• 한국축산식품학회지
• /
• 제38권2호
• /
• pp.391-402
• /
• 2018

The aim of the present work was to provide information about Enterococcus strains isolated from pre-packaged chicken samples in Ankara (Turkey), focusing on their prevalence, phenotypic and genotypic characteristics, and antibiotic resistance. We report the first study on the occurrence of antibiotic resistant enterococci in pre-packaged chicken samples in Ankara. A total of 97 suspicious enterococcal isolates were identified from 122 chicken samples. All isolates were identified to species level by phenotypic and molecular methods. In the 16S rDNA sequence analysis, Enterococcus faecium (61.85%) and Enterococcus faecalis (38.15%) were found to be the most frequently detected Enterococcus spp. Of the 97 isolates tested for hemolytic activity, 12.37% enterococcal strains were ${\beta}$-hemolytic. ${\beta}$-Hemolysin was most prevalent among E. faecium (58.33%) compared to E. faecalis (41.66%). Disk diffusion method was used for determining of antibiotic resistance. The analysis of the antimicrobial resistance of the 97 Enterococcus isolates revealed that the resistance to kanamycin (98.96%), rifampicin (80.41%) and ampicillin (60.82%) was most frequent. Furthermore, resistance to erythromycin (38.14%) and ciprofloxacin (34.02%) was also observed. The frequencies of resistance to tetracycline (9.27%), penicillin G (8.24%), and chloramphenicol (3.09%), gentamicin (2.06%) and streptomycin (1.03%) were low. None of the isolates was resistant to vancomycin. Multi-drug resistance was found in 97.93% of Enterococcus strains. E. faecium strains showed a more resistant phenotype than E. faecalis strains according to the antibiotic resistance levels. The results of this study indicated that chicken meat is a potential reservoir for the transmission of antibiotic resistance from animals to humans.

• Journal of Microbiology and Biotechnology
• /
• 제26권3호
• /
• pp.521-529
• /
• 2016

Extensive use of antibiotics over recent decades has led to bacterial resistance against antibiotics, including gentamicin, one of the most effective aminoglycosides. The emergence of resistance is problematic for hospitals, since gentamicin is an important broad-spectrum antibiotic for the control of bacterial pathogens in the clinic. Previous study to identify gentamicin resistance genes from environmental samples have been conducted using culture-dependent screening methods. To overcome these limitations, we employed a metagenome-based culture-independent protocol to identify gentamicin resistance genes. Through functional screening of metagenome libraries derived from soil samples, a fosmid clone was selected as it conferred strong gentamicin resistance. To identify a specific functioning gene conferring gentamicin resistance from a selected fosmid clone (35-40 kb), a shot-gun library was constructed and four shot-gun clones (2-3 kb) were selected. Further characterization of these clones revealed that they contained sequences similar to that of the RNA ligase, T4 rnlA that is known as a toxin gene. The overexpression of the rnlA-like gene in Escherichia coli increased gentamicin resistance, indicating that this toxin gene modulates this trait. The results of our metagenome library analysis suggest that the rnlA-like gene may represent a new class of gentamicin resistance genes in pathogenic bacteria. In addition, we demonstrate that the soil metagenome can provide an important resource for the identification of antibiotic resistance genes, which are valuable molecular targets in efforts to overcome antibiotic resistance.

• Pediatric Infection and Vaccine
• /
• 제22권3호
• /
• pp.178-185
• /
• 2015

목적: 국내 소아 그람음성균혈증에서 항생제 내성변화 및 항생제 사용량과의 관계를 분석하였다. 방법: 최근 10년간 18세 이하 입원 환자의 혈액에서 분리된 그람음성균의 항생제 내성률 변화 및 항생제 사용량과의 관계를 분석하였다. 결과: 폐렴막대균, 대장균, 녹농균, 아시네토박터 바우마니의 분리율은 연간 혈액배양 1,000건당 각각 4.6례, 3.5례, 3.4례 및 2.2례였다. 폐렴막대균에서 광범위 세팔로스포린에 대한 내성변화는 없었으나 2010년부터 카바페넴 내성 폐렴막대균이 동정된 후 점차 빈도가 증가하였다. 대장균의 광범위 세팔로스포린 내성이 10%에서 50%로 아시네토박터 바우마니의 카바페넴 내성이 11%에서 71%로 크게 증가하였다(P for trend <0.01). 녹농균은 여러 항생제에 높은 내성을 보였으나 유의한 내성변화를 보이지 않았다. 대장균의 cefepime 내성과 cefepime 사용량 사이에 유의한 양의 상관관계를 보였다(r=0.900, P=0.037). 결론: 국내 소아에서 발생한 그람음성균 균혈증 분석시 카바페넴 및 광범위 세팔로스포린 내성이 증가하였고 일부에서 항생제 사용량과의 관련성을 확인하였다. 이는 원내 경험적 항생제 결정시 중요한 고려 사항이며 추후에도 지속적인 원내 항생제 사용량 및 내성률에 대한 감시가 필요하겠다.

