Rapid Labeling of Gram-Negative Bacteria Using Colistin as a Ubiquitous Targeting Ligand

류제성,정현정 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

Gram-negative bacteria is a serious cause of infections, which have to be rapidly and accurately diagnosed for specific and early treatment. Because conventional molecular tests based on antibodies or oligonucleotide probes, have limitations in their non-specific binding, cross-reactivity, and difficult access due to large molecular size, rapid labeling on bacterial cell wall is difficult to achieve. In order to differentiate Gram-negative bacteria from Gram-positive bacteria, we investigate on colistin (polymyxin E) due to its molecular attaching properties on lipopolysaccharide, known as the cell wall components of Gram-negative bacteria. Herein, we synthesized colisitn-Cy3 to labeling and detecting Gram-negative bacteria rapidly and accurately. In 1 hour labeling and washing process, we successfully confirmed colistin-Cy3 and Gram-negative bacteria interaction, and quantified that this bacteria makes stronger fluorescent labeling than others with fluorescent reader, microscope.

1P-218 Rapid detection of Gram-negative bacteria using Colistin as a ubiquitous targeting ligand

류제성,정현정 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1

Gram-negative bacteria is a serious cause of infections, which have to be rapidly diagnosed for specific and early treatment. Conventional methods include microbial culture, immunoassays, and nucleic acid testing, however have limitations in involving time-consuming procedures, lack of specific ligands, or expensive equipments. Colistin bind specifically to the lipopolysaccharide on the cell wall of Gram-negative bacteria. Herein, we apply Colistin as the ligand to ubiquitously target Gram-negative bacteria for rapid detection with high selectivity. We prepared colistin modified with Cy3, to rapidly label and visualize Gram-negative bacteria. Labeling of the bacteria with colistin-Cy3 was done by incubation for 10 min, and we successfully observe bright fluorescence on Gram-negative bacteria by microscopy, as well as strong signals by quantification. This labeling method can be used as a rapid and simple molecular detection platform for ubiquitous detection of Gram-negative pathogens.

Prevalence and antimicrobial susceptibility of gram-negative bacteria isolated from bovine mastitis between 2003 and 2008 in Korea

Nam, H.M.,Lim, S.K.,Kang, H.M.,Kim, J.M.,Moon, J.S.,Jang, K.C.,Kim, J.M.,Joo, Y.S.,Jung, S.C. American Dairy Science Association 2009 Journal of dairy science Vol.92 No.5

The objective of this study was to assess trends in the prevalence and distribution of gram-negative bacteria isolated from bovine mastitis and their antimicrobial susceptibilities during a 6-yr period between 2003 and 2008 in Korea. Escherichia coli, Pseudomonas fluorescens, Klebsiella pneumoniae, Enterobacter cloacae, Acinetobacter lwoffi/junii, Pseudomonas aeruginosa, and Serratia marcescens were the most commonly observed pathogens during this period. Generally, gram-negative bacteria showed low susceptibilities to most of the antimicrobials tested in this study, except amikacin and gentamicin. Although these 2 aminoglycosides were broadly active against gram-negative bacteria, less than half of those bacteria showed susceptibilities to streptomycin. The β-lactams, except piperacillin, had the lowest activity among antimicrobials tested in this study. Susceptibilities to chloramphenicol and trimethoprim were fairy high in all genera of gram-negative bacteria, except Acinetobacter spp. and Pseudomonas spp., whereas relatively high resistance to tetracycline was observed uniformly among gram-negative bacteria. There was no significant change in the prevalence of bacterial and the proportion of antimicrobial resistance among gram-negative bacteria isolates during a 6-yr period.

