Evolution and resistance expression of MRSA. Evaluation of beta-lactam antibiotics against a set of isogenic strains with different types of phenotypic expression.

1995 ◽  
Vol 42 (4) ◽  
pp. 517-524 ◽  
Author(s):  
K Asada ◽  
Y Inaba ◽  
E Tateda-Suzuki ◽  
K Kuwahara-Arai ◽  
T Ito ◽  
...  
Keyword(s):  
Meca Gene ◽  
Phenotypic Expression ◽  
Aminoglycoside Antibiotic ◽  
Penicillin G ◽  
Binding Affinities ◽  
Penicillin Binding Protein ◽  
Beta Lactam ◽  
Beta Lactam Antibiotics ◽  
Mrsa Infection ◽  
Resistance Expression

Methicillin-resistant Staphylococcus aureus (MRSA) has two mechanisms of resistance to beta-lactam antibiotics; one is mediated by mecA gene expression, and the other by penicillinase production. It has been generally accepted in the clinical field that beta-lactam antibiotics are not the drugs of choice for MRSA infection. In this report, however, ampicillin and penicillin G were shown to have relatively good activity against MRSA if combined with a beta-lactamase inhibitor, sulbactam. These beta-lactam antibiotics were found to have relatively high binding affinities to PBP2', the mecA-encoded MRSA-specific penicillin-binding protein. The possible therapeutic application of sulbactam/ampicillin against MRSA infection in combination with arbekacin, an aminoglycoside antibiotic newly developed and introduced into clinical use in Japan, is discussed.

Molecular Detection of Carbapenem Resistant Gram Negative Bacterial Isolates from Dogs 

2021 ◽  
Author(s):  
Surya Sankar ◽  
Thresia . ◽  
Anu Bosewell ◽  
M. Mini
Keyword(s):  
Companion Animals ◽  
Multidrug Resistant ◽  
Beta Lactam ◽  
Gram Negative ◽  
Extended Spectrum Beta Lactamase ◽  
Beta Lactam Antibiotics ◽  
Carbapenem Resistant ◽  
Carbapenemase Gene ◽  
Line Of Therapy ◽  
Encoding Genes

Background: Carbapenems are beta-lactam antibiotics that are considered as the last line of therapy against multidrug resistant extended spectrum beta-lactamase. The resistance to carbapenems predominantly through carbapenemase is one of the most important emerging health problems worldwide in the therapy of clinical infections. The objective of the present study is to determine the presence of carbapenemase encoding genes among Gram- negative bacterial spp. associated with clinical infections in dogs. Methods: 30 Escherichia coli, 11 Klebsiella pneumoniae and three Pseudomonas aeruginosa isolated from urine, swabs from lesional skin and anterior vagina of dogs presented with different clinical ailments formed the samples for the study. Polymerase chain reaction was carried out to detect the presence of carbapenemase encoding genes viz., KPC, NDM, OXA, VIM and IMP among the isolates.Result: Out of the 44 Gram- negative isolates tested, 28 (76.3%) were positive for at least one tested carbapenemase gene. The highest frequency of carbapenemase recorded was for NDM followed by OXA-181, KPC, OXA-48 and VIM. Our study identified a high prevalence of carbapenemases among companion animals like dogs which could act as potential source of transmission of these resistance bacteria or their genomes to humans.

scholarly journals Evaluation of antimicrobial resistance, biofilm forming potential, and the presence of biofilm-related genes among clinical isolates of Pseudomonas aeruginosa

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Esmat Kamali ◽  
Ailar Jamali ◽  
Abdollah Ardebili ◽  
Freshteh Ezadi ◽  
Alireza Mohebbi
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Resistance ◽  
Multidrug Resistant ◽  
Infection Prevention And Control ◽  
Beta Lactam ◽  
Antimicrobial Susceptibility Pattern ◽  
Combination Strategies ◽  
High Standards ◽  
And Control ◽  
Genotypic Characteristics

Abstract Objectives Pseudomonas aeruginosa is known as a leading cause of nosocomial infections worldwide. Antimicrobial resistance and biofilm production, as two main virulence factors of P. aeruginosa, are responsible for the persistence of prolonged infections. In this study, antimicrobial susceptibility pattern and phenotypic and genotypic characteristics of biofilm of P. aeruginosa were investigated. Results A total of 80 clinical P. aeruginosa isolates were obtained. Isolates showed resistance to all antibiotics with a rate from 12.5% (n = 10) against amikacin and piperacillin/tazobactam to 23.75% (n = 19) to levofloxacin. Multidrug-resistant P. aeruginosa accounted for 20% (n = 16). 83.75% (n = 67) of isolates showed biofilm phenotype. All three biofilm-related genes were found simultaneously in 87.5% (n = 70) of P. aeruginosa and 13.5% (n = 10) of the isolates had none of the genes tested. From the results of the present study, combination therapy including an anti-pseudomonal beta-lactam (piperacillin/tazobactam or ceftazidime) and an aminoglycoside or carbapenems (imipenem, meropenem) with fluoroquinolones in conjunction with an aminoglycoside can be used against Pseudomonas infections. However, reasonable antimicrobial use and high standards of infection prevention and control are essential to prevent further development of antimicrobial resistance. Combination strategies based on the proper anti-pseudomonal antibiotics along with anti-biofilm agents can also be selected to eradicate biofilm-associated infections.

scholarly journals Multidrug-Resistant Streptococcus agalactiae Strains Found in Human and Fish with High Penicillin and Cefotaxime Non-Susceptibilities

2020 ◽  
Vol 8 (7) ◽  
pp. 1055
Author(s):  
Carmen Li ◽  
Dulmini Nanayakkara Sapugahawatte ◽  
Ying Yang ◽  
Kam Tak Wong ◽  
Norman Wai Sing Lo ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Streptococcus Agalactiae ◽  
Novel Mutation ◽  
Multidrug Resistant ◽  
Sequence Type ◽  
Healthcare Facilities ◽  
Surveillance Studies ◽  
Penicillin Binding Proteins ◽  
Antimicrobial Resistance Genes

Penicillin non-susceptible Streptococcus agalactiae (PEN-NS GBS) has been increasingly reported, with multidrug-resistant (MDR) GBS documented in Japan. Here we identified two PEN-NS GBS strains during our surveillance studies: one from a patient’s wound and the other from a tilapia. The patient’s GBS (H21) and fish GBS (F49) were serotyped and tested for antibiotic susceptibility. Whole-genome sequencing was performed to find the sequence type, antimicrobial resistance genes, and mutations in penicillin-binding proteins (PBPs) and fluoroquinolone (FQ) resistance genes. H21 and F49 belonged to ST651, serotype Ib, and ST7, serotype Ia, respectively. H21 showed PEN and cefotaxime minimum inhibitory concentrations (MICs) of 2.0 mg/L. F49 showed PEN MIC 0.5 mg/L. H21 was MDR with ermB, lnuB, tetS, ant6-Ia, sat4a, and aph3-III antimicrobial resistance genes observed. Alignment of PBPs showed the combination of PBP1B (A95D) and 2B mutations (V80A, S147A, S160A) in H21 and a novel mutation in F49 at N192S in PBP2B. Alignment of FQ-resistant determinants revealed mutation sites on gyrA, gyrB, and parC and E in H21. To our knowledge, this is the first report of GBS isolates with such high penicillin and cefotaxime MICs. This raises the concern of emergence of MDR and PEN-NS GBS in and beyond healthcare facilities.

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