• Food Science of Animal Resources
• /
• v.32 no.6
• /
• pp.713-717
• /
• 2012

The objective of this study was to evaluate the effect of sodium habituation on thermal resistance of Staphylococcus aureus in various ready-to-heat (RTH) sauces. The strain mixture of S. aureus strains KACC10768, KACC10778, KACC11596, KACC13236 and NCCP10862 was habituated up to 9% of NaCl. The inocula of NaCl-habituated and non-habituated S. aureus were inoculated in 5 g portions of pork cutlet, meat and Carbonara sauces at 7 Log CFU/g, and the samples were vortexed vigorously. The inoculated samples were then exposed to 60 and $70^{\circ}C$ in a water-bath, and survivals of total bacteria and S. aureus were enumerated on tryptic soy agar and mannitol salt agar, respectively, every 30 min for 120 min. At 60oC, the cell counts of total bacteria and the significant difference in survivals between sodium-habituated and non-habituated S. aureus were observed only in the Carbonara sauce; the tailing effect, which is the period of no reduction of bacterial cell counts, was observed in pork cutlet, meat and Carbonara sauces subjected to $60^{\circ}C$. At $70^{\circ}C$, total bacterial populations and sodium-habituated and non-habituated S. aureus cell counts in meat and Carbonara sauce also significantly decreased (p<0.05) after 30 min of heat treatment, followed by the obvious tailing effect. Sodium-habituated S. aureus cell counts in meat and Carbonara sauces were higher (p<0.05) than those of non-habituated S. aureus at $70^{\circ}C$. The results indicate that sodium habituation of S. aureus cells may increase the thermal resistance of the pathogen in RTH sauces; moreover, heating RTH sauces for a short time before serving may not sufficiently decrease the cell counts of S. aureus, particularly for sodium-habituated strain.

• Journal of Microbiology and Biotechnology
• /
• v.31 no.11
• /
• pp.1481-1489
• /
• 2021

Early and accurate detection of pathogens is important to improve clinical outcomes of bloodstream infections (BSI), especially in the case of drug-resistant pathogens. In this study, we aimed to develop a culture-independent digital PCR (dPCR) system for multiplex detection of major sepsis-causing gram-negative pathogens and antimicrobial resistance genes using plasma DNA from BSI patients. Our duplex dPCR system successfully detected nine targets (five bacteria-specific targets and four antimicrobial resistance genes) through five reactions within 3 hours. The minimum detection limit was 50 ag of bacterial DNA, suggesting that 1 CFU/ml of bacteria in the blood can be detected. To validate the clinical applicability, cell-free DNA samples from febrile patients were tested with our system and confirmed high consistency with conventional blood culture. This system can support early identification of some drug-resistant gram-negative pathogens, which can help improving treatment outcomes of BSI.

• Journal of Korean Academy of Nursing
• /
• v.41 no.6
• /
• pp.742-749
• /
• 2011

Purpose: This study was conducted to examine public level of knowledge and attitudes regarding antibiotic use and potential drug resistance. Methods: A cross-sectional face-to-face survey of 1,177 residents aged 18 or over was conducted in Korea. A quota sampling method was used. Results: Most respondents (70%) did not know that antibiotics are ineffective in treating coughs and colds. Two-thirds of the respondents were unaware of the conditions under which antibiotic resistance occurs, despite understanding the concept of resistance. Lower education level and older age were independently associated with inadequate knowledge. Lower education level, older age, inadequate knowledge and no exposure to the education campaign were independently associated with poor attitude. Conclusion: The results of this study demonstrate that the general public has misunderstandings and a lack of knowledge with regard to antibiotic use, despite a national educational campaign. However, the campaign may have had an effect on the public's attitudes towards antibiotics.

• Clinical and Experimental Pediatrics
• /
• v.51 no.10
• /
• pp.1031-1037
• /
• 2008

Macrolide antimicrobial agents including erythromycin, roxithromycin, clarithromycin, and azithromycin are commonly used in the treatment of respiratory tract infections in children. Newer macrolides that have structural modifications of older drug erythromycin show improved change in the spectrum of activity, dosing, and administration. However, recent studies reported that increasing use of macrolide antibiotics is the main force driving the development of macrolide resistance in streptococci. In particular, azithromycin use is more likely to select for macrolide resistance with Streptococcus pneumoniae than is clarithromycin use, a possible reflection of its much longer half life. Recently, erythromycin resistance rates of S. pneumoniae and Streptococcus pyogenes are rapidly increasing in Korea. Two main mechanisms of acquired macrolide resistance have been described, altered binding site on the bacterial ribosome encoded by the ermB gene and active macrolide efflux pump encoded by the mef gene. Relationship between the susceptibility of S. pneumoniae and the response to macrolides has been shown in studies of acute otitis media, but less clear in cases of pneumonia. This article reviews the spectrum of activity, pharmacokinetic properties, mechanisms of action and resistance, and clinical implication of resistance on the treatment of respiratory tract infections in children.

