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1.
Lett Appl Microbiol ; 74(5): 729-740, 2022 May.
Article in English | MEDLINE | ID: mdl-35076956

ABSTRACT

This study aimed to investigate the molecular mechanisms of carbapenem and colistin resistance in K. pneumoniae and E. coli isolates obtained from hospitalized patients in Carthagene International Hospital of Tunis. A total of 25 K. pneumoniae and 2 E. coli clinical isolates with reduced susceptibility to carbapenems were recovered. Susceptibility testing and phenotypic screening tests were carried out. ESBL, AmpC, carbapenemase and other antibiotic resistance genes were sought by PCR-sequencing. The presence of plasmid-mediated colistin resistance genes (mcr-1-8) was examined by PCR and the nucleotide sequence of the mgrB gene was determined. The analysis of plasmid content was performed by PCR-Based Replicon Typing (PBRT). The clonality of isolates was assessed by PFGE and multilocus sequence typing (MLST). All of the isolates produced carbapenemase activity. They showed a great variation in the distribution of ESBL, AmpC, carbapenemase and other plasmid-mediated resistance determinants. K. pneumoniae isolates carried blaNDM-1 (n = 11), blaOXA-48 (n = 11), blaNDM-1 + blaOXA-48 (n = 1), blaNDM-1 + blaVIM-1 (n = 1), blaOXA-204 (n = 1), along with blaCTX-M , blaOXA , blaTEM , blaCMY , blaDHA and blaSHV genes variants on conjugative plasmid of IncL/M, IncR, IncFIIK , IncFIB, and IncHI1 types. Three sequence types ST101, ST307 and ST15 were identified. The mgrB alteration g109a (G37S) was detected in a single colistin-resistant, NDM-1 and OXA-48-coproducing K. pneumoniae isolate. The two E. coli isolates belonged to ST95, co-produced NDM-1 and CTX-M-15, and harboured plasmid of IncFII and IncFIB types. To our knowledge, this is the first report in Tunisia of NDM-1, OXA-48, and CTX-M-15 coexistence in colistin-resistant K. pneumoniae ST15.


Subject(s)
Escherichia coli Proteins , Klebsiella Infections , Pneumonia , Anti-Bacterial Agents/pharmacology , Bacterial Proteins , Carbapenems , Colistin/pharmacology , Escherichia coli/genetics , Escherichia coli Proteins/genetics , Humans , Klebsiella pneumoniae/genetics , Microbial Sensitivity Tests , Multilocus Sequence Typing , Plasmids/genetics , Tunisia , beta-Lactamases/genetics
2.
Rev Epidemiol Sante Publique ; 69(3): 116-126, 2021 Jun.
Article in French | MEDLINE | ID: mdl-33966926

ABSTRACT

OBJECTIVE: To objectively assess the quality of "crisis communication" media, during the COVID-19 pandemic, in the three Greater Maghreb countries (Tunisia, Algeria, Morocco). METHODS: A compliance audit for press releases and epidemiological bulletins was analyzed against a quality benchmark, which had been specifically designed by the authors. This framework, made up of five dimensions and 50 items, graded (0/1), was applied by two researchers in preventive medicine. Multiplying the scores by a coefficient of two resulted in a partial score of 20 points for each dimension and a total score of 100 points for the checklist taken as a whole. The quality of the communication media was considered to be good when exceeding the thresholds of 15/20 for the different dimensions and 75/100 for the entire grid. RESULTS: A total of 141 information media were included in this audit (Tunisia: 60; Algeria: 60; Morocco: 21). The overall median quality score for these media was only 56/100 (IIQ: [46-58]), without major variability between countries. The most appreciated dimension was "maintaining the confidence of the population", with an overall median score of 14/20 (12/20 for epidemiological bulletins and 16/20 for press releases). The most poorly rated dimension was "strengthening community participation", with a median score of only 4/20 (6/20 for epidemiological bulletins and 4/20 for press releases). CONCLUSION: The quality of the Maghreb crisis communication media during COVID-19 was insufficient in most of its dimensions and items, particularly from a psychosocial standpoint. Reinforcement of the capacities of communication officers to develop information material and supports during health crises is indispensable and should be considered as an urgent matter.


