Segment-Based Peptide Design Reveals the Importance of N-Terminal High Cationicity for Antimicrobial Activity Against Gram-Negative Pathogens.

Host defense antimicrobial peptides (AMPs) are recognized candidates to develop a new generation of peptide antibiotics. While high hydrophobicity can be deployed in peptides for eliminating Gram-positive bacteria, high cationicity is usually observed in AMPs against Gram-negative pathogen. This study investigates how the sequence distribution of basic amino acids affects peptide activity.

Origami of KR-12 Designed Antimicrobial Peptides and Their Potential Applications.

This review describes the discovery, structure, activity, engineered constructs, and applications of KR-12, the smallest antibacterial peptide of human cathelicidin LL-37, the production of which can be induced under sunlight or by vitamin D. It is a moonlighting peptide that shows both antimicrobial and immune-regulatory effects. Compared to LL-37, KR-12 is extremely appealing due to its small size, lack of toxicity, and narrow-spectrum antimicrobial activity.

Enhanced Antimicrobial Screening Sensitivity Enabled the Identification of an Ultrashort Peptide KR-8 for Engineering of LL-37mini to Combat Drug-Resistant Pathogens.

Identification of novel antibiotics is of top importance because of the threat of antibiotic-resistant pathogens. Antimicrobial screening in Mueller-Hinton broth is frequently the first step in antimicrobial discovery. Although widely utilized, this medium is not ideal as it could mask activity of candidates such as human cathelicidin LL-37 against methicillin-resistant (MRSA).

Antimicrobial Resistance Profiles and Molecular Characteristics of Extended-Spectrum β-Lactamase-Producing Isolated from Healthy Cattle and Pigs in Korea.

Antimicrobial-resistant bacteria isolated from food animals pose a major health threat to the public on this planet. This study aimed to determine the susceptibility profiles of isolated from cattle and pig fecal samples and investigate the molecular characteristics of extended-spectrum β-lactamase (ESBL)-producing using gene identification, conjugation, and Southern blot approach. Overall 293 were recovered from cattle (120 isolates) and pigs (173 isolates) in 7 provinces of Korea during 2017-2018.

Hydrophobic diversification is the key to simultaneously increased antifungal activity and decreased cytotoxicity of two ab initio designed peptides.

The fact that some antimicrobial peptides have been utilized clinically and as food preservatives stimulated the efforts in search of new candidates. In our previous studies, we succeeded in designing potent peptides against methicillin-resistant Staphylococcus aureus (MRSA), severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2), and Ebola viruses based on the database filtering technology. The designed peptides were proved highly potent.

Antibiotic Resistance Profiles and Molecular Characteristics of -Carrying Serovar Enteritidis Isolates from Healthy and Diseased Chickens in Korea.

Extended-spectrum β-lactamase (ESBL)-producing serovar Enteritidis has emerged as a public health concern. The main objectives of this study were therefore to determine the antimicrobial susceptibility profiles of Enteritidis and to investigate the molecular characteristics of identified ESBL-producing isolates. In the study, 237 Enteritidis isolates (232 isolates from chickens, 4 from cattle, and 1 from a pig) were recovered from carcasses and fecal samples of healthy and diseased food animals between 2010 and 2017.

Realistic and critical review of the state of systemic antimicrobial peptides.

Antimicrobial peptide research remains active not only because of the growing antibiotic resistance problem but also our desire to understand the role of innate immune peptides in host defense. While numerous peptides are currently under active development for topical use, this article highlights peptides with systemic efficacy. The scaffolds of these peptides range from linear to cyclic forms.

Antimicrobial Resistance in Isolates from Healthy Food Animals in South Korea, 2010-2020.

Antimicrobial-resistant bacteria in food animals pose a major public health threat worldwide. In this study, we aimed to assess the antimicrobial resistance profiles and resistance trends of commensal Escherichia coli isolated from the feces of healthy cattle, pigs, and chickens in South Korea during 2010 and 2020. A total of 7237 E.

Imipenem Resistance Mediated by Gene in .

Treatment of infectious diseases caused by carbapenem-resistant is becoming a greater challenge. This study aimed to identify the imipenem resistance mechanism in isolated from a dog. Minimum Inhibitory Concentration (MIC) was determined by the broth microdilution method according to the Clinical and Laboratory Standards Institute recommendations.

Antimicrobial Resistance Profiles and Macrolide Resistance Mechanisms of Isolated from Pigs and Chickens.

We identified 1218   isolates from fecal and carcass samples of pigs ( = 643) and chickens ( = 575) between 2010 and 2018. About 99% of the isolates were resistant to at least one antimicrobial agent. The isolates exhibited high resistance rates (>75%) to ciprofloxacin, nalidixic acid, and tetracycline.

Nationwide Surveillance on Antimicrobial Resistance Profiles of and Isolated from Healthy Food Animals in South Korea, 2010 to 2019.

Intestinal commensal bacteria are considered good indicators for monitoring antimicrobial resistance. We investigated the antimicrobial resistance profiles and resistance trends of and isolated from food animals in Korea between 2010 and 2019. and isolated from chickens and pigs, respectively, presented a relatively high resistance rate to most of the tested antimicrobials.

Nationwide Surveillance on Antimicrobial Resistance Profiles of Isolated from Major Food Animal Carcasses in South Korea During 2010-2018.