Ubiquitous Detection of Gram-negative Bacteria Using Colistin as the Targeting Ligand

류제성,임산해,정현정 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

The rapid and differential detection of Gram-negative infections would greatly reduce the overuse of antibiotics, and minimize the spread of antibiotic resistance. However, conventional diagnostics relies on microbial culture which is time-consuming, while molecular methods involve complex processing procedures. Herein, we studied the use of antibiotics as a targeting ligand for ubiquitous detection of Gram-negative bacteria. We chose colistin as the targeting ligand, which includes cationic residues (L-α-γ-diaminobutyric acid) that specifically interact with lipopolysaccharide (LPS) on Gram-negative bacteria. We prepared Cy3-conjugated colistin which were added to different types of pathogenic bacteria for incubation. Selective labeling of Gram-negative bacteria was demonstrated by confocal microscopy and spectrofluorometry. Our study presents a rapid and simple labeling procedure, which can be applied in the clinic for diagnosing Gram-negative infections.

Multidrug-Resistant Gram-Negative Bacterial Infections in a Tertiary-Care Hospital in Northern Ghana: A Three-Year Retrospective Analysis

Kennedy Mensah Osei,최희강,David Eklu Zeyeh,Salifu Alikamatu,Esther Owusu Boateng,Vandarith Nov,Le Phuong Nguyen,Khadija Kubura,Bernard Bobzah,용동은 대한임상미생물학회 2022 Annals of clinical microbiology Vol.25 No.1

Background: A variety of clinically important pathogens have developed multidrug resistance(MDR), which threatens global public health. This study aimed to determine the incidence,patterns, and trends of MDR of gram-negative bacterial isolates in clinical specimens in theTamale Teaching Hospital, Ghana. Methods: This retrospective study analyzed gram-negative bacterial isolates andantimicrobial susceptibility test (AST) results of patients who visited the Tamale TeachingHospital laboratory between 2017 and 2019. Results: A total of 2,779 gram-negative bacterial isolates and their phenotypic AST resultswere analyzed. From these, 1,297 gram-negative bacteria (46.7%) were isolated from urinesamples, while the rest were isolated from sputum (20.9%), wound (14.3%), and swabs(11.7%) samples, etc. Escherichia coli (23.8%) was the most common gram-negative pathogenfound predominantly in the urine samples (33.2%). All gram-negative bacteria isolatedbetween 2017 and 2019 showed high MDR. Klebsiella pneumoniae gradually increased itsMDR from 84.0% in 2017, 89.5% in 2018, to 95.1% in 2019. On the other hand, the MDR ratesin Pseudomonas aeruginosa were approximately 65.8%, varying from 59.5% in 2017 to78.7% in 2019. Among tested antimicrobials, amikacin was the most effective. Resistance toamikacin in Enterobacter spp., E. coli, and K. pneumoniae in vitro were 16.2%, 11.8%, and17.7%, respectively. Conclusion: The study has shown that the high levels of MDR in gram-negative bacteriaisolated may be associated with the infections recorded at the Tamale Teaching Hospital. The major gram-negative pathogens isolated have resistance to penicillins, cephalosporins,and fluoroquinolones. Aminoglycosides can offer high antibiotic activity to overcome gramnegativebacterial resistance. Further studies will be needed to decide policy direction oninfection prevention and control, and antimicrobial stewardship programs

Bacteremia in Pediatric Cancer Patients : Causative Organisms and Antibiotic Sensitivities

김용한,이현동,하정옥,Kim, Yong-Han,Lee, Hyun-Dong,Hah, Jeong-Ok The Korean Pediatric Society 2005 Clinical and Experimental Pediatrics (CEP) Vol.48 No.6

