Diane Dryja

A superantigen hypothesis for the pathogenesis of chronic hyperplastic sinusitis with massive nasal polyposis

Background The pathogenesis of chronic hyperplastic sinusitis with massive nasal polyposis is still an enigma; however, the molecular biology of this disease is beginning to become unraveled and the proinflammatory cytokines and the message and the product of these cytokines have all been identified in nasal polyps. However, the initial trigger that causes inflammation of the lateral wall of the nose to up-regulate lymphocytes and eosinophils is still unknown. Methods Thirteen patients with massive polyposis were studied. The mucus of the nasal cavities surrounding the nasal polyps was studied for both bacterial and fungal species. The lymphocytes of the nasal polyps were extracted and evaluated for the T-cell receptor, particularly, the variable β region of this receptor. Enterotoxins (superantigens) of the bacteria were studied. Finally, the histopathology of nasal polyps was studied. Results Fifty-five percent of the patients had toxin-producing Staphylococcus aureus in the nasal mucus adjacent to the polyps. Three different enterotoxins were isolated, including Staphylococcus enterotoxin A, Staphylococcus enterotoxin B, and toxic shock syndrome toxin 1. The variable B specificity for these superantigens was identified also in the polyp lymphocyte T-cell receptor. Conclusion A superantigen hypothesis for massive polyposis is suggested because the most common bacterial species found in the nasal mucus is Staphylococcus aureus. These bacteria produce enterotoxins in all of the cases studied and the corresponding variable β region of the T-cell receptor also was up-regulated in the polyp lymphocytes in cases studied thus far. These data taken together suggest that the initial injury to the lateral wall of the nose may be the result of toxin-producing Staphylococci. Superantigens (enterotoxins) may up-regulate lymphocytes to produce cytokines that are responsible for the massive up-regulation of lymphocytes, eosinophils, and macrophages, the three most common inflammatory cells found in massive nasal polyposis.

Immune Responses in Rhesus Rotavirus-Challenged Balb/c Mice Treated with Bifidobacteria and Prebiotic Supplements

Bifidobacterium species (B. bifidum and B. infantis), with or without prebiotic compounds (arabino-galactan, short-chain fructo-oligosaccharide, iso-malto-dextrins), were orally fed to Balb/c pups (n = 192) to evaluate their potential synergistic effects on modulating the course of rhesus rotavirus (RRV) infection, as well as their ability to mediate the associated mucosal and humoral immune responses. Rotavirus-specific IgA and IgG in serum, rotavirus antigen, and specific IgA in feces were measured by ELISA. Mucosal total IgA and IgG levels were determined in Peyers patches by flow cytometry. Significantly delayed onset (p = 0.001) and early resolution (p < 0.001) of diarrhea were observed in bifidobacteria-treated, RRV-infected mice compared with RRV-infected control mice. Supplementation with prebiotic compounds did not shorten the clinical diarrhea course more than that observed with bifidobacteria treatment alone. Rotavirus-specific IgA in feces was 16-fold elevated on d 5 postinfection in bifidobacteria-treated, RRV-infected mice compared with the RRV-infected alone group. In addition, the level of rotavirus-specific IgA in serum was four-fold higher in bifidobacteria-treated, RRV-infected litters versus mice challenged with RRV alone on 28 and 42 d postinfection. No enhancement of the immune response was found in RRV-infected mice that were treated with both bifidobacteria and prebiotic compounds over those treated with bifidobacteria only. The findings suggest that bifidobacteria may act as an adjuvant by modulating early mucosal and strong humoral rotavirus-specific immune responses, and mitigate severity of rotavirus-induced diarrhea.

Effectiveness of Bifidobacterium bifidum in Mediating the Clinical Course of Murine Rotavirus Diarrhea

ABSTRACT: Human Bifidobacterium sp strain bifidum (B. bifidum) was administered to BALB/c lactating mice (n = 58) and their litters (n = 327 pups) to evaluate the ingested strains adherent properties and ability to inhibit murine rotavirus (MRV) infection. ELISA and anaerobic bacteriologic techniques were used to measure MRV shedding and colonization of Bifidobacterium in the small intestine. At 13–16 d gestation, pregnant dams (and their expected litters) were randomly assigned to one of four experimental groups: 7) normal controls; 2) B. bifidum- treated only; 3) MRV-infected only; and 4) B. bifidum- treated + MRV-infected dams and litters. During the acute phase of diarrhea, 80% of small-intestine cultures in B. bifidum-treated litters were positive for the ingested B. bifidum strain compared with 24% of fecal cultures. Examination of tissue cross sections under electron microscopy revealed the ingested B. bifidum strain survived passage through the upper gastrointestinal tract and adhered to the small-intestine epithelium. After the administration of the high dose of virus, diarrhea developed in all pups, but onset was significantly delayed in B. bifidum-treated + MRV-infected litters compared with litters infected with MRV only (p < 0.02). B. bifidum-treated + MRV-infected pups demonstrated a significant reduction in MRV shedding compared with litters challenged with MRV only at d 2 to 10 after inoculation (p < 0.009). More direct studies are needed to assess mechanisms by which this anaerobe can alter the course of MRV infection at the level of gut epithelium.

