Chlamydia Trachomatis Antigen Detection by Chlamydiazyme Combined with Chlamydia Blocking Reagent Verification

1992 ◽  
Vol 3 (5) ◽  
pp. 355-359 ◽  
Author(s):  
Barbro Zeeberg ◽  
Ingrid Thelin ◽  
Claes Schalén
Keyword(s):  
Chlamydial Infection ◽  
Direct Immunofluorescence ◽  
Gram Negative Bacteria ◽  
Routine Laboratory ◽  
Laboratory Setting ◽  
Gram Negative ◽  
Increased Sensitivity ◽  
Immuno Assay ◽  
Enzyme Immuno Assay ◽  
Chlamydial Antigen

Several options exist for the detection of chlamydial infection in a routine laboratory setting. Enzyme immuno assay (EIA) technology offers rapid turn around of results and is less technically demanding than chlamydial cell culture. In addition, recently introduced EIA confirmatory reagents have the potential to improve the accuracy of EIA detection. We have evaluated one such confirmatory reagent (Chlamydia Blocking Reagent®, Abbott Laboratories) to determine the accuracy of the Chlamydiazyme® EIA with special regard to interpretation of low absorbance values. An initial series of 192 male urethral specimens showed that use of a lowered cut off level (absorbance value 0.05) compared with that recommended by the manufacturer increased sensitivity of the EIA from 0.73 to 0.83, thus motivating studies on this interpretative modification. Of 1101 EIA reactive specimens, 65% were determined to be chlamydia positive by the Chlamydia Blocking Reagent. The proportion of female cervical specimens that did not confirm positive was elevated compared with male urethral specimens, 43% vs. 5.7% respectively. In samples yielding absorbance from the recommended cut off level to 0.05 (approximately 50% below), the corresponding figures were 78% and 14% respectively. In 85 selected EIA reactive samples, examination by a direct immunofluorescence staining assay (DFA) (MicroTrak®, Syva Inc.) revealed elementary bodies in 85% of 67 blocking test positive and in 24% of 18 blocking test negative samples. The possibility that Gram-negative bacteria were responsible for unconfirmed EIA reactive specimens was investigated using bacterial suspensions. While EIA reactivity was noted with several strains for Gram-negative bacteria, both the blocking reagent and DFA correctly verified the absence of chlamydial antigen. We conclude that confirming Chlamydiazyme initial reactive samples with the Chlamydia Blocking Reagent improved the accuracy of chlamydial detection by identifying false positive specimens. Furthermore, by including confirmatory testing, a lower cut off level than recommended by the manufacturer seems applicable, at least for male urethral samples, thus increasing sensitivity of the Chlamydiazyme EIA.

scholarly journals Diagnosis and Treatment of Chronic Infectious Processes in Ophthalmology: Real Clinical Practice

2020 ◽  
Vol 17 (4) ◽  
pp. 789-795
Author(s):  
M. A. Kovalevskaya ◽  
O. V. Donkareva ◽  
O. A. Pererva
Keyword(s):  
Chlamydial Infection ◽  
Inflammatory Diseases ◽  
Family Members ◽  
Diagnosis And Treatment ◽  
Gram Negative Bacteria ◽  
Diagnostic Laboratory ◽  
Gram Negative ◽  
Ureaplasma Parvum ◽  
Causative Agents