Subject(s)
COVID-19/epidemiology , Communications Media/standards , Algeria/epidemiology , Humans , Morocco/epidemiology , Tunisia/epidemiology
3.
Semin Ophthalmol ; 30(2): 150-3, 2015 Mar.
Article in English | MEDLINE | ID: mdl-24117413

ABSTRACT

PURPOSE: To describe the use of a Boston type I keratoprosthesis as a secondary penetrating procedure to treat gelatinous drop-like corneal dystrophy (GDLD), with presentation of pathologic findings, genetic analysis, and discussion of other surgical options. METHODS: A 43-year-old woman with GDLD in both eyes, best corrected visual acuity (BCVA) of counting fingers in both eyes, and recurrent corneal opacification following two penetrating keratoplasties presented for visual rehabilitation. A Boston type I keratoprosthesis was implanted in her left eye after extracapsular clear lens extraction. RESULTS: The surgery was uneventful and one month after surgery, best corrected vision improved to 20/30, which has been maintained for a period of more than nine months. At the 12-month visit, her vision was noted to be diminished to 20/200 due to a retroprosthetic membrane and improved to 20/25 two weeks after a Yag capsulotomy. Histopathologic examination of the corneal specimen disclosed predominantly subepithelial amyloid deposition. Genetic analysis is presented. CONCLUSIONS: GDLD is a rare disorder of primary corneal amyloidosis. Recurrence of this condition following surgery is very common. Boston type I keratoprosthesis as a secondary procedure can be successful in restoring vision in affected patients.


Subject(s)
Amyloidosis, Familial/surgery , Bioartificial Organs , Corneal Dystrophies, Hereditary/surgery , Graft Rejection/surgery , Prosthesis Implantation , Adult , Amyloidosis, Familial/genetics , Amyloidosis, Familial/physiopathology , Antigens, Neoplasm/genetics , Cell Adhesion Molecules/genetics , Consanguinity , Corneal Dystrophies, Hereditary/genetics , Corneal Dystrophies, Hereditary/physiopathology , Corneal Transplantation , Female , Graft Rejection/diagnosis , Humans , Lens, Crystalline/surgery , Mutation , Prostheses and Implants , Visual Acuity/physiology
4.
Br J Ophthalmol ; 87(11): 1312-6, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14609821

ABSTRACT

AIMS: To evaluate umbilical cord serum therapy as a means of promoting the healing of persistent corneal epithelial defects. METHODS: Umbilical cord serum or autologous serum drops were used to promote the healing of persistent epithelial defects. The study design was a prospective randomised controlled clinical trial. 60 eyes of 59 patients were divided into two groups, 31 in the cord serum group and 29 in the autologous serum control group. Epithelial defects measuring at least 2 mm in linear dimension resistant to conventional medical management were included. Serial measurements of the size of the epithelial defects-namely, two maximum linear dimensions perpendicular to each other, and the area and perimeter was done at start of therapy and follow up days 3, 7, 14, 21. Rate of healing of the epithelial defects were measured as percentage decrease from the baseline parameter at each subsequent follow up. The data were analysed by the non-parametric Wilcoxon rank sum test using STATA 7.0. RESULTS: The median percentage decrease in the size of the epithelial defect was significantly greater in the cord serum group at days 7, 14 and 21 (p<0.05) when measured in terms of the area and perimeter. A greater number of patients showed complete re-epithelialisation with umbilical cord serum (n = 18) than with autologous serum (n = 11) (Pearson chi = 0.19). None of the patients reported any side effects or discomfort with either treatment. CONCLUSIONS: Umbilical cord serum leads to faster healing of the persistent corneal epithelial defects refractory to all medical management compared to autologous serum.


