Simple Gram Research Articles

Super-Electron-Donor 2-Azaallyl Anions Enable Construction of Isoquinolines.

Herein is introduced the application of "super-electron-donor"(SED) 2-azaallyl anions in a tandem reduction/radical cyclization/radical coupling/aromatization protocol that enables the rapid construction of isoquinolines. The value of this transition-metal-free method is highlighted by the wide range of isoquinoline ethyl amines prepared with good functional group tolerance and yields. An operationally simple gram scale synthesis is also conducted, confirming the scalability.

Bacteriological profile of acute exacerbations of chronic obstructive pulmonary disease

Introduction: Acute exacerbations of chronic obstructive pulmonary disease (COPD) influence the quality of life and account for considerable morbidity and mortality. Several factors contribute to the etiology of COPD exacerbations, of which infectious process poses a major risk. Knowledge about local bacteriological profile in COPD patients would help in better selection of antibiotic for empirical therapy thereby reducing emergence of drug resistance. Aim and Objectives: To determine the bacteriological profile of acute exacerbations of COPD patients admitted at NRI Medical College, Guntur. Material and Methods: All patients admitted into the hospital from January 2017 to January 2018 diagnosed to have an acute exacerbation of chronic obstructive pulmonary disease were included in the study. Sputum samples were collected prior to the initiation of antibiotic therapy and were sent for bacteriological culture and drug sensitivity. Obtained results were analysed. The procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national). Results: The study included 128 patients of whom sputum smear was positive for growth in 96 (75%) patients. Most common organism grown was Klebsiella pneumoniae (31%) followed by Pseudomonas aeruginosa (22%), Candida species (13%), Escherichia coli (9%). Other organisms isolated from culture were Staphylococcus aureus, Burkholderia cepacia, Citrobacter, Streptococcus pneumoniae, Acinetobacter, Micrococci and Enterococcus species. Simple gram’s stain identified organisms in 60% of patients. Drug sensitivity patterns revealed most of the gram positive and gram negative organisms (92%) were sensitive to piperacillin-tazobactum, cefoperazone- sulbactum combinations. Conclusion: The microbiology of acute exacerbations of COPD varies from region to region. Studies at regular intervals would assist in identifying the causative organisms thereby allowing formulati

Identification of Etiological Agents of Pyogenic Meningitis by Gram Stain Culture in the Patients Admitted in Two Hospital

Background: Bacterial meningitis is an important cause of mortality and long termmorbidity. Early and accurate diagnosis of bacterial meningitis is of criticalconcern.The bacterial meningitis epidemiological landscape is not static andetiological agent varies with age and immune status and different geographic area.A simple Gram stained smear can offer immediate clues to aid the diagnosis ofpyogenic meningitis. This study was performed to identify the causative agents ofpyogenic meningitis.
 Materials and methods: This cross sectional study was carried out in theDepartment of Microbiology, Chattogram Medical College for cytologicalexamination, biochemical tests, Gram’s stain, culture. The gold standard fordiagnosis of any infection including meningitis is the isolation and identification ofthe causative agent.
 Results: Among the 144 suspected meningitis cases, according to cytological andbiochemical findings 36 (25%) were categorized as probable bacterial meningitiscases and 68(47.22%) cases were viral meningitis, normal level of protein, glucoseand cell count were found in 40 (27.78%) cases. Among the 36 cases of probablebacterial meningitis, culture was positive in 12 (33.33%) and Gram’s stain waspositive in 9 (25%) cases. Streptococcus pneumoniae was the predominent organismdetected by isolation in 6(50%).
 Conclusion: S. pneumoniae is the predominant cause of pyogenic meningitis.
 Chatt Maa Shi Hosp Med Coll J; Vol.19 (1); January 2020; Page 24-27

The association between abnormal vaginal microbial flora and preterm labor. Does a simple Gram's stain of vaginal swab gives more useful data than culture ?


 
 
 
 Fac Med Baghdad
 2014; Vol.56, No.2
 Received: Jan., 2014
 Accepted March. 2014
 
 
 
 
 
 Background: Preterm labor is the major cause of perinatal mortality and morbidity and it is a challenging obstetrical complication as treatment is marginally effective if ever and no improvement in incidence over the last 5 decades , although may causes were identified the majority are idiopathic and in this category infection seems to be involved as a causative agent
 Objectives: to evaluate the association of abnormal vaginal flora diagnosed by direct Gram's staining and vaginal culture with preterm labor.
 Patients, material and methods: 25 women with preterm labor compared with 25 women at full term pregnancy, high vaginal swabs for direct Gram's staining (Spiegel criteria for abnormal vaginal flora) and culture. The results were compared in both group 
 Results: this study showed significant association between preterm labor and abnormal vaginal flora 7 (28%) and 12 (48%) of grade II and III respectively . and a significant association between term pregnancy and normal vaginal flora 16 (64%) of grade I. Also in the presence of abnormal vaginal flora, no significant association with type of pathogenic microorganism and preterm labor as all types may be associated with PTL , and the presence of Lactobacillus spp. (normal grade I flora ) is associated with term pregnancy.
 Conclusions: Gram's staining of high vaginal swab using Spiegel criteria can be useful simple test to predict preterm labor