Long-term conjunctival infections are challenging for the outpatient ophthalmologist. This is due to significant changes in microflora towards resistant gram-negative bacteria. Long-term conjunctival infections are challenging for the outpatient ophthalmologist. This is due to a significant change in microflora towards resistant gram-negative bacteria. The above studies are based on microbial associations, which are the causes of inflammatory processes, conjunctiva and cornea.Purpose: to increase the effectiveness of the diagnosis and treatment of chronic specific inflammatory diseases of the organs of vision.Patients and methods. The study was conducted in patients with chlamydial infection (n = 589) and included chronic conjunctival infections lasting more than 4 weeks, follow-up of patients with partners, family members for 3 or more years. Results. The study was carried out in patients with chlamydial infection (n = 589) and with chronic infectious diseases that lasted more than 4 weeks, following patients and family members for 3 or more years. During this period, we performed more than 3 studies for each patient — for diagnostic laboratory studies and 2 consecutive controls 1 and 2 months after treatment, mixed infection was detected in 256 people (10 %), the proportion of women was 20–30 years is 67 %, men — 51 %. In 27 % of cases, communities of Ch. trachomatis and Ureaplasma parvum as leading causative agents of the eye infections.Conclusions. Chlamydia is most often found together with Ureaplasma parvum (27 % of cases among mixed infections). Treatment of various forms of chlаmidia infection is carried out with the help of “Floxal” (0.3 % ofloxacin — drops and ointment). 

scholarly journals Mutation and Suppressor Analysis of the Essential Lipopolysaccharide Transport Protein LptA Reveals Strategies To Overcome Severe Outer Membrane Permeability Defects in Escherichia coli

2017 ◽  
Vol 200 (2) ◽  
Author(s):  
Federica A. Falchi ◽  
Elisa A. Maccagni ◽  
Simone Puccio ◽  
Clelia Peano ◽  
Cristina De Castro ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Lipid A ◽  
Antibiotic Sensitivity ◽  
Major Constituent ◽  
Permeability Barrier ◽  
Gram Negative Bacteria ◽  
Inner Membrane ◽  
Gram Negative ◽  
Outer Leaflet ◽  
Increased Sensitivity

ABSTRACTIn Gram-negative bacteria, lipopolysaccharide (LPS) contributes to the robust permeability barrier of the outer membrane (OM), preventing the entry of toxic molecules, such as detergents and antibiotics. LPS is transported from the inner membrane (IM) to the OM by the Lpt multiprotein machinery. Defects in LPS transport compromise LPS assembly at the OM and result in increased antibiotic sensitivity. LptA is a key component of the Lpt machine that interacts with the IM protein LptC and chaperones LPS through the periplasm. We report here the construction oflptA41, a quadruple mutant in four conserved amino acids potentially involved in LPS or LptC binding. Although viable, the mutant displays increased sensitivity to several antibiotics (bacitracin, rifampin, and novobiocin) and the detergent SDS, suggesting thatlptA41affects LPS transport. Indeed,lptA41is defective in Lpt complex assembly, and its lipid A carries modifications diagnostic of LPS transport defects. We also selected and characterized two phenotypic bacitracin-resistant suppressors oflptA41. One mutant, in which only bacitracin sensitivity is suppressed, harbors a small in-frame deletion inmlaA, which codes for an OM lipoprotein involved in maintaining OM asymmetry by reducing accumulation of phospholipids in the outer leaflet. The other mutant, in which bacitracin, rifampin, and SDS sensitivity is suppressed, harbors an additional amino acid substitution in LptA41 and a nonsense mutation inopgH, encoding a glycosyltransferase involved in periplasmic membrane-derived oligosaccharide synthesis. Characterization of the suppressor mutants highlights different strategies adopted by the cell to overcome OM defects caused by impaired LPS transport.IMPORTANCELipopolysaccharide (LPS) is the major constituent of the outer membrane (OM) of most Gram-negative bacteria, forming a barrier against antibiotics. LPS is synthesized at the inner membrane (IM), transported across the periplasm, and assembled at the OM by the multiprotein Lpt complex. LptA is the periplasmic component of the Lpt complex, which bridges IM and OM and ferries LPS across the periplasm. How the cell coordinates the processes involved in OM biogenesis is not completely understood. We generated a mutant partially defective inlptAthat exhibited increased sensitivity to antibiotics and selected for suppressors of the mutant. The analysis of two independent suppressors revealed different strategies adopted by the cell to overcome defects in LPS biogenesis.

