• The Journal of the Korean Society for Microbiology
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• v.22 no.1
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• pp.55-59
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• 1987

Salmonella typhi infection, which was the most frequent enteric infection in Korea, has been decreasing, while the infection of other serogroups of Salmonella has been increasing since the later part of 1970s. In 1986, the number of serogroup B isolated by us increased to 46, which corresponds 21.1% of all enteropathogenic bacteria isolated from stool specimens. Salmonella isolates resistant to antimicrobial agents were extremly rare in Korea, in the 1970s. However, 7 of 13 serogroup B isolates showed resistance to ampicillin or to chloramphenicol in 1984. Among the serogroup B isolates in 1986, 71.7% and 69.6% were resistant to ampicillin and to chloramphenicol respectively. The minimum inhibitory concentrations of ampicillin and chloramphenicol against these isolates were >$128\;{\mu}g/ml$ and $128\;{\mu}g/ml$ respectively.

• YAKHAK HOEJI
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• v.43 no.1
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• pp.128-130
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• 1999

In vitro activity of commonly used antimicrobial agents against several clinical isolates were studied. In the case of E. coli, the MICs at which 90% of the bacteria are inhibited of ampicillin, Unasyn, cefazoline, cefotaxim, carbenicillin, gentamicin and ofloxacin were 100<, 100, 25, 0.2, 100<, 3.13, and $12.5{\;}\mu\textrm{g}/m$ , respectively. In the case of K . pneumoniae, the MICs at which 90% of the bacteria are inhibited of ampicillin, Unasyn, crfazoline, cefotaxim, carbenicillin, gentamicin and ofloxacin were 100<, 12.5, 100<, 0.1, 100<, 1.6, and $0.4{\;}\mu\textrm{g}/m$ , respectively. In the case of Enterobacter sp, the MICs at which 90% of the bacteria are inhibited of ampicillin, Unasyn, cefazoline, cefotaxim, carbenicillin, gentamicin and ofloxacin were 100<, 100, 100<, 6.25, 100<, 100 and $1.57{\;}\mu\textrm{g}/m$ , respectively. In the case of Acinetobacter sp, the MICs at which 90% of the bacteria are inhibited of ampicillin, Unasyn, cefazoline, cefotaxim, carbenicillin, gentamicin and ofloxacin were 100<, 100<, 100<, 100<, 100< 100< and $50{\;}\mu\textrm{g}/m$ , respectively. In the case of Pseudomonas sp, the MICs at which 90% of the bacteria are inhibited of ampicillin, Unasyn, cefazoline, cefotaxim, carbenicillin, gentamicin and ofloxacin were 100<, 100<, 100<, 50, 100<, 25 and $25{\;}\mu\textrm{g}/m$, respectively. In the case of S. aureus, the MICs at which 90% of the bacteria are inhibited of ampicillin, Unasyn, cefazoline, cefotaxim, carbenicillin, gentamicin and ofloxacin were 50, 50, 100<, 100<, 50, 50, and $100{\;}\mu\textrm{g}/m$, respectively.

• Journal of Life Science
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• v.28 no.12
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• pp.1529-1535
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• 2018

The number of antibiotic-resistant bacteria is increasing rapidly while the discovery rate of new antibiotics is in decline. A systematic study is therefore necessary to investigate which bacteria are resistant to medically important antibiotics and how high that resistance is. To that end, this study aimed to analyze which bacteria demonstrated resistance to ampicillin, one of the currently most-widely used medical antibiotics. Water samples were collected from the Changwon-Cheon that runs through Changwon City and from the pond in front of the dormitory building at Changwon University. Hundreds of ampicillin-resistant colonies were obtained and 22 morphologically distinct examples were chosen for further study. These bacteria were identified by amplifying their 16S rRNA genes and comparing those sequences with data in GenBank. The bacteria was identified as belonging to 10 families, 12 genera, and 17 species, and all were able to grow in the presence of $50{\mu}g/ml$ ampicillin while seven showed growth at ampicillin concentrations as high as 1.5 mg/ml.

