scholarly journals EFFECT OF SILICATE ON GRAM STAINING AND VIABILITY OF PNEUMOCOCCI AND OTHER BACTERIA

1956 ◽  
Vol 103 (4) ◽  
pp. 453-463 ◽  
Author(s):  
Colin M. MacLeod ◽  
Amy S. Roe

Application of silicate solutions to living or heat-killed pneumococci and to certain "viridans" streptococci causes their conversion from a Gram-positive to a Gram-negative state. The original staining properties can be restored by suspending the silicate-treated bacteria in alkaline solutions of various salts but not by simple washing in water. Living pneumococci and the strains of streptococci whose staining properties are similarly affected are killed when suspended in silicate solutions. In other Gram-positive species silicate causes conversion to Gram negativity but restoration to positivity occurs upon washing in water. In a third group of Gram-positive organisms silicate has no effect on the Gram reaction. The viability of organisms in these two groups is unaffected by silicate under the conditions employed. No effect on staining or viability of Gram-negative bacteria has been observed. The effects of silicate on staining and viability are inhibited by nutrient broth or whole serum but not by purified serum albumin. Lecithin, choline, and other substituted ammonium compounds also inhibit the effects of silicate on pneumococci.

2019 ◽  
Vol 25 (5) ◽  
pp. 502-507 ◽  
Author(s):  
Zenith Khashim ◽  
Seán Fitzgerald ◽  
Ramanathan Kadirvel ◽  
Daying Dai ◽  
Karen M Doyle ◽  
...  

Background Bacteria and bacterial components have been associated with the activation of coagulation factors and initiating the blood clot formation. The aim of this study was to investigate whether bacterial populations are present in clots retrieved from patients that have suffered a large vessel occlusion acute ischemic stroke (AIS). Materials and methods Clot samples were collected from 20 AIS patients who underwent clot retrieval with mechanical thrombectomy. Patient clinical demographic details were noted. Expression of bacterial 16S rDNA was analyzed by standard and real-time polymerase chain reaction (PCR). Gram staining was performed to identify Gram-positive and Gram-negative bacteria. Results Both the real-time and standard PCR demonstrated no expression of 16S rDNA in any of the 20 clots samples from AIS patients. Gram staining results showed no expression of Gram-positive or Gram-negative bacteria present in the clot samples. Conclusion Our current study found no bacteria populations in the clots of AIS patients.


2021 ◽  
Author(s):  
lydiariver not provided

Gram staining is one of the first techniques used for the identification of group B Streptococcus agalactiae and one would expect to see gram-positive cocci under the microscope. The technique consists of applying a series of colorants and bleaches (acetone), which interact with the lipids of the membranes of gram-positive and gram-negative bacteria. The cell walls of gram-positive organisms retain the dye after acetone treatment and appear purple in color, whereas gram-negative organisms become discolored after acetone treatment and appear pink.


e-CliniC ◽  
2014 ◽  
Vol 2 (1) ◽  
Author(s):  
I Made Dwi Pramana

Abstract: Background: Bacterial infection is one of the causes of diarrhea in infants and children. Bacteria are a group of microorganisms belongs to the prokaryotes which are structurally simpler than eukaryotics. There were many examinations used to detect the bacteria caused diarrhea, one of them was microscopic examination of the Gram stain smear. This technique is to determine whether the examination is Gram positive or Gram negative bacteria. Objective: This study aimed to determine the pattern of bacteria by Gram stain in children’s feces with diarrhea. Methods: This research used a descriptive designed with cross sectional approach by consecutive sampling from November to December 2013. There were 50 children in this study. Result: The results showed, 29 girls (58%) and 21 boys (42%). There were 34 children (68%) as the largest group that belongs to 1 - <3 years old. The results of feces microscopic examination showed 29 children (58%) got contaminated by bacteria. 23 children (46%) were contaminated with Gram positive and Gram negative bacteria. Gram negative Basil bacteria ware the most common bacteria that found in 23 preparations. Conclusion: Gram-negative bacilli germ were the most common germs that found in children’s feces with diarrhea and the numbers of diarrhea on November to December 2013 were increased. Key words: bacterial pattern, Gram staining, children, diarrhea  Abstrak: Latar belakang: Infeksi bakteri merupakan salah satu penyebab terjadinya diare pada bayi dan anak. Bakteri merupakan mikroorganisme yang termasuk dalam golongan prokariot yang strukturnya lebih sederhana dari eukariot. Banyak pemeriksaan yang dilakukan untuk mendeteksi bakteri penyebab diare, salah satunya dengan pemeriksaan mikroskopis pulasan yaitu pewarnaan Gram yang merupakan salah satu teknik pemeriksaan untuk menentukan apakah termasuk bakteri Gram positif atau bakteri Gram negatif. Tujuan penelitian: Penelitian ini bertujuan unutk mengetahui pola kuman berdasarkan pewarnaan Gram pada tinja anak dengan diare. Metode: Penelitian ini menggunakan desain penelitian deskriptif dengan pendekatan cross sectional yang dilakukan dengan cara consecutive sampling dari bulan November sampai Desember 2013. Sampel penelitian berjumlah 50 anak dan dilakukan pemeriksaan pewarnaan Gram. Hasil penelitian: Hasil penelitian didapatkan, perempuan 29 anak (58%) dan Laki-laki 21 anak (42%). Kelompok umur terbanyak 1 ─ <3 berjumlah 34 anak (64%). Hasil pemeriksaan mikroskopis feses ditemukan positif bakteri sebanyak 29 anak (58%). Bakteri Gram positif dan Gram negatif didapatkan berjumlah 23 anak (46%). Bakteri Basil Gram negatif merupakan bakteri terbanyak yang ditemukan yaitu 23 preparat. Kesimpulan: Kuman basil Gram negatif merupakan kuman terbanyak yang ditemukan pada tinja anak dengan diare dan terjadi peningkatan angka kejadian diare pada bulan November – Desember 2013. Kata kunci : pola kuman, pewarnaan Gram , anak, diare