• 한국환경과학회지
• /
• 제21권3호
• /
• pp.267-276
• /
• 2012

Spaceflights results in the reduction of immune status of human beings and increase in the virulence of microorganisms, especially gram negative bacteria. The growth of Klebsiella pneumoniae is enhanced by catecholamines and during spaceflight, elevation in the levels of cortisols occurs. So it is necessary to know the changes in physiology, virulence, antibiotic resistance and gene expression of K. pneumoniae under microgravity conditions. The present study was undertaken to study effect of simulated microgravity on growth, morphology, antibiotic resistance and cross stress resistance of K. pneumoniae to various stresses. The susceptibility of simulated microgravity grown K. pneumoniae to ampicillin, penicillin, streptomycin, kanamycin, hygromycin and rifampicin were evaluated. The growth of bacteria was found to be fast compared with normal gravity grown bacteria and no significant changes in the antibiotic resistance were found. The bacteria cultured under microgravity conferred cross stress resistance to acid, temperature and osmotic stress higher than the normal gravity cultured bacteria but the vice versa was found in case of oxidative stress.

• 대한수의학회지
• /
• 제55권1호
• /
• pp.41-46
• /
• 2015

Increasing presence of wild boar around cities and suburban areas is a growing concern with respect to agronomy, environmental ecology, and public safety. In this study, antibiotic resistance profiles of Escherichia (E.) coli isolated from wild boar and domestic pig fecal samples were compared. Eighty E. coli samples were isolated from wild boars. Resistance of the bacteria to 14 common antimicrobial agents used in human and veterinary medicine was evaluated. Ninety-five E. coli isolates from domestic pig farms were used for comparison. Common and distinct antibiotic resistance patterns were observed when comparing wild boar and domestic pig isolates, indicating that wild boars may significantly influence environmental microbiology.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
• /
• pp.541-544
• /
• 2004

The purpose of this study is to examine the antibiotic and physical properties of antibiotic concrete added inorganic liquor-type antibiotic agent(as named for Antibio-C) as the basic data for the development of antibiotic concrete. The main experimental variables were the types of antibiotic agents and it is tested for the properties of antibiotic, flow, compressive strength, crack-resistance and durability of concrete. As results, concrete containing antibiotic agent presented the strong antibiotic activities compared with non-added concrete. Also antibiotic concrete showed the higher or equality properties than non-added concrete with respect to compressive strength, crack resistance and durability such as neutralization depth.

• 대한수의학회지
• /
• 제45권1호
• /
• pp.75-83
• /
• 2005

The purpose of this study was to investigate the antibiotic resistance pattern of E. coli and Salmonella spp. isolated from chicken feces. One hundred and forty-seven E. coli isolates showed resistance to tetracycline (95.2%), erythromycin (89.2%), ampicillin (70.1%), streptomycin (59.2%), cephalothin (56.5%), sulfamethoxazole/trimethoprim (53.7%), ciprofloxacin (57.1%), enrofloxacin (59.2%) and norfloxacin (57.1%). The multiple resistance was seen in 144 isolates (97.9%) and the rate of five, six and seven drugs resistance pattern were 20.4%, 18.4% and 16.3%, respectively. Also, the multiple resistance of E. coli to twelve drugs were seen in 1 isolates (0.7%). Fourteen Salmonella spp. showed resistance to ampicillin (50.0%), streptomycin (57.1%), erythromycin (64.3%) and tetracycline (57.1%) and the rate of two and three drugs resistance pattern were 4 isolates (28.6%), respectively. The prevalence of resistant organisms in Korea probably reflects lack of proper antibiotic policy resulting in prolonged and indiscriminate use of antimicrobial agents.

