In order to evaluate contamination of the topical eye drugs, 112(36 kinds) medications used over 1 month by the patients and 80(25 kinds) medications used at OPD(outpatient department) were studied by culturing the caps, the tips and the contents. Coagulase-negative staphylococcus was mainly isolated from the caps and the tips(p<0.05). But the other gram-positive bacteria, gram-negative bacteria and fungi were isolated from all medication sites. The most frequent site of contamination was the tips of the medications. Frequency of contamination based on detail of medications and preservatives of medications was not statistically significant(p>0.05). The medications used by the patients for a long time in comparison with the medications used at OPD were significantly more likely to be contaminated(p<0.0001). Therefore, we think that the topical eye durgs should be used with proper instillation and storage for a short period because of increase risk of contamination.
Fungi ; Gram-Negative Bacteria ; Gram-Positive Bacteria ; Humans ; Staphylococcus

Quorum sensing (QS) plays a major role in the outbreak mechanism of foodborne diseases caused by food poisoning and food spoilage. QS affects the formation of cell membrane and pathogenicity ofpathogenic bacteria. Through the in-depth understanding of QS molecules of food-borne pathogens, we describe here the types of signal molecules produced by Gram-negative and Gram-positive bacteria, and the differences in QS molecules. Meanwhile, we introduce the detection of QS molecules by different technologies. According to the influence of QS on food, we propose also future research needs for the control of foodborne pathogenic bacteria.
Gram-Negative Bacteria ; Gram-Positive Bacteria ; Quorum Sensing

A clinical observation was done on random 42 cases of acute and uncomplicated bacterial pyelonephritis. The following results were obtained: 1. All cases were female. 2. The most common age group was 2nd decade (47.6%). 3. All isolated organisms were Gram negative bacteria and E. coli was most common (90%). 4. On excretory urogram, 3 cases (7%)were abnormal and one of them showed acute segmental pyelonephritis. 5. The right side was affected 3 times more than left and 8 cases were bilateral.
Female ; Gram-Negative Bacteria ; Humans ; Pyelonephritis*

No abstract available.
Animals ; Gram-Negative Bacteria* ; Interleukin-2* ; Mice*

Aims: This study aimed to isolate and identify lactobacilli strains that have antagonistic activity against multidrug resistant (MDR) isolates of Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa and evaluate their probiotic properties. Methodology and results: Twenty-one Lactobacillus isolates were collected, and their antimicrobial activity was assessed by agar well diffusion, broth microdilution and time-kill test. The probiotic potential of the isolates was evaluated as well. The bacterial culture and cell free supernatant (CFS) of all isolates exhibited antibacterial activity against all MDR isolates. Out of 21 isolates, 4 isolates (A31, B35, S20 and S25) displayed the highest antimicrobial activity and further evaluated. The minimum inhibitory percentages of CFS from selected isolates against pathogens ranged from 10 to 30% and the bactericidal percentages ranged from 20 to 50%. The inhibitory activity of CFS was not changed after heating but abrogated as the pH neutralized. The growth kinetic of the MDR pathogens was significantly reduced in the presence of the CFS of all isolates. The isolates had a less than 1-log reduction in their viability in acid tolerance test and could grow in the presence of 0.3% bile salts. Strains S20, S25 and B35 exhibited high coaggregation with E. coli (51.7-73.3%), P. aeruginosa (53.7-69.3%) and K. pneumoniae (49.7-65.3%). Molecular identification revealed that the isolates were Lactobacillus rhamnosus (B35) and Lactobacillus paracasei (S20, S25, A31). Conclusion, significance and impact of study The results suggest that these lactobacilli isolates may have potential applications for controlling and preventing colonization of infections caused by MDR pathogens.
Lactobacillales ; Kefir ; Probiotics ; Gram-Negative Bacteria

Aims: Attention to ice nucleation proteins has increased for more than two decades. Ice nucleation proteins have been utilized for artificial snow-making known as Snowmax™, cryopreservation of tissues and cells, and cloud condensation nuclei. There is a direct relationship between bacterial growth and ice nucleation activity. Therefore, the optimization of the culture medium seems necessary. Methodology and results: The effect of different carbon and nitrogen sources on the growth of a new native Pseudomonas sp. IRL.INP1 was evaluated by using fractional factorial design, the path of the steepest ascent experiment and central composite design. Ice nucleation activity, biomass and whole-cell protein were identified afterward. The model predicted by response surface methodology indicated that the maximum bacterial growth was observed when sucrose, ammonium sulfate [(NH4)2SO4] and manganese (II) (Mn2+) were utilized at 12.46 g/L, 321.97 mg/L and 938.09 µM, respectively. Also, 1.10 g/L biomass and 0.85 µg/µL whole-cell proteins were gained, and the isolate showed ice nucleation activity 31 sec sooner after optimization. Conclusion, significance and impact of study Ice nucleation proteins are growth-dependent and the growth condition optimization leads to higher bacterial cells growth. Therefore, best bacterial growth was obtained when proper carbon and nitrogen sources were used, and ice nucleation activity was observed in shorter time. This is the first study concerning ice nucleation activity optimization using different carbon and nitrogen sources.
Gram-Negative Bacteria--growth & ; development ; Pseudomonas