Author(s):  
Pratirodh Koirala ◽  
Dwij Raj Bhatta ◽  
Prakash Ghimire ◽  
Bharat Mani Pokhrel ◽  
Upendra Devkota

The tracheostomized patients are colonized mostly by gram negative bacteria which lead to either tracheobronchitis or bronchopneumonia. This study was conducted to isolate and identify the potential pathogen causing post tracheostomy infection. A cross-sectional study was conducted during April 2008 to February 2009 based at Neuro Center, Kathmandu. Tracheal aspirates of 50 patients having fever more than 38°C were collected and analyzed for bacterial content. Out of the 50 cases, 45(90%) cases showed bacterial growth. Sixty-seven isolates were identified; with 20(44.4%) poly-microbial cases. Pseudomonas aeruginosa and enteric gram negative bacteria were predominant bacteria (n=27, 40.3%) followed by Staphylococcus aureus (n=7, 10.4%), other Gram negative bacteria (n=4, 5.9%) and Viridans Streptococci (n=2, 2.9%). Pseudomonas aeruginosa were most sensitive to the Amikacin (n=22, 81.4%) and Ciprofloxacin (n=19, 70.3%). All Pseudomonal isolates were resistant to the Cefotaxime. Enteric Gram Negative bacteria (EGNB) were most sensitive to Amikacin and Chloramphenicol (20, 74.0%) and all were resistant to Ampicillin and Cephalexin. All the gram positive bacteria isolated were sensitive to Vancomycin. Among the total isolates, 24 (88.8%) of Pseudomonas aeruginosa, 21 (66.6%) of enteric gram negative bacteria, and 5 (55.5%) of Gram positive bacteria were multidrug resistant (MDR). The study reported alarming condition of MDR in tracheal aspirates. So surveillance for source of multidrug resistant bacteria would be beneficial for intervention of infection related to it. Key words: Tracheal aspirates, polymicrobial growth, Multidrug resistant bacteria (MDR)10.3126/ijls.v4i0.3496International Journal of Life Sciences Vol.4 2010 pp.60-65


1962 ◽  
Vol 8 (1) ◽  
pp. 99-103
Author(s):  
B. B. Diena ◽  
R. Wallace ◽  
L. Greenberg

A simple method for differentiation of bacteria parallel to Gram staining is described, using vital staining with blue tetrazolium, decolorizing the preparation with a 1:1 mixture of acetone – ethylene tetrachloride for 4 hours, and counterstaining it with carbol fuchsin. Gram-negative bacteria are decolorized while the Gram-positive ones (except B. cereus) retain their formazan. Similar results were obtained by decolorizing vitally stained bacteria with organic solvents by chromatography.


1952 ◽  
Vol 30 (1) ◽  
pp. 86-105
Author(s):  
Roland Fischer ◽  
P. Larose

The relations previously found to exist between the bactericidal activity of substances and their affinity for wool have been used as the basis for a further study of the similarity between Gram-negative bacteria and intact wool on the one hand, and between Gram-positive bacteria and degraded wool on the other. A porrespondence in behavior has been shown to exist in the case of Gram-staining, of the Eisenberg–Gutstein techniques, and of the Feulgen reaction. It was possible to produce with degraded wool a conversion from a Gram-positive state to a Gram-negative one (corresponding to that of intact wool) just as it is possible to carry out the similar conversion with Gram-positive bacteria by using oxidizing and/or acidic agents. Reconversion to the original Gram-positive state was also shown to be possible with reducing and/or alkaline agents. A mechanism is offered to explain the above findings and the respective cytochemical reactions characteristic of the cytoplasmic membrane of the bacteria. This mechanism is based on similarities in composition and structure (α-keratin) between the cytoplasmic membrane of Gram-positive bacteria and degraded wool, and the “cytoplasmic membrane” of Gram-negative bacteria and intact wool. Further possible similarities are pointed out. A new definition for bactericidal action is given in the light of these results. A direction for future work is indicated and discussed.