Subject(s)
Epithelium, Corneal/injuries , Fetal Blood , Serum , Wound Healing , Adult , Double-Blind Method , Female , Follow-Up Studies , Humans , Male , Middle Aged , Pregnancy , Prospective Studies , Statistics, Nonparametric , Transplantation, Autologous
5.
Surv Ophthalmol ; 46(2): 95-116, 2001.
Article in English | MEDLINE | ID: mdl-11578645

ABSTRACT

Laser in situ keratomileusis (LASIK) is a rapidly evolving ophthalmic surgical procedure. Several anatomic and refractive complications have been identified. Anatomic complications include corneal flap abnormalities, epithelial ingrowth, and corneal ectasia. Refractive complications include unexpected refractive outcomes, irregular astigmatism, decentration, visual aberrations, and loss of vision. Infectious keratitis, dry eyes, and diffuse lamellar keratitis may also occur following LASIK. By examining the etiology, management, and prevention of these complications, the refractive surgeon may be able to improve visual outcomes and prevent vision-threatening problems. Reporting outcomes and mishaps of LASIK surgery will help refine our approach to the management of emerging complications.


Subject(s)
Corneal Diseases/etiology , Corneal Diseases/prevention & control , Keratomileusis, Laser In Situ/adverse effects , Cornea/surgery , Corneal Diseases/diagnosis , Corneal Topography , Humans , Vision Disorders/diagnosis , Vision Disorders/etiology , Vision Disorders/prevention & control
6.
Ophthalmology ; 107(12): 2136-9, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11097584

ABSTRACT

PURPOSE: To report the management and outcome of late-onset traumatic dislocation of laser in situ keratomileusis (LASIK) flaps. DESIGN: Retrospective, observational case series. PARTICIPANTS: Four patients with late-onset LASIK flap dislocation occurring after mechanical trauma at various intervals (10 days-2 months) after the procedure. INTERVENTION: In all cases of postoperative traumatic LASIK flap dislocation, the flap was refloated with scraping and irrigation of the underlying stromal bed within 12 hours of the injury. A bandage contact lens was placed, and a regimen including topical antibiotics and corticosteroids was instituted in all cases. MAIN OUTCOME MEASURES: Best spectacle-corrected visual acuity and complications associated with the surgery were monitored. RESULTS: Postoperative follow-up ranged from 4 to 21 months. Nonprogressive epithelial ingrowth was noted in one patient and diffuse lamellar keratitis developed in another patient. All patients recovered pretrauma spectacle-corrected visual acuity. CONCLUSIONS: Corneal LASIK flaps are prone to mechanical dislocation as late as 2 months after the procedure. Appropriate management results in recovery of optimal visual outcomes.


Subject(s)
Corneal Injuries , Eye Injuries/etiology , Joint Dislocations/etiology , Keratomileusis, Laser In Situ , Surgical Flaps , Surgical Wound Dehiscence/etiology , Wounds, Nonpenetrating/etiology , Adult , Cornea/pathology , Cornea/surgery , Eye Injuries/pathology , Eye Injuries/surgery , Female , Humans , Joint Dislocations/pathology , Joint Dislocations/surgery , Male , Middle Aged , Myopia/surgery , Retrospective Studies , Surgical Wound Dehiscence/pathology , Surgical Wound Dehiscence/surgery , Visual Acuity , Wounds, Nonpenetrating/pathology , Wounds, Nonpenetrating/surgery
7.
Invest Ophthalmol Vis Sci ; 41(11): 3335-40, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11006222