Ocular Surface Infections in Northeastern State of Malaysia

Ocular surface infections that include infections of conjunctiva, adnexa, and cornea have the potential risk of causing blindness within a given population. Empirical antibiotic therapy is usually initiated based on epidemiological data of common causative agents. Thus, the aims of this study were to determine the bacterial agents and their susceptibility patterns of isolates from ocular surface specimens in our hospital. This is a retrospective analysis and records of bacterial isolates from ocular surface specimens in Hospital Universiti Sains Malaysia from January 2001 to December 2010 were examined. Specimens were processed according to standard laboratory procedures. Antimicrobial susceptibility testing was conducted based on Clinical and Laboratory Standards Institute recommendations. Only single, nonrepetitive isolates were included in the analysis. A total of 1,267 isolates were obtained during the study period, which comprised Staphylococcus aureus (n = 299, 23.6%), Pseudomonas aeruginosa (n = 194, 15.3%), Streptococcus pneumoniae (n = 108, 8.5%), Haemophilus influenzae (n = 100, 7.9%), Haemophilus parainfluenzae (n = 84, 6.6%), and Enterobacter spp. (n = 81, 6.4%). Fungi contributed to 4.4% of the total isolates. The antimicrobial susceptibility testing demonstrated that gram-positive bacteria were generally resistant to gentamicin (19%-57%), whereas gram-negative bacteria were resistant to chloramphenicol (27%-58%). Based on the above results, knowledge of the initial Gram stain findings is imperative before the commencement of empirical antibiotic therapy. Therefore, a simple Gram staining for all eye specimens is highly recommended.

Historical Use of Cover Slips for Staining Bacterial Specimens

There is probably no more universal technique in microbiology than the simple Gram stain. Early American textbooks and manuals describing bacteriological methods that were published between 1880 and 1915 consistently specified that bacteria be stained on cover slips. Many of these books provide great detail on how to prepare cover slips for staining purposes, including the use of special forceps to make the process less cumbersome. However, none explained why stains should be applied to specimens on cover slips rather than on microscope slides. Instead, the procedures described staining then heat fixing specimens on cover slips before placing each cover slip, bacteria side down, on a slide containing a drop of water and reading it with a high-power immersion lens.

Novel isosteric charge-deficient spermine analogue—1,12-diamino-3,6,9-triazadodecane: synthesis, pK a measurement and biological activity

Ionic interactions are essential for the biological functions of the polyamines spermidine and spermine in mammalian physiology. Here, we describe a simple gram scale method to prepare 1,12-diamino-3,6,9-triazadodecane (SpmTrien), an isosteric charge-deficient spermine analogue. The protonation sites of SpmTrien were determined at pH range of 2.2-11.0 using two-dimensional (1)H-(15)N NMR spectroscopy, which proved to be more feasible than conventional methods. The macroscopic pK(a) values of SpmTrien (3.3, 6.3, 8.5, 9.5 and 10.3) are significantly lower than those of 1,12-diamino-4,9-diazadodecane (spermine). The effects of SpmTrien and its parent molecule, 1,8-diamino-3,6-diazaoctane (Trien), on cell growth and polyamine metabolism were investigated in DU145 prostate carcinoma cells. SpmTrien downregulated the biosynthetic enzymes ornithine decarboxylase (ODC) and S-adenosyl-L: -methionine decarboxylase and decreased intracellular polyamine levels, whereas the effects of Trien alone were minor. Interestingly, both SpmTrien and Trien were able to partially overcome growth arrest induced by an ODC inhibitor, alpha-difluoromethylornithine, indicating that they are able to mimic some functions of the natural polyamines. Thus, SpmTrien is a novel tool to influence polyamine interaction sites at the molecular level and offers a new means to study the contribution of the protonation of spermine amino group(s) in the regulation of polyamine-dependent biological processes.