Contamination of meat with antimicrobial-resistant bacteria represents a major public health threat worldwide. In this study, we determined the antimicrobial resistance profiles and resistance trends of isolated from major food animal carcasses (408 cattle, 1196 pig, and 1312 chicken carcass isolates) in Korea from 2010 to 2018. Approximately 75%, 92%, and 77% of cattle, pig, and chicken carcass isolates, respectively, were resistant to at least one antimicrobial agent.

Mobile Colistin Resistance Gene - Detected on an IncI2 Plasmid in Typhimurium Sequence Type 19 from a Healthy Pig in South Korea.

Colistin is considered the last resort for the treatment of multi-drug resistant Gram-negative bacterial infections. We studied colistin resistance and the gene carriage in isolates recovered from food animals in South Korea between 2010 and 2018. Colistin resistance was found in 277 isolates, predominantly in Enteritidis (57.

Detection of the Phenicol-Oxazolidinone Resistance Gene in and from Food-Producing Animals during 2008-2018 in Korea.

We aimed to investigate the presence of the phenicol-oxazolidinone resistance gene in linezolid-resistant enterococci from food-producing animals and analyze its molecular characteristics. We collected 3941 and 5088 isolates from all provinces of South Korea from 2008 to 2018. We found linezolid resistance in 0.

Short communication: First detection of Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus ST30 in raw milk taken from dairy cows with mastitis in South Korea.

We identified 199 Staphylococcus aureus isolates from quarter milk samples of 1,289 dairy cattle between 2014 and 2018. About 66% of the isolates were resistant to at least 1 antimicrobial agent; the highest rate of resistance was to penicillin, followed by resistance to ampicillin, erythromycin, and sulfadimethoxine. We obtained 30 methicillin-resistant S.

Emergence of -Mediated Linezolid Resistance in Isolated from Pig Carcasses.

Altogether, 2547 isolated from cattle ( = 382), pig ( = 1077), and chicken carcasses ( = 1088) during 2010-2017 were investigated for linezolid resistance and were further characterized using molecular methods. We identified linezolid resistance in only 2.3% of pig carcass isolates.

First Report of an Strain Carrying the Colistin Resistance Determinant from a Dog in South Korea.

We studied the presence of the mobile colistin resistance gene - in isolates recovered from fecal and urine samples of companion animals, that were collected from South Korea in 2018 and 2019. The - gene was detected in one colistin-resistant . isolated from a diarrheic dog.

Resistance profiling and molecular characterization of Staphylococcus aureus isolated from goats in Korea.

Staphylococcus aureus is among the most common zoonotic pathogens that cause foodborne illnesses worldwide. The main objectives of the current study were therefore to determine the antimicrobial susceptibility profiles of S. aureus isolated from goats in Korea and to investigate the molecular characteristics of identified methicillin-resistant S.

Emergence of in Diseased Pigs in South Korea.

We examined the prevalence and molecular characteristics of carrying colistin-resistant among cattle, pig, and chicken isolates in South Korea. Among a total of 185 colistin-resistant isolates determined in this study (47 from cattle, 90 from pigs, and 48 from chicken), PCR amplification detected - genes in 17 isolates predominantly from diseased pigs. The - genes were characterized as in 15 isolates and - in 2 isolates.

Nationwide surveillance on serotype distribution and antimicrobial resistance profiles of non-typhoidal Salmonella serovars isolated from food-producing animals in South Korea.

Food-producing animals are considered a leading source of human Salmonella infections in Korea. However, there is a lack of comprehensive and up-to-date data regarding the diversity and resistance profiles of Salmonella serotypes in these animals. Therefore, this study aimed to determine the distribution and antimicrobial resistance profiles of Salmonella serotypes isolated from cattle, pigs, and chickens in Korea between 2010 and 2018.

Resistance Profiling and Molecular Characterization of Extended-Spectrum/Plasmid-Mediated AmpC β-Lactamase-Producing Isolated from Healthy Broiler Chickens in South Korea.

We aimed to identify and characterize extended-spectrum β-lactamase (ESBL)-and/or plasmid-mediated AmpC β-lactamase (pAmpC)-producing isolated from healthy broiler chickens slaughtered for human consumption in Korea. A total of 332 isolates were identified from 339 cloacal swabs in 2019. More than 90% of the isolates were resistant to multiple antimicrobials.

Tylosin exposure reduces the susceptibility of Salmonella Typhimurium to florfenicol and tetracycline.

Background: Antibiotics exposure has been implicated in the emergence of bacterial strains that are resistant to structurally related or unrelated antibiotics. Tylosin is a macrolide antibiotic that has been administered to treat respiratory pathogenic bacteria in swine. Thus, this study was undertaken to evaluate the impact of exposure to a constant (3 μg/mL) and decreasing concentrations of tylosin on the susceptibility of Salmonella enterica serovar Typhimurium to various antibiotics.

Methyl gallate and tylosin synergistically reduce the membrane integrity and intracellular survival of Salmonella Typhimurium.

Nymphaea tetragona Georgi (Nymphaceae) is traditionally used in Asia for the treatment of diarrhea, dysentery and fever. The plant contains various active compounds, including methyl gallate (MG) which are reported to inhibit bacterial virulence mechanisms. This study aimed to evaluate the alterations on viability, membrane potential and integrity of Salmonella enterica Serovar Typhimurium exposed to MG in combination with Tylosin (Ty), which is relatively inactive against Gram-negative bacteria, but it is commonly used as a feed additive in livestock.