• Microbiology and Biotechnology Letters
• /
• v.40 no.3
• /
• pp.197-207
• /
• 2012

This study investigated the role of plasmids and their relationship with the multiple antibiotic resistance of 30 Vibrios sp. isolated from molluscs and crustaceans sampled from the Kerala coastal waters of India. The biochemical identification and antibiotic resistance profiles were determined, followed by the plasmid profiles, conjugation and transformation efficiencies. The results showed a considerable difference in the level of bacterial resistance to various antibiotics; while all 30 strains were found to be MAR Vibrios sp. and their resistance patterns varied. All the strains were resistant to amoxycillin, ampicillin and carbeniciliin. 87% were resistant to rifampicin; 74% to cefuroxime; 67 to streptomycin; 53% to norfloxacin and ciprofloxacin and 47% to furazolidone and nalidixic acid. In addition to their antibiotic resistance, the plasmid DNA of the MAR Vibrios strains isolated from the molluscs and crustaceans was also studied. Nine strains isolated from crustaceans and molluscs were found to harbor 1-3 plasmids with sizes varying from 5. 98 kb to 19. 36 kb. The average transformation efficiency was about $5{\times}10^{-8}$ and the conjugation efficiency varied from $2.1{\times}10^{-3}$ to $10^{-9}$. A further study of antibiotic resistance patterns may be useful to test the extent of drug resistance in seafoods and help to devise a nationwide antibiotic policy.

• Korean journal of applied entomology
• /
• v.16 no.4 s.33
• /
• pp.229-234
• /
• 1977

The experiments were carried out to investigate the selection effects on the drug resistance to Agrepto in Xanthomonas oryzae, the causal bacteria of rice bacterial leaf blight. The results obtained were as follows. 1, The Agrepto was stable at the heat treatment of $105^{\circ}C$ for 20 minutes, when the drug was added in the media. 2. The local isolates of the bacteria, 75-6 and 75-9, showed the different resistante reaction, when they were selected by the Agrepto contained media which concentrations of 10r9/m1 and 100ug/ml. 3. The individuals shelving high degree of resistance, which can grow on the media contained 10,000ug/m1 of Agrepto, could selected by the concentrations as low as 10ug/ml and 100ug/m1, in one generation. 4. The highly resistant isolates which selected by 3-stepwise selections such as 100ug/ml, 3,000ug/ml and 10,000/ml plots, showed nearly normal growth at the media contained 100ug/ml of Agrepto 5. When the isolate 75-9 was selected at the 100ug/m1 of concentration, showed various degrees of resistance, indicating that the isolate may be composed of resistance groups that lower than 500ug/ml, between 500-1,000ug/ml and 1,000-3,000ug/ml, to the Agrept.

• Korean Journal of Clinical Pharmacy
• /
• v.23 no.1
• /
• pp.20-25
• /
• 2013

Background & Objectives: Burn injury mortality and septic complication are frequent and well-known in burned pediatric patients. The overuse of antibiotics is the base for development of wound infection by resistant microorganisms as well as opportunist agents. Methods: We have carried out a study of the bacterial profile and antimicrobial resistance clinically important bacteria isolated from burn wound infections in children patients. The most common isolate from burn wound cultures was Pseudomonas aeruginosa (26.8%), followed by Staphylococcus aureus (25.4%), Acinetobacter baumannii (12.7%), coagulase negative staphylococcus (12.0%), Enterococcus faecium (7.7%), Escherichia coli (4.9%), Enterococcus faecalis (3.7%), Burkholderia cepacia (3.0%), Enterobacter cloacae (2.3%) and Klebsiella pneumonia (2.3%). Colistin was very significantly effective drug in gram negative organism, such as Pseudomonas aeruginosa and Acinetobacter baumannii. Results & Conclusion: The resistance rates were 65% and 98% to piperacillin, 63% and 97% to ceftazidime, 28% and 50% to levofloxacin. The most effective antibiotic in gram positive organism, such as Staphylococcus aureus, coagulase negative staphylococcus were moxifloxacin. The resistance rates were 83% and 64% to ciprofloxacin, 80% and 17% to clindamycin.