목 적 : 면역 저하된 소아 암 환자에서 균혈증은 조기에 적절한 치료를 하지 못하면 이환율과 사망률이 높아 질 수 있는 질환으로서 호발 원인균의 발생 빈도 및 항생제에 대한 감수성은 지역적 시기적으로 변화하는 경향이 있으므로 이를 조사하여 경험적 항생제 선택에 도움을 주고자 하였다. 방 법 : 1995년 9월부터 2003년 8월까지 영남대학교 의과대학부속병원 소아과에 입원한 소아 암 환자를 대상으로 병력지와 혈액배양검사 결과를 조사하여 균혈증이 확진된 39명, 58례를 대상으로 원인 균의 종류 및 항생제 감수성을 조사 분석하였다. 결 과 : 소아 암 환자에서 균혈증의 발생빈도는 균혈증이 의심되어 혈액배양을 시행한 1,022례 중 58례로 5.7%였다. 균혈증을 일으킨 가장 흔한 원인 균은 그람양성균으로 총 37례(63.8%) 였고 그람음성균은 총 21례(36.2%)였다. 그람양성균의 경우 Staphylococcus epidermidis (22례, 37.9%), Staphylococcus aureus (10례, 17.3%), Streptococcus (5례, 8.6%) 순이었고, 그람음성균의 경우 Escherichia coli (7례, 12%), Enterobacter (4례, 6.9%), Klebsiella (4례, 6.9%), Serratia (2례, 3.5%), Acinetobacter (2례, 3.5%), Proteus (1례, 1.7%), Morganella morganii (1례, 1.7%) 순으로 나타났다. 항생제 감수성 검사에서는 그람양성균 37례 중 6례(16%)에서만 penicillin 감수성을 나타내었고, 15례(40%)에서 oxacillin 감수성을 나타내었다. Staphylococcus aureus는 1례를 제외한 모든 예에서 vancomycin에, Staphylococcus epidermidis는 1례를 제외한 모든 예에서 teicoplanin에 감수성을 나타내었다. 그람음성균의 경우, 21례 중 2례(10%)만이 cefotaxime에, 4례(19%)에서만 ceftazidime에 감수성을 나타내었다. Aminoglycoside에는 21례 중 6례(29%) 에서만 감수성을 나타내었으며, 21례 모두에서 imipenem에 감수성을, 2000년 이후부터 감수성 검사를 시행한 meropenem에도 모든 예에서 감수성을 나타내었다. 결 론: 균혈증이 의심되는 소아 암 환자에서 그람양성균에 의한 균혈증이 증가하는 점과 그람양성균과 그람음성균 모두 항생제 다제내성 빈도가 증가하고 있음을 유념하여 적절한 항생제를 선택해야 할 것이다. Purpose : Bacteremia in immunocompromised pediatric cancer patients can lead to high morbidity and mortality, if not treated early and properly. The incidence and antibiotic sensitivities to common pathogens of bacteremia in pediatric cancer patients are liable to change, according to region and time. We investigated the causative organisms and antibiotic sensitivities of bacteremia in pediatric cancer patients to assess the adequacy of empiric antimicrobial therapy. Methods : From September 1995 to August 2003, we retrospectively evaluated 58 episodes in 39 pediatric cancer patients with bacteremia treated at the Pediatric Department of Yeungnam University Hospital. We investigated and analyzed the causative organisms and the antibiotic sensitivity test results by reviewing the records of the microbiologically proven positive blood culture results. Results : The incidence of bacteremia in pediatric cancer patients in this study was 5.7 percent (58 episodes out of 1,022 occasions of blood cultures). Gram-positive organisms were isolated more often than gram-negative organisms (63.8 percent vs 36.2 percent) in the following order : Staphylococcus epidermidis (37.9 percent), Staphylococcus aureus (17.3 percent), Escherichia coli (12 percent), Streptococcus (8.6 percent), Enterobacter (6.9 percent), Klesiella (6.9 percent), Serratia (3.5 percent), Acinetobacter (3.5 percent), Proteus (1.7 percent) and Morganella morganii (1.7 percent). In antibiotic sensitivity tests, only six of 37 isolates (16 percent) of gram positive bacteria were sensitive to penicillin and 15 of 37 isolates (40 percent) were sensitive to oxacillin. All except one Staphylococcus aureus were sensitive to vancomycin and all except one Staphylococcus epidermidis were sensitive to teicoplanin among 37 isolates of gram positive bacteria. In the case of gram negative bacteria, two of 21 isolates (10 percent) and four of 21 isolates (19 percent) were sensitive to cefotaxime and ceftazidime, respectively. Only six of 21 isolates (29 percent) were sensitive to aminoglycoside, but all 21 isolates (100 percent) were sensitive to imipenem. All seven isolates tested after the year 2000 were sensitive to meropenem. Conclusion : In conclusion, we should choose the proper antimicrobials in treating pediatric cancer patients with suspected bacteremia, reflecting the increasing episodes of gram positive bacteremia and polymicrobial resistance of gram positive and negative organisms.