• Journal of Food Hygiene and Safety
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• v.28 no.3
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• pp.213-216
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• 2013

Antibiotic Detection Kit (Combination I), a lateral flow immunoassay (LFIA) developed for the detection of antibiotic residues in milk, was utilized for the analysis of antibiotic residues in the muscle tissue of olive flounder. After 60-min treatment by dipping in water dosed with ampicillin (200-g/ton water), the residue depletion of ampicillin was investigated in 25 cultured olive flounder (Paralichthys olivaceus). Muscles of fish were sampled on the 1st, 2nd, 3rd, 4th and 5th day after drug treatment. The concentration of ampicillin in the muscle was determined by LFIA. The absorbance ratio of the sample to the control blank (Bs/Bo) was employed as an index to determine the muscle residues in olive flounder. To investigate the recovery rate, standard solutions were added to muscle samples to give final concentrations in the muscle of 4 and 8 ng/ml. The recovery rates of all spiked samples were > 96% of the spiked value. Ampicillin was detected in the muscle of fish treated with the drug until the 2nd day of the withdrawal period. The present study showed that the LFIA can be easily adopted to predict ampicillin residues in tissue of farmed fishes.

• The Journal of the Korean Society for Microbiology
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• v.15 no.1
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• pp.33-38
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• 1980

Shigella remains to be an important enteric pathogen in this country for the moment. Moreover, since 1978, most of the isolates have become resistant to ampicillin and co-trimoxazole, which used to be the drugs of choice for shigellosis. Since a disc diffusion technique alone has been used in our routine susceptibility test, the minimum inhibitory concentrations(MIC) of both ampicillin and co-trimoxazole to Shigella have never been known. In order to determine these, 195 isolates were tested by an agar dilution method, all of which were isolated at Yonsei Medical Center during the period of June 1978 to July 1980. The following results were obtained. 1. Sixty cultures(29.7%) were susceptible to ampicillin, being the MIC of 8 ${\mu}g/ml$ or less and 53(27.2%) were susceptible to co-trimoxazole, being the MIC of TMP/SMZ 4/76 ${\mu}g/ml$ or less. S. flexneri type 2 was often resistant to both antimicrobic agents. 2. An increasing rate of resistant isolates was noted, particularly in the year of 1979. 3. Many isolates were resistant to both agents. Somewhat more cultures. were ampicillin susceptible and co-trimoxazole resistant than the other way around. It seems that the determination of species or even serotypes might be of help sometimes to select proper antimicrobic agent to control the infection. A routine antimicrobic susceptibility test of Shigella to both ampicillin and co-trimoxazole would be advisable for a better selection of chemotherapeutic agent.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.597-604
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• 2011

Using 108 strains of Vibrio parahaemolyticus isolated from seawater, we investigated ampicillin-resistance profiles and the genetic characterization of ${\beta}$-lactamase (VPA0477). All of the strains studied, except one strain, were resistant to ampicillin. However, the strain that was susceptible to ampicillin had the same ${\beta}$-lactamase gene as the ampicillin-resistant strains. We compared ${\beta}$-lactamase promoter region sequences among five strains, including both ampicillin-resistant and -susceptible strains. In the susceptible strain, a nucleotide at position -19 in the methionine initiation codon for ${\beta}$-lactamase was not present in the ampicillin-resistant strains. The genes in the region containing the gene VPA0477 were present in all of the tested strains, and LA-PCR analysis showed that the distance between VPA0474 and VPA0479 in all of the V. parahaemolyticus samples was precisely 5.7 kb. In V. parahaemolyticus ${\beta}$-lactamase, four important structural features that are conserved in Class A ${\beta}$-lactamases were present in the deduced amino acid sequences. Taken together, our study demonstrates that V. parahaemolyticus ${\beta}$-lactamase is included in the Class A ${\beta}$-lactamase group, and some nucleotides within the promoter region are of particular importance for ${\beta}$-lactamase activity.

• Journal of Veterinary Clinics
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• v.23 no.2
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• pp.164-168
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• 2006

The residue depletion of ampicillin was investigated in the olive flounder (Paralichthys olivaceus), rockfish (Sebastes schlegeli), and red sea bream (Pagrus major) after 5 days treatment with medicated feed at a dose of 100 mg/kg bw/day. Fishes were sampled for muscle on 1st, 2nd, 3rd, and 4th day after treatment. Ampicillin concentrations were determined by high performance liquid chromatography after SPE column extraction. The recovery rates of ampicillin in muscle samples ranged 94-98% and 83-88% for the concentration of 0.05 mg/kg and 0.1 mg/kg, respectively. Ampicillin concentrations detected on 1st day after treatment were 0.143, 0.138, and 0.187 mg/kg in the muscle of olive flounder, rockfish, and red sea bream, respectively. After a withdrawal of 3 days, muscle concentrations were 0.016, 0.012, and 0.021 mg/kg in the olive flounder, rockfish, and red sea bream, respectively. Ampicillin was not detectable in muscle samples on 4 days following withdrawal of the medicated feed. From results of the present study, a withdrawal period of ampicillin is proposed on 5 days after 5 days treatment with medicated feed at a dose of 100 mg/kg bw/day to avoid the presence of excessive residues of the edible muscles of olive flounder, rockfish, and red sea bream.