Author(s):  
Karamoko Detto ◽  
Fagbohoun Jean Bedel ◽  
Moroh Jean-Luc Aboya ◽  
Ouattara Gnénépari Odjo Mahoua ◽  
Djè Koffi Marcellin

The aim of this study is to evaluate some microbiological and physicochemical parameters during the production of artisanal beer based on honey and beeswax. Samples were collected at various critical points during the production process. The load of mesophilic aerobic germs and yeasts remains high during production. A total absence of lactic acid bacteria is observed in both types of beer during production. Moreover, Gram staining made it possible to isolate for wax beer, 26% of the Gram negative bacteria of which only one (1) is rod-shaped (5%) and (4) strains are hulls (21%) and 74% of the Gram positive bacteria of which three (3) strains are rods (16%) and eleven (11) strains are hulls (58%). For honey beer, 45% of the Gram-negative bacteria were isolated, of which seven (7) strains are hulls (32%) and three (3) strains are rods (13%), and 55% Gram-positive bacteria, of which seven (7) strains are hulls (32%) and five (5) strains are rods (23%). Wax and honey beers contain a high level of reducing sugars at the beginning of exploitation. During the heat treatment, the reducing sugars reduce the microorganisms disappear after 9 min and 11 min heat treatment respectively for wax and honey beer.


2019 ◽  
Vol 36 (2) ◽  
pp. 238
Author(s):  
Clara Ajeng Artdita ◽  
Fajar Budi Lestari ◽  
Achmad Fauzi ◽  
Erian Pemila Ayu Tanzila

Klebsiella spp. is a common bacteria causing mastitis. Klebsiella pneumoniae and Klebsiella varicola is the most infected Klebsiella spp in the dairy farm. This study used 16 milk samples from 8 lactation goats in Sahabat Ternak farm, Sleman, Yogyakarta. Samples were tested by california mastitis test (CMT) reagent to determine the mastitis status, inoculated on blood agar (BA) then on Mac Conkey Agar (MCA) as a selective media for Gram negative bacteria. The colonies from BA and MCA were stained by Gram staining to determine Gram-positive or Gram-negative bacteria and its cell morphology. The colonies from MCA were identified by biochemical tests such as sugar fermentation tests (glucose, lactose, maltose, and saccharose), arginine, ornithine decarboxylase, indole, citrate, urea hydrolysis (Christensen’s method), lysin and malonate. The result of mastitis test showed 5 goats were positive result and 3 samples were negative. Bacterial staining showed 2 samples were Gram-negative, rods and the others were Gram-positive, coccus. The samples with rods shapes were continued by biochemical tests. The characterization result of biochemical test indicated that the rods shapes bacteria were Klebsiella pneumoniae. These bacteria identification conducted in Laboratorium Preklinis Program Studi Kesehatan Hewan, Sekolah Vokasi Universitas Gadjah Mada and the result confirmation using positive control of  Klebsiella pneumoniae conducted in Balai Laboratorium Kesehatan Yogyakarta. These results showed that milk from Etawah crossbreed goat was infected by Klebsiella pneumoniae.


Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.


Author(s):  
Jacob S. Hanker ◽  
Dale N. Holdren ◽  
Kenneth L. Cohen ◽  
Beverly L. Giammara

Keratitis and conjunctivitis (infections of the cornea or conjunctiva) are ocular infections caused by various bacteria, fungi, viruses or parasites; bacteria, however, are usually prominent. Systemic conditions such as alcoholism, diabetes, debilitating disease, AIDS and immunosuppressive therapy can lead to increased susceptibility but trauma and contact lens use are very important factors. Gram-negative bacteria are most frequently cultured in these situations and Pseudomonas aeruginosa is most usually isolated from culture-positive ulcers of patients using contact lenses. Smears for staining can be obtained with a special swab or spatula and Gram staining frequently guides choice of a therapeutic rinse prior to the report of the culture results upon which specific antibiotic therapy is based. In some cases staining of the direct smear may be diagnostic in situations where the culture will not grow. In these cases different types of stains occasionally assist in guiding therapy.


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