• Bulletin of the Korean Chemical Society
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• 제30권3호
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• pp.687-690
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• 2009

A series of novel 1,3-diallyltrisulfane analogues were synthesized and assayed in vitro for antimicrobial activity against Gram positive, Gram negative bacteria and fungi. The antimicrobial activity of the 1,3-diallyltrisulfane derivatives showed, on the whole, very potent towards all the tested Gram positive, Gram negative and fungi (MIC ranging from 4 to 256 μg/mL). 1,3-Di(pent-4-enyl)trisulfane 3b and 1,3-bis(3-methylbut-2-enyl)trisulfane 3e exhibited the strongest antibacterial activity among all the compounds, and both of them were more active than 1,3-diallyltrisulfane (DATS). Results indicated the relationship of either carbon number or lipophilicity with antimicrobial activity presented “V” shape. These observations provided some predictions in order to further design 1,3-diallyltrisulfane derivatives with antimicrobial activity.

• 한국미생물·생명공학회지
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• 제50권1호
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• pp.147-156
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• 2022

Urinary tract infections (UTIs) are one of the most common infections in different age groups, including children. Bacteria are the main etiological agents of UTIs. The aim of the present study was to isolate, identify, and determine the antibiotic susceptibility of bacteria isolated from children with UTIs from Baghdad, Iraq. Three hundred and two urine samples were collected from children aged 6 months to 12 years. The samples were cultured on blood agar and MacConkey agar. The selected colonies were subjected to biochemical tests and antibiotic susceptibility analysis using the Vitek^® 2 Compact automated microbial identification system. In this sample, 299 bacteria were identified, of which, 267 were gram-negative bacteria, and 32 were gram-positive bacteria. Escherichia coli (56%) was the most commonly isolated gram-negative bacteria, followed by Pseudomonas aeruginosa (14%), Enterobacter spp. (10.48%), Klebsiella pneumoniae (9.36%), Proteus spp. (7.8%), Acinetobacter baumannii (1.5%), and Morganella morganii (0.37%). Enterococcus faecalis (62.5%) was the most commonly detected gram-positive bacteria, followed by Staphylococcus aureus (37.5%). E. coli and P. aeruginosa were the most antibiotic-resistant bacteria. Among the tested antibiotics, meropenem showed 100% sensitivity, followed by imipenem (97.4%), amikacin (91.8%), and tobramycin (83.5%). In contrast, the high frequencies of resistance were observed with cefixime (93.2%), cefotaxime (78.7%), and ceftriaxone/cefotaxime (71.2%). In conclusion, carbapenems and aminoglycosides are highly recommended for the empirical treatment of UTIs, while, Quinolones, penicillins, and cephalosporins are not suggested. Frequent antibiotics susceptibility testing are warranted to determine the resistance pattern of UTI bacteria.

• 약학회지
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• 제21권4호
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• pp.211-213
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• 1977

Since ampicillin, one of the important semi-synthetic derivatives of penicillins, is restricted in use because of its unfavorable physico-chemical and pharmacological properties, the author synthesized a new derivative, methampicillin lysinate and its physical and characteristics were determined. The antibacterial activity of this compound against ten species of Gram positive and negative bacteria in vitro showed that it was more active to Gram negative bactria than the positive and that was three times more potent than ampicillin trihydrate.

• Bulletin of the Korean Chemical Society
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• 제17권3호
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• pp.239-244
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• 1996

Mastoparan B (MP-B) that is a novel MP isolated from the hornet Vespa basalis, was studied as compared with MP, in terms of interaction with phospholipid bilayer and antimicrobial activity. MP-B has more hydrophilic amino acid residues in hydrophilic face of amphiphilic α-helical structure than MP. The both peptides exhibited considerably different effect on interaction with lipid bilayers, e.g. their conformation in the presence of acidic and neutral liposomes, dye-release ability from encapsulated liposomes, but on the whole the interaction mode was similar. On antimicrobial activity, MP had a strong activity against Gram-positive bacteria but no against Gram negative ones. Contrary to this, MP-B had a strong activity against Gram-positive and potent against Gram-negative ones. Since both peptides have almost same residues on the hydrophobic side, such more hydrophilic surface on the molecule seems to lead to the subtle change in its interaction with membranes, resulting in the alternation in its biological activity.

• Archives of Pharmacal Research
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• 제17권2호
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• pp.131-133
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• 1994

New istain-3-isonicotinylhydrazones, isationazine and its Mannich bases and spiro (indoline-3,2'-thiadiazoline)-2-one have been synthesized. These compounds have been screenced for their antibacterial activity against the Gram-positive and Gram-negative bacteria.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.307-308
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• 2005

Bioconverted hydroxy fatty acid from ${\gamma}-linolenic$ acid showed antibacterial activity against Gram-positive bacteria such as Bacillus subtilis (ATCC 6633), Listeria monocytogenes (ATCC 19166), Staphylococcus aureus (ATCC 6538) and S. aureus (KCTC 1916) and one Gram-negative bacteria, Pseudomonas aeruginosa (KCTC 2004) with MIC ranging from 250 to $750\;{\mu}g/ml$ against five of eleven bacteria tested.

