In Vitro Antibiotic Sensitivity of Oral Microorganisms to Actinobolin

1970 ◽  
Vol 49 (1) ◽  
pp. 137-139 ◽  
Author(s):  
D.E. Hunt ◽  
H.J. Sandham ◽  
R.C. Caldwell
1970 ◽  
Vol 1 (4) ◽  
pp. 82-88 ◽  
Author(s):  
MJ Foysal ◽  
MM Rahman ◽  
M Alam

Studies were conducted to identify Pseudomonas fluorescens isolates from a collection of bacteria isolated from bacterial haemorrhagic septicaemia infected carp and catfish, evaluate their antibiotic sensitivity pattern and screen the antibacterial activity of some medicinal plant extracts against the isolates.. A total of 10 isolates were identified as P. fluorescens by morphological, physiological and biochemical tests. In vitro antibiotic sensitivity test of the P. fluorescens isolates were conducted by disc diffusion method for seven antibiotics where, all of the isolates were found to be sensitive only against streptomycin and gentamycin but, most of the isolates (80%) were found resistant to chloramphenicol (C). Moreover, eighty percent of the isolates showed resistance to multiple antibiotics. A total of 118 plant extracts were screened for their antibacterial activity against the P. fluorescens isolates where the isolates exhibited sensitivity to 30 samples. Leaf extracts of Tamarindus indicus, Terminalia chebula, Citrus aurantifolia, Eugenia caryophyllata and Spondias pinnata were found to inhibit the growth of all of the P. fluorescens isolates. DOI: http://dx.doi.org/10.3329/ijns.v1i4.9733 IJNS 2011 1(4): 82-88


2017 ◽  
Vol 37 (3) ◽  
pp. 342-344
Author(s):  
Roberta M. Katzap ◽  
Vany Elisa Pagnussatti ◽  
Ana Elizabeth Figueiredo ◽  
Julia Gabriela Motta ◽  
Domingos O. d'Avila ◽  
...  

Patients with chronic kidney disease on peritoneal dialysis (PD) are susceptible to infections, with peritonitis being the primary cause of dropout. Peritoneal fluid culture is one of the essential elements for proper diagnosis and peritonitis treatment. The aim of this study was to compare the time required to obtain a positive culture using different laboratory methods. An in vitro cross-sectional study was conducted comparing different techniques for preparation and culture of bacteria in peritoneal fluid. The research was carried out with 21 sterile dialysis bags and 21 PD bags containing peritoneal fluid drained from patients without peritonitis. Fluids from the 42 PD bags were contaminated by injecting a coagulase-negative Staphylococcus suspension and then prepared for culture using 4 distinct techniques: A - direct culture; B - post-centrifugation culture; C - direct culture after 4 h sedimentation; and D - culture after 4 h sedimentation and centrifugation. This was followed by seeding. In the 21 contaminated sterile bags, mean times to obtain a positive culture with techniques D (19.6 h ± 2.6) and C (19.1 h ± 2.3) were longer than with technique A (15.8 h ± 3.0; p < 0.01), but not statistically different from group B (19.0 h ± 3.2). The same occurred in the 21 bags drained from patients, with mean times for techniques D (14.0 h ± 1.9) and C (14.5 h ± 1.7) being longer than technique A (12.22 h ± 1.94; p < 0.05) but not statistically different from technique B (13.2 h ± 1.3). The sedimentation and centrifugation steps seem to be unnecessary and may delay antibiotic sensitivity test results by approximately 8 hours.


Microbiology ◽  
2014 ◽  
Vol 160 (10) ◽  
pp. 2157-2169 ◽  
Author(s):  
Sudarson Sundarrajan ◽  
Junjappa Raghupatil ◽  
Aradhana Vipra ◽  
Nagalakshmi Narasimhaswamy ◽  
Sanjeev Saravanan ◽  
...  