Activité antimicrobienne d'antioxydants phénoliques

1978 ◽  
Vol 24 (11) ◽  
pp. 1306-1320 ◽  
Author(s):  
Pierre Turcotte ◽  
Samir A. Saheb
Keyword(s):  
Culture Media ◽  
Osmotic Shock ◽  
Bacterial Species ◽  
Butylated Hydroxytoluene ◽  
In Vitro Assays ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
The Family ◽  
Increased Sensitivity

The antimicrobial activity of three antioxydants, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA) and ethoxyquin (ETO) was studied. In vitro assays showed that when these antioxydants are added to the culture media at concentrations lower or equal to that used in nutrition, they inhibit or decrease the growth of certain microorganisms. BHT showed the most marked effect, affecting Gram-positive bacteria at a higher degree than the Gram-negative bacteria belonging to the family Enterobacteriaceae. Inactivation study of different bacterial species by BHT revealed differences in sensitivity among a single genus and between strains of the same species. The association of ETO with BHT results in an increase of the inhibitory activity. The increased sensitivity to BHT resulting from the osmotic shock of Escherichia coli cells suggests that the resistance to BHT of the Gram-negative bacteria belonging to the family Enterobacteriaceae might be due in part to the structure of their cell wall.

Prevalence of Urogenital Chlamydia Trachomatis Infection in El Salvador I. Infection during Pregnancy and Perinatal Transmission

1992 ◽  
Vol 3 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Ana Berta Cañas Posada ◽  
Jon Jonasson ◽  
Leonor de Linares ◽  
Solgun Bygdeman
Keyword(s):  
Chlamydia Trachomatis ◽  
Pregnant Women ◽  
El Salvador ◽  
Chlamydial Infection ◽  
Perinatal Transmission ◽  
Direct Immunofluorescence ◽  
Chlamydia Trachomatis Infection ◽  
San Salvador ◽  
Age Range ◽  
Chlamydial Antigen

One-hundred and twenty-nine pregnant women in labour (age range 15–46 years; median age 23) and 42 infants born to chlamydia-positive mothers (age range 5–15 days; median age 10) were investigated to estimate the prevalence and incidence, respectively, of Chlamydia trachomatis infection in San Salvador, El Salvador. Urethral and cervical samples were obtained from all women and conjunctival specimens were taken from both eyes of each child. The chlamydial antigen was detected with the commercial Pharmacia Chlamydia EIA kit. Direct immunofluorescence (DFA) (Syva MicroTrak) was used for confirmation. In the newborns both EIA and DFA tests on direct preparations from ocular smears were performed on all the samples. The prevalence of chlamydial infection in pregnant women was 44% (57/129). The incidence of chlamydial infection in neonates was 64% (27/42), and the majority of the infected children (56%) had conjunctivitis. Referring to individuals rather than specimens the sensitivity of EIA tests on conjunctival samples from the infants was low (37%) as compared with 91% on urethral and cervical specimens from the pregnant women.

Success and Challenges Associated with Large Scale Collaborative Surveillance for Carbapenemase Genes in Gram Negative Bacteria

2021 ◽  
Author(s):  
Sanchita Das ◽  
Karen Bush
Keyword(s):  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Large Scale ◽  
Resistance Mechanisms ◽  
Gram Negative Bacteria ◽  
Routine Laboratory ◽  
Significant Morbidity ◽  
Gram Negative ◽  
Surveillance Studies ◽  
The One

The emergence and spread of antimicrobial resistance, especially in Gram negative bacteria has led to significant morbidity and increased cost of healthcare. Large surveillance studies such as the one performed by the Antibiotic Resistance Laboratory Network are immensely valuable in understanding the scope of resistance mechanisms especially among carbapenemase producing Gram negative bacteria. However, the routine laboratory detection of carbapenemases in these bacteria remain challenging and require further optimization.