• Korean Journal of Veterinary Service
• /
• v.19 no.1
• /
• pp.46-54
• /
• 1996

This study was perfomed to examine the distribution of causative agent of piglets diarrhea in eastern Chonnam province from February 1994 to March 1995. The causative agents of diarrhea were examined by bacterial culture test, parasitological test and serological test against PED, TGE and Rota. The 35 isolated E. coli were tested for antibiotic sensitivity. The results obtained were as follows. 1. The incidence of 81 piglets with diarrhea was most prevalent as 39.5% in the age of 2 to 4 weeks, compare to 34.6% in the age of 5 to 8 weeks and 16.0% under 1 weeks and 9.9 % in the age of 9 to 11 weeks after birth. 2. The incidence of 81 piglets diarrhea showed bacterial diarrhea(75.3%), viral diarrhea (35.8%) and parasitological diarrhea(18.5%). When compared the isolation frequency of each etiological agent, enteropathogenic E. coli was most prevalent as 55.5% in bacterial diarrhea, rotavlrus enteritis as 18.5% in viral diarrhea and trichuriasis as 13.6% in parasitological diarrhea. 3. The complicated infection of piglets was most prevalent as 41.7% in rotavirus enteritis with enteropathogenic E coli in 24 complicated piglets diarrhea. 4. In antibiotic sensitivity test, isolates showed moderatly resistance to Tobramycin, Amikacin, Imipenem, Trimethoprim/Sulfamethoxazole, Gentamicin, Ampicillin but sensitivty to Ticarcillin/K. The 30 E. coli isolate showed multiple drug resistances in 3 different antibiotics.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.11
• /
• pp.1604-1608
• /
• 2000

Penicillin antibiotics such as penicillin G, ampicillin and amoxicillin have been widely used in the pig industry to control salmonellosis, bacterial pneumonia, and urinary tract infections. Extensive use of antibiotics in veterinary clinics has resulted in tissue residues and bacterial resistance. To prevent unwanted drug residues entering the human food chain, extensive control measures have been established by both government authorities and industries. The demands for reliable, simple, sensitive, rapid and low-cost methods for residue analysis of foods are increasing. In this study, we established a rapid prediction test for the detection of pigs with unacceptable tissue residues of penicillins. The recommended therapeutic doses of three penicillins, penillin G (withdrawal time, 7 days), ampicillin (withdrawal time, 7 days) and amoxicillin (withdrawal time, 14 days), were administered to three groups of 20 pigs each. Blood was sampled before drug administration and during the withdrawal period. The concentration of penicillins in plasma, determined by a semi-quantitative ELISA, were compared to that of internal standard, 4 ppb, which corresponded to the Maximum Residue Limit in milk. The absorbance ratio of internal standard to sample (B/Bs) was employed as an index to determine whether drug residues in pig tissues were negative or positive. That is, a B/Bs ratio less than 1 was considered residue positive, and larger than 1 negative. All 60 plasma samples from pigs were negative to three penicillins at pretreatment. Penicillin G could be detected in the plasma of the treated pigs until day 4 post-treatment and ampicillin until day 2, whereas amoxicillin could be detected until day 10 of its withdrawal period. The present study showed that the semi-quantitative ELISA could be easily adapted to detect residues of penicillin antibiotics (penicillin G, ampicillin and amoxicillin) in live pigs.

• Korean Journal of Clinical Laboratory Science
• /
• v.43 no.2
• /
• pp.68-74
• /
• 2011

Pseudomonas aeruginosa is an aerobic, Gram-negative, glucose-nonfermenting bacterium, which has emerged as a serious opportunistic pathogen. Recently, outbreaks of carbapenem resistant P. aeruginosa give rise to significant therapeutic challenges for treating nosocomial infections. The genes of metallo-${\beta}$-lactamase (MBL), a powerful carbapenemase, are carried as a part of the mobile gene cassettes inserted into integrons playing an important role in rapid dissemination of antibiotic resistance genes among bacterial isolates. In this study, we investigated the prevalence of integron in imipenem resistant P. aeruginosa isolates. A total of 61 consecutive, non-duplicate, and imipenem resistant P. aeruginosa strains were isolated from a university hospital in the Chungcheong province of Korea. We employed repetitive extragenic palindromic sequence-based PCR (rep-PCR) method for the selection of clonally different P. aerusinosa strains. PCR and DNA sequencing were conducted for the detection of integrons. Twenty-one clonally different P. aeruginosa strains were isolated. Only one (P28) of the strains harbored $bla_{VIM-2}$ that was found as gene cassettes in class 1 integrons. Four of 21 carbapenem resistant P. aeruginosa strains harbored class 1 integron containing aminoglycoside resistance determinant. All of the integrons detected in the study contained more than one resistance gene cassette, which can mediate resistance to multiple antibiotics. To prevent further spreading of the multi-drug resistant P. aeruginosa, conseguent monitoring and clinical polices are required.