• Pediatric Infection and Vaccine
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• v.27 no.1
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• pp.45-52
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• 2020

Purpose: This pilot study aimed to evaluate the efficacy of high dose ampicillin-sulbactam and colistin combination therapy for ventilator-associated pneumonia (VAP) caused by carbapenem-resistant Acinetobacter baumannii (CRAB) in the pediatric intensive care unit of Pusan National University Children's Hospital. Methods: We retrospectively reviewed 17 pediatric patients with VAP caused by CRAB from June 2017 to August 2018. Ten (58.8%) patients were treated with high dose ampicillin-sulbactam and colistin combination therapy (combination therapy group), whereas 7 were treated with colistin only or with various combinations with or without colistin (other antibiotics group). Clinical and bacteriological outcomes were compared between the groups. Results: The mean duration of fever after antibiotic use was 1.30±1.70 days in the combination therapy group and 1.71±1.49 days in the other antibiotics group. The mean duration of days for negative conversion of endotracheal aspirate bacterial culture after antibiotic therapy was 3.40±1.71 days in the combination therapy group and 11.80±8.86 days in the other antibiotics group. The mortality rate within 30 days of antibiotic therapy was 1/10 (10%) in the combination therapy group and 3/7 (42.9%) in the other antibiotics group. Conclusions: High dose ampicillin-sulbactam and colistin combination therapy as early antibiotic treatment in VAP caused by CRAB in children could improve clinical outcomes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.1
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• pp.20-25
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• 2009

Thirty-eight Vibrio spp. were isolated from the sea waters harvested from the 22 stations located on the west coast of the Korean peninsula in September 2006. The isolates consisted of V. parahaemolyticus (n=21), V. alginolyticus (n= 16) and V. cholerae non-01 (n=1), among which 35 isolates displayed resistance against two of the tested antibiotics. Among the 38 isolates, 18 isolates exhibited multi-drug resistance against more than four 4 antibiotics. In particular, minimum inhibitory concentration $(MIC)_{50}$ and $MIC_{90}$ of ampicillin-resistant isolates were as high as $2,048{\mu}g{\cdot}mL^{-1}$ and $4,096{\mu}g{\cdot}mL^{-1}$ respectively. $\beta$-lactamase production was examined to analyze the ampicillin-resistance. Some Vibrio spp. isolates produced $\beta$-lactamase, however antibiotics resistance pattern and $\beta$-lactamase production were not clearly related to each other. A genetic relationship between resistance and gene expression was confirmed in the ampicillin-resistant isolates.

• Korean Journal of Veterinary Research
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• v.43 no.1
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• pp.113-120
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• 2003

The antimicrobial effect of ${\beta}$-lactam antibiotics, which had ${\beta}$-lactamase inhibitor activity, on Staphylococcus aureus isolated from mastitis was investigated in this study. Out of 166 isolates, 99 isolates (59.6%) produced ${\beta}$-lactamase, and 98 isolates of 99 were ${\beta}$-lactamase positive in above $12.5{\mu}g/m{\ell}$ MIC of penicillin. In the providence distribution, ${\beta}$-lactamase production rate of 4 providence, Gangwon, Gyeonggi, Chungcheong, and Jeolla was 100%, 65.7%, 58.8%, and 50.0%, respectively. Antibiotic activities of ${\beta}$-lactam antibiotics against lactamase positive isolates also were investigated. Antimicrobial effects of ampicillin/sulbactam or amoxicillin/clavulanic acid treated group were better than ampicillin or amoxicillin treated group. In antimicrobial effects on intracellular S aureus, there was no difference 1 hour and 4 hour treatment in control, ampicillin, and amoxicillin group, but in 18 hours treatment, ampicillin/sulbactam or amoxicillin/clavulanic acid had a better effect than ampicillin or amoxicillin (p<0.05).