The Cell and Genetic Characteristics of Slime Forming Bacteria on Antibiotic Resistance in the Paper-making Process

Eun-HeeKim,오정수,강규영,조병묵 한국목재공학회 2002 목재공학 Vol.30 No.3

The seven strains, Pseudomonas paucimobilis, Pseudomonas cepacia, Staphylococcus auricularis, Staphylococcus saprophyticus, Acidovorax spp., Acinetobacter calcoaceticus, and Actinobacillus capsulatus were tested with three slimicides. Most of the tested bacteria were inhibited with slimicide K (an isothiazolin based compound), even at its low concentration, except for Actinobacillus capsulatus and Staphylococcus auricularis. Both slimicides B (an organic bromine based compound) and S (aldehydes) also couldn't prevent these two strains even at their highest concentration. Five different sizes of plasmid DNA were isolated from Actinobacillus capsulatus. Staphylococcus auricularis, a gram-positive bacteria, showed the slimy substances around its cell distinctively. The results suggest that two strains, Actinobacillus capsulatus, Staphylococcus auricularis, have presumably developed a resistance to the slimicide, by plasmid DNA or slimy substance.Our findings also suggest that not only gram-negative bacteria, but also gram-positive bacteria should not be neglected.

Strategies to combat Gram-negative bacterial resistance to conventional antibacterial drugs: a review

Priyanka Bhowmik,Barkha Modi,Parijat Roy,Antarika Chowdhury 질병관리본부 2023 Osong Public Health and Research Persptectives Vol.14 No.5

The emergence of antimicrobial resistance raises the fear of untreatable diseases. Antimicrobial resistance is a multifaceted and dynamic phenomenon that is the cumulative result of different factors. While Gram-positive pathogens, such as methicillin-resistant Staphylococcus aureus and Clostridium difficile, were previously the most concerning issues in the field of public health, Gram-negative pathogens are now of prime importance. The World Health Organization’s priority list of pathogens mostly includes multidrug-resistant Gram-negative organisms particularly carbapenem-resistant Enterobacterales, carbapenem-resistant Pseudomonas aeruginosa, and extensively drug-resistant Acinetobacter baumannii. The spread of Gram-negative bacterial resistance is a global issue, involving a variety of mechanisms. Several strategies have been proposed to control resistant Gram-negative bacteria, such as the development of antimicrobial auxiliary agents and research into chemical compounds with new modes of action. Another emerging trend is the development of naturally derived antibacterial compounds that aim for targets novel areas, including engineered bacteriophages, probiotics, metal-based antibacterial agents, odilorhabdins, quorum sensing inhibitors, and microbiome-modifying agents. This review focuses on the current status of alternative treatment regimens against multidrug-resistant Gram-negative bacteria, aiming to provide a snapshot of the situation and some information on the broader context.