• 한국식품영양과학회지
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• 제30권3호
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• pp.415-420
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• 2001

Eighteen kinds of medicinal edible herbs, which are nontoxic and has been widely used in traditional folk medicine, were extracted and antimicrobial activity of the extracts was investigated against various foodborne pathogens or food poisoning microorganisms. Among them, the ethanol extract of Quercus mongolica showed the strongest antimicrobial activities against Gram positive and Gram negative bacteria and followed by Quercus aliena and Quercus dentata, respectively. Thus, further study was conducted to determine the antimicrobial activity of Quercus species extracts. The plants were extracted with ethanol, methanol and water, respectively. The ethanol, methanol, and water extracts of Quercus mongolica leaf showed 10~21 mm inhibition zone against Gram positive and Gram negative bacteria at two thousand $\mu\textrm{g}$ per disc, but little antimicrobial activity was observed against fungi and yeast. The minimal inhibitory concentrations (MIC) of the ethanol extract of Quercus mongolica leaf was 250$\mu\textrm{g}$/mL against Bacillus cereus. Salmonella typhimurium, and Pseudomonas aeruginosa and 62.5~125 $\mu\textrm{g}$/mL against Staphylococcus aureus and Listeria monocytogenes, respectively.

• BMB Reports
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• 제29권6호
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• pp.545-548
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• 1996

CA(1-8)ME(1-12), the CA-ME hybrid peptide of the amino terminal segments of cecropin A (CA) and melittin (ME), has been reported to have a broad spectrum and improved potency without a hemolytic property. In order to obtain new synthetic peptides with powerful antibacterial activity without hemolytic activity, several hybrid peptides were designed from the sequences of CA, ME, magainin 2, bombinin and lactoferricin. All hybrid peptides were constructed to form an amphipathically basic-flexible-hydrophobic structure and synthesized by the solid phase method. Their hemolytic activities against human red blood cells and antibacterial activities against both Gram-positive and Gram-negative bacteria were detennined. CA(1-8)MA(1-12), CA(1-8)BO(1-12), MA(10-17)ME(1-12) and LF(20-29)ME(1-12) showed comparable activities with broad spectra against both Gram-positive and Gram-negative bacteria relative to CA(1-8)ME(1-12) but without hemolytic properties. These hybrid peptides, therefore, could be useful as model peptides to design a novel peptide with improved antibacterial activity and study on structure-activity relationships of antimicrobial peptides.

• BMB Reports
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• 제32권1호
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• pp.12-19
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• 1999

Gaegurin 4 (GGN4), a broad-spectrum antibiotic, is a 37-amino acid peptide isolated from the Korean frog, Rana rugosa. In this study, we have chemically synthesized and purified GGN4 analogues where the C-terminal portion is truncated and/or substituted with tryptophan. These peptides show significantly different biological activities depending on the location of tryptophan and the number of amino acids truncated from the C-terminal end. While deletion of 9 amino acids from the C-terminal seems to be marginally tolerable in maintaining the antimicrobial activity, further deletion of up to 14 amino acid residues decreases the potency by more than 60-fold towards Gram-positive, and 10-fold towards Gram-negative, bacteria. Surprisingly, the reduced activity of the shorter peptide can be completely restored by a single substitution of aspartic acid 16 to tryptophan 16 (D16W). Also, the truncation seems to decrease the specificity of antibiotic activity more towards Gram-positive than towards Gram-negative bacteria studied. These data suggest a partial role of the C-terminal region in determining the binding specificity and the activity of peptides upon binding to their target cell membranes.

• 미생물학회지
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• 제25권3호
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• pp.244-248
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• 1987

자연 발효과정중에 GRam 향성 및 음성세균의 수를 신속하고동시에 측정할 t ndlT는 방법을 검토하였다. 본 연구에서는 일반적으로 사용되고 있는 Gram 염색법을 응용하였다. 그 결과로써 Gram 염색법에의 세균수는 분광광도계에 의한 혼탁도와 A610=0.7의 범위내에서 비례관계가 성립하였다. 염색조작중 세척에 의한 균의 제거는 약 8%를 초과하지 않았다. 그리고 Escherichia coli와 Micrococcus luteus의 혼합액에서 이들의 분리 측정에 대한 표준오차는 $5.1\pm2.3$%이었다. 계수가능범위는 $5.5\times 10^{7}-1.0\times 10^{9}$세포 / ml 이었다. 그러므로 일반적인 Gram 염색법은 Gram 양성 및 음성 개체군이 혼합된 배양약에서 이들을 분별 측정하는데도 적용될 수 있다고 본다. 실제적으로, 대마침지와 김치 발효과정에서 균 생장의 동역학적 관계를 검토하였다.