Bacterial-Mucosal Cell Junctional Complexes

1974 ◽  
Vol 32 ◽  
pp. 144-145
Author(s):  
Roger C. Wagner
Keyword(s):  
Intestinal Wall ◽  
Rat Colon ◽  
Mucosal Cell ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Mucosal Cells ◽  
Mucosal Lining ◽  
Degenerative Alterations ◽  
Junctional Complexes ◽  
Intestinal Mucosal Cells

Bacteria exhibit the ability to adhere to the apical surfaces of intestinal mucosal cells. These attachments either precede invasion of the intestinal wall by the bacteria with accompanying inflammation and degeneration of the mucosa or represent permanent anchoring sites where the bacteria never totally penetrate the mucosal cells.Endemic gram negative bacteria were found attached to the surface of mucosal cells lining the walls of crypts in the rat colon. The bacteria did not intrude deeper than 0.5 urn into the mucosal cells and no degenerative alterations were detectable in the mucosal lining.

Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

1992 ◽  
Vol 50 (1) ◽  
pp. 686-687
Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara
Keyword(s):  
Chronic Arthritis ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Infectious Arthritis ◽  
Bacterial Arthritis ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

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.

Application of EM to differentiate herpes virus from pox virus in genital specimens

1994 ◽  
Vol 52 ◽  
pp. 262-263
Author(s):  
K. Rekrut ◽  
K. Schleuter
Keyword(s):  
Tissue Culture ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Fresh Tissue ◽  
Culture Cells ◽  
Viral Transport ◽  
Carbon Coated ◽  
Immuno Assay ◽  
Simplex Virus ◽  
Enzyme Immuno Assay

Confirmation of herpes simplex virus (HSV) from genital lesions of obstetrical (OB) patients may affect both the management of the delivery and of the neonate.(l,2) During 1992 and 1993, 4,450 genital specimens from OB patients were submitted in viral transport media for herpes culture. The specimens were inoculated into MRC-5, Vero, and A-549 tissue culture tubes, incubated, and examined daily for 7 days for cytopathic effect (CPE). The original specimens were frozen at −70° C until final reports were issued. Culture tubes with CPE were tested by the Dupont Herpchek enzyme immuno assay (EIA) to confirm the presence of herpes simplex virus (HSV). (3,4) 170 OB patient specimens were positive by culture and confirmed by EIA.There were also 63 cultures exhibiting CPE ressembling HSV which were negative by EIA testing, which failed to pass in fresh tissue culture cells or progress to more enhanced CPE in culture. These original specimens were screened by electron microscopy after direct ultracentrifugation employing the Beckman airfuge with the EM 90 rotor on to formvar carbon-coated 300 mesh copper grids and negatively stained with 2% PTA.

Ultrastructure of periplasmic bodies in gram-negative bacteria

1990 ◽  
Vol 48 (3) ◽  
pp. 640-641
Author(s):  
Xie Nianming ◽  
Ding Shaoqing ◽  
Wang Luping ◽  
Yuan Zenglin ◽  
Zhan Guolai ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Campylobacter Jejuni ◽  
Proteus Mirabilis ◽  
Shigella Flexneri ◽  
Morphological Description ◽  
Gram Negative Bacteria ◽  
Periplasmic Space ◽  
Clostridium Tetani ◽  
Gram Negative ◽  
Brucella Canis

Perhaps the data about periplasmic enzymes are obtained through biochemical methods but lack of morphological description. We have proved the existence of periplasmic bodies by electron microscope and described their ultrastructures. We hope this report may draw the attention of biochemists and mrophologists to collaborate on researches in periplasmic enzymes or periplasmic bodies with each other.One or more independent bodies may be seen in the periplasmic space between outer and inner membranes of Gram-negative bacteria, which we called periplasmic bodies. The periplasmic bodies have been found in seven species of bacteria at least, including the Pseudomonas aeroginosa. Shigella flexneri, Echerichia coli. Yersinia pestis, Campylobacter jejuni, Proteus mirabilis, Clostridium tetani. Vibrio cholerae and Brucella canis.

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