샘플착용 미용 콘택트렌즈의 세균 오염에 대한 관리방법

고훈,이흠숙,박미정,김은혜 한국안광학회 2008 한국안광학회지 Vol.13 No.1

목적: 본 연구에서는 샘플착용 미용 콘택트렌즈의 적절한 관리방법을 알아보고자 하였다. 방법: 10대 20대 미용 콘택트렌즈 착용자 50명을 대상으로 한 설문조사를 통해 미용 콘택트렌즈 구입 시 샘플착용 실태를 파악하였다. 또 한 샘플착용 미용 콘택트렌즈를 2주, 4주, 6주 동안 착용시 발생하는 그람음성균 및 진균의 오염 정도를 측정하고 적절한 관리방법에 의해 이러한 오염이 방지될 수 있는 지를 알아보았다. 결과: 설문 조사결과, 평균 4.5개의 샘플 착용 미용 콘택트렌즈를 시험착용 후 구매하는 것으로 나타났다. 그람음성균 및 진균의 오염은 샘플착용렌즈의 착 용기간에 따라 통계적으로 유의하게 증가하였다. 착용시마다 문지르기와 보존액을 교체하는 Group 1과 문지르기를 하지 않은 채 보존액 교체만을 해준 Group 2에서는 그람음성균 및 진균의 증식이 완벽하게 방지되었다. 1주 간격 으로 관리를 한 Group에서는 그람음성균 및 진균의 증식이 어느 정도 억제되었으며, 문지르기가 균의 오염 방지에 도움이 되었다. 2주 간격의 관리는 균의 오염 방지에 거의 효과가 없었다. 결론: 착용할 때마다 보존액을 교체해주 는 것만으로도 샘플착용 미용 콘택트렌즈에서의 그람음성균 및 진균의 오염을 완벽하게 방지할 수 있었다. Purpose: To investigate the proper care system of sample-wearing cosmetic contact lens (SWCCL). Methods: Research on the actual condition about SWCCL was examined in fifty cosmetic contact lens wearer in their 10s and 20s by the questionnaire. Also, the extents of the contamination of gram-negative bacteria and fungi were measured in SWCCL after wearing for 2, 4 and 6 weeks, and it was investigated whether the proper care system could prevented the contamination. Results: As the result of the questionnaire, people purchased the cosmetic contact lens after trying SWCCL with a mean of 4.5. The contamination of gram-negative bacteria and fungi were significantly increased in SWCCL-wearing period-dependent manner. In both Group 1 (rubbing SWCCL and exchanging preserving solution every wearing of SWCCL) and Group 2 (only exchanging preserving solution every wearing of SWCCL without rubbing SWCCL), the contamination of gram-negative bacteria and fungi were prevented perfectly. In the case of Groups having every-week care, the proliferation of gram-negative bacteria and fungi were somewhat suppressed, and rubbing was helpful of decreasing the contamination. The biweekly care had scarcely any effect for preventing the contamination. Conclusions: By exchanging the preserving solution every wearing of SWCCL, the contamination of gram-negative bacteria and fungi could be suppressed perfectly.

Gram-Negative Bacteria’s Outer Membrane Vesicles

Kim Jeong Yeon,Suh Jin Woong,Kang Jae Seong,Kim Sun Bean,Yoon Young Kyung,Sohn Jang Wook 대한감염학회 2023 Infection and Chemotherapy Vol.55 No.1

Outer membrane vesicles (OMVs) are spherical bilayered nanoparticles derived from the outer layer of Gram-negative bacteria. Bacteria communicate with nearby bacteria, their environment, and the cells of their host by secreting OMVs, which are essential for their survival. OMVs also play a critical role in bacterial pathogenesis since they are loaded with virulence factors, toxins, and enzymes. OMVs may modulate the immune response of the host by initiating inflammation through cytokine production and activating the innate immune response. OMVs also contribute to the resistance of bacteria to antibiotics by carrying antibiotic-degrading enzymes and acting as natural protection barriers. Concerns have also been raised regarding OMVs mediating the transfer of antibiotic resistance. Due to their advantageous properties, OMVs are attractive platforms for vaccine discovery and drug delivery research. In this review, we discuss the fundamental structure and biogenesis mechanisms of OMVs as well as their multifaceted roles in bacterial infection pathogenesis and host immune responses. We also discuss application examples of OMVs.