P128 is an anti-staphylococcal protein consisting of the Staphylococcus aureus phage-K-derived tail-associated muralytic enzyme (TAME) catalytic domain (Lys16) fused with the cell-wall-binding SH3b domain of lysostaphin. In order to understand the mechanism of action and emergence of resistance to P128, we isolated mutants of Staphylococcus spp., including meticillin-resistant Staphylococcus aureus (MRSA), resistant to P128. In addition to P128, the mutants also showed resistance to Lys16, the catalytic domain of P128. The mutants showed loss of fitness as shown by reduced rate of growth in vitro. One of the mutants tested was found to show reduced virulence in animal models of S. aureus septicaemia suggesting loss of fitness in vivo as well. Analysis of the antibiotic sensitivity pattern showed that the mutants derived from MRSA strains had become sensitive to meticillin and other β-lactams. Interestingly, the mutant cells were resistant to the lytic action of phage K, although the phage was able to adsorb to these cells. Sequencing of the femA gene of three P128-resistant mutants showed either a truncation or deletion in femA, suggesting that improper cross-bridge formation in S. aureus could be causing resistance to P128. Using glutathione S-transferase (GST) fusion peptides as substrates it was found that both P128 and Lys16 were capable of cleaving a pentaglycine sequence, suggesting that P128 might be killing S. aureus by cleaving the pentaglycine cross-bridge of peptidoglycan. Moreover, peptides corresponding to the reported cross-bridge of Staphylococcus haemolyticus (GGSGG, AGSGG), which were not cleaved by lysostaphin, were cleaved efficiently by P128. This was also reflected in high sensitivity of S. haemolyticus to P128. This showed that in spite of sharing a common mechanism of action with lysostaphin, P128 has unique properties, which allow it to act on certain lysostaphin-resistant Staphylococcus strains.


PEDIATRICS ◽  
1959 ◽  
Vol 24 (1) ◽  
pp. 40-42
Author(s):  
Fred E. Pittman ◽  
Calderon Howe ◽  
Louise Goode ◽  
Paul A. di Sant'Agnese

In this study, 198 strains of hemolytic, coagulase-positive Staph. aureus were recovered from 84 patients with cystic fibrosis of the pancreas and some of their relatives. The majority of the organisms fell into phage group III and were resistant in vitro to penicillin and other antibiotics. No single phage type seemed to be unduly prevalent in this group of patients with cystic fibrosis of the pancreas.


PEDIATRICS ◽  
1958 ◽  
Vol 21 (4) ◽  
pp. 609-623
Author(s):  
Charles V. Pryles

Staphylococcal pneumonia appears to be increasing in frequency and is a particularly important problem in early infancy when the disease tends to be specially severe and may prove fatal. Only early recognition and prompt treatment can reduce the high mortality rate in this age group. A high index of suspicion must exist for this type of pneumonia in any infant who presents with signs or symptoms of infection of the lower respiratory tract and who fails to respond to adequate doses of penicillin or one of the cyclines in a period of 24 to 36 hours. Frequent and careful observations of any such infant to detect the appearance of empyema fluid and, more particularly, tension pneumothorax are vitally important. Once the presence of empyema has been established, prompt and effective drainage with a closed system should, in our opinion, be instituted without delay; it is also our feeling that the local administration of an antibiotic, such as bacitracin, may be useful and we recommend its use in this manner. Chloramphenicol and erythromycin, used together, in an effort to delay the emergence of resistant organisms, are the antibiotics of choice in the treatment of pneumonia due to penicillin-resistant strains of staphylococci. In view of our experience with this disease, we recommend therapy as follows: All infants with a tentative diagnosis of staphylococcal pneumonia who have not received any prior antibiotic therapy should receive penicillin, erythromycin and chloramphenicol immediately after cultures are obtained; then administration of the antibiotic or antibiotics shown by in vitro tests to be least effective against the strain of staphylococcus causing the disease, is discontinued. If the patient has been receiving penicillin prior to admission to the hospital and history shows no evidence of response or improvement, one may infer that the organism is pencillin-resistant and chloramphenicol and erythromycin alone are given. While triple therapy of this condition may not be ideal, the employment of this combination is considered justified until a satisfactory etiologic diagnosis can be obtained or until antibiotic sensitivity tests are completed. Dowling and his colleagues agree with such therapy in principle especially in the treatment of serious staphylococcal infections, and state that antibiotics when used under such circumstances, as outlined above, "should be used in full (italics ours) doses," and we should like to emphasize the importance of this principle. Satisfactory clinical evidence of antagonism among antibiotics is lacking and most authorities agree that antagonism between antibiotics "is of little or no consequence in the management of human infections." While some admit the possibility that antagonism may exist occasionally, they feel this is a rare phenomenon. When satisfactory evidence becomes available that there is antagonism among these three antibiotics in the treatment of staphylococcal infections, our present recommendations will be altered but until such time the triple combination is urged in view of the fact that this infection progresses extremely rapidly and every hour counts. Finally, antibiotics must not be discontinued too early, but should be administered for an average period of 2 to 3 weeks after the patient has become afebrile, or until all signs and symptoms of active disease have disappeared. The use of a potent bactericidal agent such as bacitracin locally may be extremely important in a severely ill infant with empyema. It is our practice at present in patients with empyema to instill 5,000 to 10,000 units of bacitracin at the time of the initial thoracentesis.