ABSTRACT

PURPOSE: To determine the efficacy of photochemical keratodesmos (PKD) for closing surgical incisions in the cornea of enucleated rabbit eyes compared with that achieved using sutures and self-sealing incisions. METHODS: A 3.5-mm incision, at an angle parallel to the iris, was made in the cornea of enucleated New Zealand White rabbit eyes. The intraocular pressure required to cause leakage (IOP(L)) from the untreated incision was then recorded. Photochemical keratodesmos treatment was then performed by application of a dye, Rose Bengal (RB), in saline solution to the surfaces of the incision wound, followed by laser irradiation at 514 nm from an argon ion laser. Immediately after treatment, the IOP(L) was measured. Both dose and laser irradiance dependencies were studied in five or more eyes for each condition and appropriate control eyes. The IOP(L)s were compared with those obtained using conventional interrupted 10-0 nylon sutures. Other dyes were tested in a similar fashion. RESULTS: The IOP(L) of 300 mm Hg was obtained using a fluence of 1270 J/cm(2) with an irradiance of 1.27 W/cm(2) (laser exposure time, 16 minutes 40 seconds). No sealing was observed using dye or light alone where control pressures of approximately 30 mm Hg were found. At higher dose (1524 J/cm(2)) and irradiance (3.82 W/cm(2); 6 minutes 35 seconds), PKD was less effective, which may be attributable to thermal effects. PKD produced IOP(L)s similar to those in closure by sutures. Other dyes such as riboflavin-5-phosphate and N:-hydroxy-pyridine thione also produced efficient bonding after PKD. Nonphotochemically active dyes did not produce significant increases in the IOP(L) at which leakage occurred. CONCLUSIONS: The increase in IOP(L) after PKD treatment, comparable with that with sutures, in enucleated rabbit eyes demonstrates the feasibility of this technique ex vivo.


Subject(s)
Cornea/surgery , Photochemotherapy , Photosensitizing Agents/therapeutic use , Surgical Wound Dehiscence/prevention & control , Wound Healing/drug effects , Animals , Cornea/physiopathology , Flavin Mononucleotide/therapeutic use , Fluorescein/therapeutic use , Intraocular Pressure/physiology , Lasers , Methylene Blue/therapeutic use , Pyridines/therapeutic use , Rabbits , Rose Bengal/therapeutic use , Surgical Wound Dehiscence/physiopathology , Suture Techniques , Thiones
8.
Graefes Arch Clin Exp Ophthalmol ; 238(5): 459-62, 2000 May.
Article in English | MEDLINE | ID: mdl-10901479

ABSTRACT

PURPOSE: To compare the antibacterial effect of povidone-iodine (PI) with that of ofloxacin in an experimental model of bacterial keratitis. METHODS: Staphyloccocal keratitis was induced in 21 eyes of Dutch Belted rabbits by intrastromal inoculation of approximately 280 organisms of Staphylococcus aureus. Six hours later, the animals were divided in four groups treated topically with saline 0.9%, Betadine 10%, Betadine 0.5% or Ofloxacin 0.3% (2 gtt every 30 min for 8 h). The central 8-mm cornea was excised, washed and homogenized. Colony counts were performed on serial 10-fold dilutions plated on blood and brain infusion agar and incubated overnight. RESULTS: Colony-forming units per cornea were 7.4x10(7) for the saline group compared to 8.2x10(7) for PI 10% (P>0.5), 4.3x10(7) for PI 0.5% (P<0.01) and no organisms for ofloxacin 0.3%. CONCLUSIONS: Betadine 0.5% demonstrates a statistically significant bactericidal effect compared with untreated staphyloccocal keratitis in our experimental model. Ofloxacin has superior antibacterial effect under the conditions studied. Further improvements in the povidone-iodine formulation are warranted prior to consideration for human keratitis.