• 한국미생물·생명공학회지
• /
• 제51권3호
• /
• pp.268-279
• /
• 2023

The pharmaceutical industry in Bangladesh produces a diverse range of antibiotics for human and animal use, however, waste disposal management is inadequate. This results in substantial quantities of antibiotics being discharged into water bodies, which provide suitable environment for the growth of antibiotic-resistant bacteria, capable of spreading resistance genes. This study intended for exploring the bacterial antibiotic resistance profile in adjoining aquatic environmental sources of pharmaceutical manufacturing facilities in Bangladesh. Seven surface water samples were collected from the vicinity of two pharmaceutical industries located in the Savar area and 51 Escherichia coli isolates were identified using both phenotypic and genotypic methods. Antibiotic susceptibility tests revealed the highest percentage of resistance against ampicillin, azithromycin, and nalidixic acid (100%) and the lowest resistance against meropenem (1.96%) out of sixteen different antibiotics tested. 100% of the study E. coli isolates were observed with Multidrug resistance phenotypes, with the Multiple Antibiotic Resistance (MAR) value ranging from 0.6-1.0. Furthermore, 69% of the isolates were Extended Spectrum Beta-Lactamases (ESBL) positive as per the Double Disk Diffusion Synergy Test (DDST). ESBL resistance genes bla_TEM, bla_CTX-M-13, bla_CTX-M-15, and bla_SHV were detected in 70.6% (n = 36), 60.8% (n = 32), 54.9% (n = 28), and 1.96% (n = 1) of the isolates, respectively, by Polymerase Chain Reaction (PCR). Additionally, 15.68% (n = 8) of the isolates were positive for E. coli specific virulence genes in PCR. These findings suggest that pharmaceutical wastewater, if not properly treated, could be a formidable source of antibiotic resistance spread in the surrounding aquatic environment. Therefore, continued surveillance for drug resistance among bacterial populations around drug manufacturing facilities in Bangladesh is necessary, along with proper waste disposal management.

• Fisheries and Aquatic Sciences
• /
• 제21권2호
• /
• pp.3.1-3.10
• /
• 2018

Background: Vibrio parahaemolyticus is one of the most common causes of seafood-borne illnesses in Korea, either directly or indirectly, by consuming infected seafood. Many studies have demonstrated the antibiotic susceptibility profile of V. parahaemolyticus. This strain has developed multiple antibiotic resistance, which has raised serious public health and economic concerns. This article reviews the food-borne outbreaks, distributions, virulence, and antibiotic resistance profiles of V. parahaemolyticus in Korea during 2003-2016. Main body: V. parahaemolyticus infections appeared to be seasonally dependent, because 69.7% of patient infections occurred in both August and September during 2003-2016. In addition, the occurrence of V. parahaemolyticus in marine environments varies seasonally but is particularly high in July, August, and September. V. parahaemolyticus isolated from aquaculture sources on the Korean coast varied in association with virulence genes, some did not possess either the tdh (thermostable direct hemolysin) or trh (tdh-related hemolysin) genes, and a few were positive for only the trh gene or both genes. The high percentage of ampicillin resistance against V. parahaemolyticus in the aquatic environment suggests that ampicillin cannot be used to effectively treat infections caused by this organism. Short conclusion: This study shows that the observed high percentage of multiple antibiotic resistance to V. parahaemolyticus is due to conventionally used antibiotics. Therefore, monitoring the antimicrobial resistance patterns at a national level and other solutions are needed to control aquaculture infections, ensure seafood safety, and avoid threats to public health caused by massive misuse of antibiotics.

• 한국환경농학회지
• /
• 제20권5호
• /
• pp.330-334
• /
• 2001

The polymorphism of Azospirillum isolates from ornamental rhizosphere and two reference strains were examined with respect to intrinsic antibiotic resistance (IAR) profile. All the isolates showed different intrinsic resistances to different antibiotics viz., tetracycline, kanamycin, nalidixic acid, streptomycin, ampicillin, spectinomycin and chloramphenicol. All the strains demonstrated susceptibility to high concentration of all antibiotics used in the present experiment. In addition to these general patterns, we also obseved the multiple antibiotic resistances of Azospirillum strains. The Azospirillum sp. OAD-11 was resistant to tetracycline, streptomycin and ampicillin, and Azospirillum sp. OAD-57 was resistant to tetracycline and streptomycin. Conversely, Azospirillum sp. OAD-9 possessed the dual susceptibility to tetracycline and spectinomycin, whereas Azospirillum sp. OAD-37 was dual susceptible to streptomycin and kanamycin. Such multiple antibiotic resistant/susceptible traits could be useful for the identification of the strains in field experiments or in molecular genetic transfer experiments.