1981 ◽  
Vol 87 (3) ◽  
pp. 339-355 ◽  
Author(s):  
S. Helgason ◽  
D. C. Old

SummaryAn epidemiological study of Sonne dysentery in Dundee during the years 1971–6 was made by examining, in respect of 1420 isolates ofShigella sonnei, the discriminating power of colicine typing, antibiogram testing, biotyping and resistotyping and the stability of the markers they provided.Colicine typing identified nine colicine types, including four not previously described. However, because types 4 and 4 var., determined bycolIb, and type U, producing no colicines, accounted for 96 % of the isolates, discrimination with colicine typing was poor. In antibiotic sensitivity tests, 13 different antibiogram patterns were noted. Less than 1 % of the isolates were sensitive to all of the eight antibiotics tested; most were multiply drug-resistant. Resistance to kanamycin, neomycin and paromomycin (KNP) was apparently due to a single resistance determinant, widely distributed in a majority (53%) of the isolates. When definitive times were chosen for reading each biotyping test, only maltose and rhamnose of the 13 ‘sugars’ tested differentiated isolates into prompt- and late-fermenting types. Though the ability to ferment rhamnose was a stable property, it discriminated only 1·5% of the minority, late-fermenting type. Resistotyping with six chemicals discriminated eight epidemiologically valid resistotypes, including three new types. However, 93 % of the isolates belonged to only three resistotypes.Analysis of the data for isolates from 286 epidemiologically distinct episodes showed that the variability of colicine and antibiogram characters, found among isolates within, respectively, 40 and 28 % of the episodes, was generally associated with loss or gain of a plasmid (‘colIb-KNP’) which determined production of colicine Ib and KNP resistance. These characters varied bothin vivoandin vitro. Variability of resistotype characters, on the other hand, was observed in only 28 (9%) episodes, 14 of which possibly represented examples of mixed or sequential infections.For accurate epidemiological tracing of strains ofSh. sonneiin a community, resistotyping, the technique showing the greatest discrimination and least variability of the four tested, should be included as the principal typing method.


Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 599
Author(s):  
Olga Radulović ◽  
Slaviša Stanković ◽  
Branka Uzelac ◽  
Vojin Tadić ◽  
Milana Trifunović-Momčilov ◽  
...  

The main topic of this study is the bioremediation potential of the common duckweed, Lemna minor L., and selected rhizospheric bacterial strains in removing phenol from aqueous environments at extremely high initial phenol concentrations. To that end, fluorescence microscopy, MIC tests, biofilm formation, the phenol removal test (4-AAP method), the Salkowski essay, and studies of multiplication rates of sterile and inoculated duckweed in MS medium with phenol (200, 500, 750, and 1000 mg L−1) were conducted. Out of seven bacterial strains, six were identified as epiphytes or endophytes that efficiently removed phenol. The phenol removal experiment showed that the bacteria/duckweed system was more efficient during the first 24 h compared to the sterile duckweed control group. At the end of this experiment, almost 90% of the initial phenol concentration was removed by both groups, respectively. The bacteria stimulated the duckweed multiplication even at a high bacterial population density (>105 CFU mL−1) over a prolonged period of time (14 days). All bacterial strains were sensitive to all the applied antibiotics and formed biofilms in vitro. The dual bacteria/duckweed system, especially the one containing strain 43-Hafnia paralvei C32-106/3, Accession No. MF526939, had a number of characteristics that are advantageous in bioremediation, such as high phenol removal efficiency, biofilm formation, safety (antibiotic sensitivity), and stimulation of duckweed multiplication.


2018 ◽  
Vol 28 (1) ◽  
pp. 99-108 ◽  
Author(s):  
Mohammad Ali ◽  
Shefali Boonerjee ◽  
Mohammad Nurul Islam ◽  
Mihir Lal Saha ◽  
M Imdadul Hoque ◽  
...  

The endogenous bacterial contamination of plant tissue culture materials and their possible control was studied. Nine bacterial isolates were isolated from the contaminated tissue culture materials viz. potato and tea. On the basis of morphology and biochemical characters of nine isolates, seven were identified as Gram positive belonging to Bacillus alcalophilus, B. circulans, B. infantis, B. lentus, B. schlegelii, B. pumilus and B. subtilis. Remaining two were Gram negative and identified as Enterobacter cloacae sub. sp. dissolvens and Pantoea agglomerans. Molecular analysis was conducted on the basis of 16S rDNA sequence to confirm three isolates. Culture and sensitivity test was carried out to screen out the antibiotic sensitivity where streptomycin (S-10), polymyxin (PB-300) and gentamicin (CN-120) antibiotics were found to be effective against all bacterial isolates. The culture and sensitivity test reflected the feasibility to control or eliminate the contaminant bacteria during in vitro culture of plant which is very much required in the commercial tissue culture production.Plant Tissue Cult. & Biotech. 28(1): 99-108, 2018 (June)


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