Subject(s)
Anti-Infective Agents/administration & dosage , Eye Infections, Bacterial/drug therapy , Iodophors/administration & dosage , Keratitis/drug therapy , Ofloxacin/administration & dosage , Povidone-Iodine/administration & dosage , Staphylococcal Infections/drug therapy , Animals , Colony Count, Microbial , Cornea/microbiology , Disease Models, Animal , Eye Infections, Bacterial/microbiology , Eye Infections, Bacterial/pathology , Keratitis/microbiology , Keratitis/pathology , Male , Ophthalmic Solutions , Rabbits , Staphylococcal Infections/microbiology , Staphylococcal Infections/pathology , Staphylococcus aureus/drug effects , Staphylococcus aureus/growth & development , Staphylococcus aureus/isolation & purification
10.
Ophthalmology ; 106(7): 1262-7, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10406603

ABSTRACT

OBJECTIVE: To describe the potential acuity pinhole (PAP) test and compare its accuracy to the potential acuity meter (PAM) in predicting visual outcome after cataract surgery. STUDY DESIGN: Prospective case series. PARTICIPANTS: A total of 56 preoperative patients with cataracts participated. MAIN OUTCOME MEASURES: Accuracy of predicting postoperative distance visual acuity was measured. METHODS: Lines of inaccuracy were calculated by subtracting actual postoperative best-corrected distance visual acuity (BCVA) from predicted values. Variables analyzed were method of prediction, preoperative BCVA, and preoperative spherical equivalent. RESULTS: The PAP test predicted visual outcomes within 2 lines in 100%, 100%, and 56% of eyes with preoperative BCVA of 20/50 and better (group 1), 20/60 to 20/100 (group II), and 20/200 and worse (group III), respectively. The PAM predictions within 2 lines for the same groups were 42%, 47%, and 0%, respectively. Mean lines of inaccuracy of PAP predictions were 0.83, 1.11, and 3.50 lines for groups I, II, and III, respectively. Mean lines of inaccuracy for PAM predictions were 2.50, 2.68, and 6.22 lines for the same groups. Differences in lines of prediction between PAM and PAP were 1.67 (P = 0.004), 1.58 (P = 0.0002), and 2.72 lines (P = 0.0001) for groups I, II, and III, respectively. There was no statistically significant correlation between PAP predictions and preoperative myopic spherical equivalent. CONCLUSIONS: The PAP test is a simple, inexpensive, and relatively reliable method to estimate visual outcome after uncomplicated cataract surgery in eyes with no coexisting disease. It is less accurate in patients with preoperative BCVA worse than 20/200. It appears to be more predictive than PAM.


Subject(s)
Cataract/physiopathology , Vision Tests/methods , Visual Acuity , Adult , Aged , Aged, 80 and over , Cataract Extraction , Female , Humans , Lens Implantation, Intraocular , Male , Middle Aged , Predictive Value of Tests , Prospective Studies , Reproducibility of Results
11.
J Lipid Res ; 34(9): 1527-34, 1993 Sep.
Article in English | MEDLINE | ID: mdl-7693843

ABSTRACT

The adipocyte fatty acid-binding protein, aP2 or ALBP, is an abundant cytosolic protein postulated to function in binding and intracellular transport of long-chain fatty acids. In this report, we investigated levels of aP2 mRNA and protein and transcriptional activity of the aP2 gene in tissues from streptozotocin-diabetic rats at different time periods following the induction of diabetes. An average 75% decrease in mRNA for aP2 (relative to mRNA for beta-actin) was observed in all diabetic rats at 7 days post-STZ injection. Insulin supplementation rapidly (2 h) restored aP2 mRNA and the insulin effect was cycloheximide-sensitive. Nuclear transcription assays measured a 60% decrease in transcription of the aP2 gene in diabetic rats that was reversed by insulin administration. Levels of aP2 protein were still high, in some cases, 1 day after the decrease in mRNA levels consistent with a long half-life of the protein. Decreases in aP2 protein were rapidly reversed by insulin administration. There were no changes in aP2 protein in the absence of changes in aP2 mRNA supporting a pretranslational mechanism of regulation. The decrease in aP2 mRNA was delayed in onset when compared with the rapid decline (at day 2 of diabetes) of mRNA for the lipogenic enzyme, fatty acid synthase, and with the accelerated depletion of adipose tissue lipid. Adipose tissue weight and lipid content had decreased by more than 80% 3 days before any significant changes in aP2 expression were observed. Changes in aP2 could not be related to changes in the levels of circulating fatty acids that regulate aP2 expression in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Adipocytes/physiology , Carrier Proteins/biosynthesis , Diabetes Mellitus, Experimental/metabolism , Insulin/deficiency , Insulin/pharmacology , Neoplasm Proteins , Nerve Tissue Proteins , Animals , Blood Glucose/analysis , Carrier Proteins/genetics , Diabetes Mellitus, Experimental/genetics , Fatty Acid-Binding Protein 7 , Fatty Acid-Binding Proteins , Fatty Acids/blood , Fatty Acids/genetics , Gene Expression/genetics , Immunoblotting , Insulin/blood , Male , RNA/analysis , Rats , Rats, Sprague-Dawley , Transcription, Genetic/genetics
12.
J Lipid Res ; 33(5): 669-78, 1992 May.
Article in English | MEDLINE | ID: mdl-1619361

