Negative Microbes Research Articles

Studies on Benzothiazolo‐asycyanino‐colorants Synthesis, Structural Correlation with UV Absorption Maxima and Bactericidal Potentiality

AbstractFifteen new chromophoric chain β‐aryl substituted butadienyl‐benzothiazole asy‐cyanine colorants are synthesized by condensing substituted 3‐isopropylbenzothiazolium iodides and 4‐dimethylaminostyrylphenyl ketones using alkaline ethanolic DMF solution. The colorants show bathochromic shifts in comparison with unsubstituted analogues and styryl analogues but hypsochromic shifts when compared to 3‐methylbenzothiazolium analogues. The highly purified samples are screened in vitro against gram positive and gram negative microbes using Disc diffusion technique and found to be mildly active against some of them.

Risk Factors and Neonatal Group B Streptococcal Disease in Abu Dhabi, United Arab Emirates

The Group B streptococcus (GBS) has superseded the Gram negative microbes as the leading cause of early sepsis in the newborn period in the developed world. However dissimilarities in the rate of early onset group B streptococcal disease (EOGBSD) has led to differences in strategy in the management of the mother colonized with GBS. To provide data on the prevalence of EOGBSD a retrospective review was undertaken. In addition risk factors for disease were identified and a relative risk for disease was calculated. The cohort consisted of liveborn infants with a positive ear swab for GBS born between June 1996 and December 31 1998 comprise the study participants. Overall findings showed that 13 infants of the 22565 live inborn infants over the 2.5-year-period had proven and 29 had probable of EOGBSD. The overall prevalence of EOGBSD was 1.86/1000 live births; prevalences of proven and probable disease were 0.57/1000 and 1.29/1000 respectively. The study also showed that 30 of the 42 infants (71.4%) had 1 or more risk factors such as with prolonged rupture of membranes >18 hours maternal fever > or = 38 degrees Celsius preterm delivery <37 weeks gestation and a sibling with previous GBS sepsis. It is noted that the estimated risk for symptomatic disease was three times greater (relative risk) 3.2) when 1 or more risk factors were present.

Endogenous bacterial endophthalmitis : An East Asian experience and a reappraisal of a severe ocular affliction

Purpose To report 32 eyes of 27 patients with endogenous bacterial endophthalmitis seen over a 4 year period. Features and outcomes of this condition in the current series and the cases reported in the literature from 1986–1998 were reviewed. Design Retrospective noncomparative case series. Participants All patients with this condition seen at the three participating general hospitals were included. Intervention A review of the systemic and ocular characteristics, therapeutic methods, and final outcomes in patients afflicted with this condition. Main outcome measures Features studied included patients’ demographic characteristics, microbiology, source of infection, ocular features, therapeutic interventions, final visual and anatomic outcomes. Results Nineteen (70%) of the 27 incriminating organisms in this case series were gram negative microbes, with Klebsiella pneumoniae infections alone being responsible in 16 (60%) cases. Hepatobiliary tract infection was the source of bacteremia in 13 (48%) patients. Only nine (28%) eyes obtained good final visual acuity (20/120 or better), and two eyes were enucleated/eviscerated. A literature review of 209 patients with endogenous endophthalmitis over a 12 year period showed a similar increase in the frequency of gram negative microbes as the responsible organism, especially among the East Asian population. Overall, 22% had bilateral involvement; two thirds of patients had predisposing factor(s) or underlying illness(es), and diabetes mellitus was present in 46%. Thirty-four percent of all eyes obtained counting finger or better final vision, and 16% had their eyes eviscerated or enucleated. Infections with virulent organisms (gram negative rods, Serratia, Bacillus) usually denoted a grave visual prognosis; however, a media that was not opaque on presentation was usually associated with a good prognosis. Conclusion Metastatic ocular infection is not uncommon despite the availability of modern antibiotic therapy. Among the East Asian population, the patient at highest risk is a diabetic patient with Klebsiella pneumoniae hepatobiliary infection. In contrast, in the Caucasian population, this condition occurs in predisposed patients with gram-positive bacteremia arising from endocarditis or skin/joint infections. The final visual outcome in patients with endogenous bacterial endophthalmitis in the recent 12 years has not differed significantly from five decades ago.

Colonisation of seedling roots by 2,4‐D degrading bacteria: A plant‐microbial model

AbstractThe development of model plant‐microbial associations between Gram negative soil microbes capable of degrading phenoxyacetate herbicides, such as 2,4‐D and 2,4‐D methyl ester, and the crops canola and wheat was described. Both an Acinetobacter baumannii pJP4 transconjugant and Alcaligenes eutrophus JMP 134 colonised non‐parasitically on the roots of sterilised seedlings in a hydroponic system. Laser scanning confocal microscopy has shown that colonisation occurred both on the root surface and deeper inside the mucilage layer or inside some surface root cells. When 2,4‐D was added to the hydroponic medium supporting the growth of those seedlings colonised by 2,4‐D degrading bacteria, the gas chromatographic analysis showed a rapid decrease in the concentration of this herbicide. These bacteria colonising the root system were shown to be responsible for the degradation of 2,4‐D. Plants inoculated with the 2,4‐D degrading microbes were subsequently found to be less susceptible to damage by the herbicide in such hydroponic systems.

The study of bacteriostatic and chemotherapeutic action of the antituberculous preparation 1314 and its chlorhydrate

The authors conducted an experimental study of the bacteriostatic and chemotherapeutic effect of the autituberculous preparation 1314 (thiamido-α-ethylisonicotinic acid) and its hydrochloride. The preparation appeared to be nonactive with respect to gram positive and gram negative microbes in vitro. However, it possesses a high bacteriostatic activity with respect to theMycobacteriumtuberculosis including certain strains resistant to other antibiotics. The chemotherapeutic effect of the preparation was checked on white mice with experimentally induced hematogenous tuberculosis. Daily administration of the preparations per os (1–2 mg per mouse) retards the development of tuberculosis. The same results were obtained with administration of the hydrochloride of the 1314 per os and subcutaneously in the dose of 2 mg per mouse.

A study of the bacteriostatic and chemotherapeutic activity of the new drug cycloserine

Synthetic dl-cycloserine obtained at the Institute of Pharmacology and Chemotherapy of the USSR Academy of Medical sciences was tested in experiments in vitro. It was demonstrated that this preparation has a wide antimicrobic range of action towards gram positive, as well as towards gram negative microbes, such asB. typhi abdominalis,B. paratyphi “A” et al.