Cryptococcal meningitis with an antecedent cutaneous Cryptococcal lesion

Cutaneous cryptococcosis, caused by an encapsulated yeast, Cryptococcus neoformans, is generally associated with concomitant systemic infection. Here we report a case of primary cutaneous cryptococcosis with spread to central nervous system in an HIV seronegative young boy. In the present case, a 17-year-old boy who was suffering from a non-healing ulcer on his right great toe for 5 months, presented with the signs and symptoms of meningitis. Cryptococcus neoformans var. gattii was isolated from the CSF of the patient. Amphotericin B administration produced recovery from the meningitis as well as from the ulcer. This case study suggests that primary cutaneous cryptococcosis can be diagnosed provisionally by a simple Gram stained smear and India ink examination in order to avoid occurrence of disseminated cryptococcosis, including meningial involvement, which may have a fatal outcome.

Evaluation of a Rapid Gram Stain Interpretation Method for Diagnosis of Bacterial Vaginosis

A simple Gram stain evaluation for the diagnosis of bacterial vaginosis was assessed in comparison to Nugent's method. The sensitivity (90%), specificity (94%), positive and negative predictive values (90% and 94%), and good interobserver agreement obtained indicate that the test method can be performed reliably in the routine clinical microbiology laboratory.

Evaluation of the MicroFoss system for the detection of Listeria species in environmental samples

The MicroFoss system was evaluated for its ability to detect Listeria species in environmental samples. The sensitivity and specificity of the MicroFoss were determined in relation to a standard culture method for Listeria detection. The sensitivities of both the MicroFoss and standard culture methods were similar (88.4%—MicroFoss, 90.7%—Culture) based on the total number of positive results obtained by both methods. The MicroFoss system detected Listeria spp. in 12 samples, which were not detected by culture, and the culture method detected Listeria spp. in 15 samples, which were not detected by the MicroFoss method. This was likely due to uneven distribution of low levels of Listeria organisms in the split sponge samples used to assess the performance of these test methods. The specificity value determined for the MicroFoss system was 92.7%. The majority of microbes causing false positive results in the MicroFoss system were Bacillus species, which were readily distinguishable from Listeria species by a simple Gram stain and morphological features. Listeria monocytogenes (89.4%—MicroFoss, 88.0%—Culture) and Listeria innocua (8.8%—MicroFoss, 7.7%—Culture) were the most common isolates of Listeria detected by the two test methods, with L. monocytogenes being the most predominant isolate detected. The highly comparable results and rapid nature of the MicroFoss system demonstrate its effectiveness as a detection system for species of Listeria in environmental samples. The fact that the sensitivity of the MicroFoss system was similar to that of the culture method and the Listeria results were obtained within 48 h of testing, support the use of the MicroFoss as an alternative rapid method for screening large numbers of environmental samples for Listeria spp.

Role of Candida in indirect pathogenesis of antibiotic associated diarrhoea in infants.

One hundred and thirty seven isolates of Candida species were isolated from antibiotic associated diarrhoea cases and were examined to study the role of Candida in the pathogenesis of diarrhoea in infants. The quantitative estimation of yeast population by simple gram stain smear revealed more than 70% of the cases had 3+ score. The isolates further screened for detection of beta-lactamases. Among the isolated Candida sp, beta-lactamases was secreted by C. albicans, C. tropicalis, C. krusei and C. parapsilosis. Further, 46% of the Candida isolates were found to be produced 741-1110 mU/ml of beta-lactamases, suggesting that these enzyme would inactivate penicillin group of drugs and cause failure in the therapy directed against other diarrhoegenic bacteria.

Gonococcal Urethritis-Diagnosis and Treatment

For men with urethral discharge, a simple gram stained smear is 98% sensitive and over 99% specific in detecting gonococcal infection when compared to a single Thayer-Martin culture. The smear is less than 50% sensitive in asymptomatic urethritis. Neither Fluorescent antibody nor various serologic tests offer any diagnostic advantages over smears and/or cultures and they are not cost-effective. Treatment of gonococcal urethritis may be successfully accomplished with a variety of antibiotic regimens. Tetracycline hydrochloride (500 mg four times a day for 5 days) is highly effective, inexpensive, and is active against Chlamydia trachomatis; post gonococcal urethritis (PGU) is therefore uncommon. Aqueous Procaine Penicillin G (4.8 million units IM with 1 g of probenecid) has become the standard in the United States but suffers from higher cost, the need for refrigeration, occasional alarming toxic procaine reactions, and a high incidence of PGU. Spectinomycin 2 g IM remains expensive but is the regimen of choice for treatment failures and for Neisseria gonorrhoeae that produce penicillinase (PPNG). Other antibiotics active against PPNG are cotrimoxozole, cefoxitin, and cefuroxime. PNNG have now been reported from 27 countries throughout the world, but have attained significant prevalence in only a few areas of East Asia and West Africa. Because gonococcal patterns of antibiotic resistance are constantly changing, each region of the world needs to monitor treatment results and maintain some surveillance over sensitivity to antibiotics.