ABSTRACT

Studies of fatty acid (FA) esterification by adipocytes have led to conflicting views with respect to how the process is regulated by norepinephrine (NE). It remains unclear whether NE directly modulates the pathway or whether its effects are indirect and reflect its well-known action to activate lipolysis. Changes in lipolysis can complicate estimation of esterification rates by altering both medium FA and the hydrolysis of newly formed FA esters. In this report, we describe an experimental approach that determined the effect of NE on FA esterification, amidst the complications introduced by activation of lipolysis. Esterification rates were estimated from the simultaneous incorporations (0.1-60 min) of [14C]glucose and [3H]oleate into diglyceride (DG), phospholipid (PL), and triglyceride (TG). Saturation kinetics of incorporation rates, with respect to FA, and more specifically to unbound or albumin-free FA (ubFA), were determined in both basal and NE-treated cells. To obtain true estimates of ester synthesis, incorporation rates were adjusted for label loss from breakdown of labeled esters. Our findings were: 1) In basal versus NE-treated cells, [3H]oleate, on its pathway to esterification, was diluted, respectively, by 2 and 50% of measured cell FA, and the diluting FA appeared derived from lipolysis. 2) Syntheses of PL, DG, and TG, estimated from incorporation of [14C]glucose, saturated at low ubFA. The Km for TG synthesis (0.06 microM) was within the physiological range of ubFA which meant that changes in plasma FA will modulate TG synthesis. PL synthesis, on the other hand (Km less than 0.01 microM), would be largely saturated under physiological conditions. 3) NE treatment increased the molar ratio of FA to albumin in the medium an average 8-fold and ubFA about 87-fold. In addition, NE accelerated hydrolysis of labeled PL and DG. Adjusting incorporation rates for these changes indicated that NE does not directly regulate glyceride synthesis. The assays described should allow estimation of glycerolipid synthesis under various metabolic or disease states and will distinguish direct effects from those reflecting changes in FA concentration or in hydrolysis of labeled FA esters.


Subject(s)
Adipose Tissue/metabolism , Diglycerides/biosynthesis , Norepinephrine/pharmacology , Phospholipids/biosynthesis , Triglycerides/biosynthesis , Adipose Tissue/cytology , Animals , Cell Membrane/metabolism , Chromatography, Thin Layer , Esterification , Fatty Acids/metabolism , Glucose/metabolism , Hydrolysis , Oleic Acid , Oleic Acids/metabolism , Rats , Rats, Inbred Strains
13.
Am J Physiol ; 261(1 Pt 1): E76-86, 1991 Jul.
Article in English | MEDLINE | ID: mdl-1858876