Aims: The occurrence of bacterial disease in shrimp ponds is a major problem faced in shrimp farming. Thus, the aims of this study were to isolate and evaluate antibiotic resistant profile of Vibrio harveyi strain isolated from shrimp pond water, as well as to study the potential anti-Vibrio activity of Combretum quadrangulare Kurz. (CQ) and Mimosa pudica (MP) leaves extracts. Methodology and results: Vibrio harveyi WSC103 was isolated from water in white shrimp (Litopenaeus vannamei) culture pond and identified using 16S rRNA gene sequencing analysis. This strain showed characteristics of multidrug-resistant (7 antibiotics). It had become more sensitive to antibiotics (9 out of 10 antibiotics) after plasmid curing. It is showed CQ and MP leaves extracts contain potent bioactive compounds (tannins, flavonoids, steroids, cardiac glycosides and alkaloids) against V. harveyi WSC103. The aqueous, 95% ethanolic and 75% acetone extracts of CQ (MIC value of 3.13-12.50 mg/mL) and MP (MIC value of 3.13-25.00 mg/mL) leaves revealed strong vibriostatic activity, but aqueous and 95% ethanolic extracts in both plants showed vibriocidal activity. The 95% ethanolic extract of both CQ and MP leaves displayed the excellent vibriocidal property with MBC value of 100 mg/mL with zone of inhibition at 11.44 ± 1.01 and 11.78 ± 1.01 mm by agar disc diffusion. Conclusion, significance and impact of study The isolated Vibrio harveyi WSC103 was successfully characterized as a novel multidrug-resistant strain. The ethanolic C. quadrangulare Kurz. and M. pudica extracts exhibited prominent vibriostatic and vibriocidal capacities. These finding is proven that C. quadrangulare Kurz. and M. pudica extracts would be an alternative anti-Vibrio agent for aquaculture infectious treatment.
Vibrionaceae ; Gram-Negative Bacteria ; Combretum ; Mimosa

The targeting of anti-tumor drugs is an important means of tumor treatment and reducing drug side effects. Oxygen-depleted hypoxic regions in the tumour, which oxygen consumption by rapidly proliferative tumour cells, are generally resistant to therapies. Magnetotactic bacteria (MTB) are disparate array of microorganism united by the ability to biomineralize membrane-encased, single-magnetic-domain magnetic crystals (magnetosomes) of minerals magnetite or greigite. MTB by means of flagella, migrate along geomagnetic field lines and towards low oxygen concentrations. MTB have advantage of non-cytotoxicity and excellent biocompatibility, moreover magnetosomes (BMs) is more powerful than artificial magnetic nanoparticles(MNPs). This review has generally described the biological and physical properties of MTB and magnetosomes, More work deals with MTB which can be used to transport drug into tumor based on aerotactic sensing system as well as the competition of iron which is a key factor to proliferation of tumor. In addition, we summarized the research of magnetosomes, which be used as natural nanocarriers for chemotherapeutics, antibodies, vaccine DNA. Finally, We analyzed the problems faced in the tumor treatment using of MTB and bacterial magnetosomes and prospect development trends of this kind of therapy.
Bacteria ; Ferrosoferric Oxide ; Gram-Negative Bacteria ; Magnetics ; Magnetosomes ; Neoplasms/therapy*

Antibacterial activity of EA, a preparation of water soluble components made from carpophores of Elfvingia applanata (Pers.) Karst, was examined by macrobroth diltution method against a number of bacterial species. Antibacterial effects of EA were expressed as minimal inhibitory concentration (MIC) for growth. Among twelve species of bacteria tested, six strains of each gram positive bacteria and gram negative bacteria, EA showed the most potent antibacterial activity against Staphylococcus epidermidis and Proteus vulgaris, of which MICs were 1.25 mg/ml of EA. To investigate the antibacterial effects of combinations of EA with third generation cepholosporins, such as cefotaxime, ceftriaxone, ceftazidime, and cefixime, the fractional inhibitory concentration (FIC) and fractional inhibitory concentration index (FICI) were determined by macrodilution checkerboard assay for twelve bacterial strains. Combinations of EA and third generation cephalosporins exhibited either additive or indifferent effects in most instances. However, synergistic effects were observed in six instances. No antagonistic effect was observed in any cases.
Bacteria ; Cefixime ; Cefotaxime ; Ceftazidime ; Ceftriaxone ; Cephalosporins* ; Gram-Negative Bacteria ; Gram-Positive Bacteria ; Proteus vulgaris ; Staphylococcus epidermidis

Extracellular vesicles (EVs), also known as membrane vesicles, are vesicular bodies secreted by eukaryotic cells and bacteria. EVs can carry proteins, DNA, RNA, and various metabolites for the exchange and transmission of substances between cells. They play contents-dependent physiological functions, such as delivering nutrients, participating in immune response, and treating cancers. Currently, most studies focus on the exploration of vesicles secreted by eukaryotic cells and gram-negative bacteria, while few studies focus on gram-positive bacteria. This review summarized the production, content composition, physiological function, and engineering of EVs secreted by gram-positive bacteria, and prospected future perspectives in this area.
Bacteria/metabolism* ; Extracellular Vesicles/metabolism* ; Gram-Negative Bacteria ; Gram-Positive Bacteria/metabolism* ; Proteins/metabolism*