ABSTRACT

Incorporation of [3H]oleate and [14C]glucose into cellular lipids was studied in the preadipose cell line BFC-1 to determine flux changes that accompany the adipose conversion process. Dilution of oleate by intracellular fatty acids (FA) was estimated from the 3H/14C incorporation ratios and from relating steady-state radioactivity in diglycerides to their measured cellular levels. The data indicated that exogenous FA mixed with less than 1% of endogenous FA on its pathway to esterification. Conversion of preadipocytes to adipocytes increased uptake of FA and glucose by approximately 3-fold and synthesis of diglycerides and triglycerides by 5- and 16-fold, respectively, with little if any increase of phospholipid synthesis. A 50% drop in 3H/14C incorporation ratio indicated a doubling of the rate at which endogenous FA mixed with the exogenous FA that had entered the cell. Adipocytes compared with preadipocytes exhibited a 50% greater cell diameter and a doubling of intracellular water volume and of protein and phospholipid levels, reflecting cellular enlargement consequent to the arrest of cell division that precedes adipose conversion. Diglyceride levels were also increased in adipocytes, however, since their turnover was fast, as indicated by rapid equilibration of diglyceride labeling; the increase reflected changes in their relative rates of synthesis and disposal. Diglyceride levels related to cell phospholipid, and other indexes of cell size remained constant. This indicated that the supply of diglycerides was tightly coupled to the synthesis of triglycerides and phospholipids, which suggested feedback regulation of diglyceride formation. The studies provide a methodological approach to measurement and interpretation of rates of lipid deposition in cultured cells.


Subject(s)
Adipose Tissue/metabolism , Neoplasm Proteins , Nerve Tissue Proteins , Oleic Acids/metabolism , Adipose Tissue/cytology , Animals , Carrier Proteins/metabolism , Cell Differentiation , Cell Division , Cell Line , Cytosol/metabolism , Fatty Acid-Binding Protein 7 , Fatty Acid-Binding Proteins , Glycerol/metabolism , Kinetics , Lipolysis , Mice , Oleic Acid , Phospholipids/metabolism , Triglycerides/metabolism
15.
J Immunol Methods ; 119(2): 189-96, 1989 May 12.
Article in English | MEDLINE | ID: mdl-2470824

ABSTRACT

We evaluated a method for the assessment of the phagocytic and bactericidal activity of human peripheral neutrophils against Staphylococcus aureus Cowan I, which is a modified version of the acridine orange staining technique originally described by Smith and Rommel (1977). The modification consisted of the use of free leukocyte suspensions rather than coverglass adhered leukocytes in order to avoid two main problems: the inefficient neutrophil adherence to glass that can be observed in specimens from patients with certain functional phagocyte defects, and the risk of selecting among neutrophils. An additional advantage of the modified procedure is that it permits a uniform bacteria: phagocyte ratio in different cell samples. The method was tested on 25 healthy adults and on four children with functional phagocytic defects (chronic granulomatous disease of infancy, Chediak-Higashi syndrome, and Rothmund-Thomson syndrome associated to persistent neutropenia and low chemotactic response). The neutrophils of all four patients showed a low bactericidal activity, with percent values of intracellular killed bacteria below the mean +/- 2 SD range observed in the healthy population at all incubation times tested (5, 15 and 30 min). A significant reduction in phagocytosis index and in % killed unopsonized S. aureus was observed in relation to bacteria treated with a pool of normal human serum. These results demonstrate the high sensitivity of the method, which could be used to determine intrinsic and extrinsic functional alterations in human neutrophils.


Subject(s)
Acridine Orange , Blood Bactericidal Activity , Neutrophils/immunology , Phagocyte Bactericidal Dysfunction/immunology , Staining and Labeling , Adult , Child , Child, Preschool , Female , Humans , Infant , Kinetics , Male , Neutrophils/microbiology , Phagocyte Bactericidal Dysfunction/blood , Phagocyte Bactericidal Dysfunction/microbiology , Phagocytosis , Sex Factors , Staining and Labeling/methods , Staphylococcus aureus/immunology
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