Concordance of Bacterial Cultures with Endotoxin and Interleukin-6 in Necrotizing Enterocolitis

Concordance between gram-negative enteric andother toxin-producing bacteria in blood and stoolculture, endotoxin (lipopolysaccharide), andinterleukin-6 (IL-6) was measured in 60 preterm infants(600-1600 g) as a clinical index in neonatal necrotizingenterocolitis (NEC). E. coli, Klebsiella, Enterobacter,and Clostridium spp., identified by routinebacteriology, were each strongly associated withelevated concentrations of endotoxin (P < 0.01) instool filtrates, with Clostridium spp. most stronglyassociated with NEC disease. Stool filtrate endotoxin(EU/g) measured by a Limulus amebocyte lysate assay was age dependent. Samples from stage I NEC (61%)and infants with advanced disease (67%) had notablyelevated levels of stool endotoxin (>10 ln EU/g)compared to NEC-negative (47%) samples tested. Plasmaand stool IL-6 generally tested at the low,nonmeasurable limit of the ELISA for NEC-negative (88%)and stage I NEC (93%), although a small proportion ofsamples (25%) from infants with stage II or III NEC had elevated stool concentrations of IL-6. Weconclude that identification of toxin-producingorganisms and endotoxin elevations in stool filtratesare more useful than circulating levels of endotoxin in plasma in predicting mucosally limited diseasein the gastrointestinal tract. The prognostic value ofmonitoring stool endotoxin in infants with overgrowth ofgram-negative bacteria has implications for therapeutic strategies in patients with earlyand advanced stages of disease. Monitoring inflammatorycytokines (IL-6) in relation to endotoxin values instool appears of limited clinical value in controlling this devastating disease in pretermneonates.

Importance of Colonization Site in the Current Epidemic of Staphylococcal Skin Abscesses

OBJECTIVE: The goal was to compare rectal and nasal Staphylococcus aureus colonization rates and S aureus pulsed-field types (PFTs) for children with S aureus skin and soft-tissue abscesses and normal control subjects. METHODS: Sixty consecutive children with S aureus skin and soft-tissue abscesses that required surgical drainage and 90 control subjects were enrolled. Cultures of the nares and rectum were taken in both groups. S aureus isolates from all sites were characterized through multiple-locus, variable-number, tandem-repeat analysis, pulsed-field gel electrophoresis, staphylococcal cassette chromosome mec typing for methicillin-resistant S aureus isolates, and determination of the presence of Panton-Valentine leukocidin genes. RESULTS: S aureus was detected significantly more often in the rectum of children with abscesses (47%) compared with those in the control group (1%; P = .0001). Rates of nasal colonization with S aureus were equivalent for children with abscesses (27%) and control subjects (20%; P = .33). S aureus recovered from the rectum was identical to S aureus in the abscess in 88% of cases, compared with 75% of nasal isolates. PFT USA300, staphylococcal cassette chromosome mec type IV, and Panton-Valentine leukocidin genes were significantly increased in the S aureus isolates from children with abscesses compared with those from control subjects. CONCLUSIONS: Skin and soft-tissue abscesses in the current epidemic of community-associated staphylococcal disease are strongly associated with rectal colonization by PFT USA300. Nasal colonization in children does not seem to be a risk factor.

Blood culture results as determinants in the organism identification of bacterial meningitis.

The diagnosis of bacterial meningitis depends on a lumbar puncture (LP). Sometimes, antibiotics are administered before a LP that is delayed owing to prior need for computerized tomography (CT) scan, technical problems, inability to obtain consent, or an unstable patient. We examined the accuracy of blood culture, cerebrospinal fluid (CSF) Grams stain, and antigen detection by latex for organism identification of meningitis. All patients admitted to the Childrens Hospital of Buffalo between January 1, 1984 and December 31, 1989 and having a CSF culture diagnosis of bacterial meningitis had their charts retrospectively reviewed. Patients excluded from the study were those with neural tube defects or CSF catheters, those admitted directly to the Intensive Care Nursery (ICN), those whose positive CSF cultures were determined to be a contaminant, those whose medical records were not found, or those older than 16 years. We analyzed a total of 178 patients with positive CSF cultures and the confirmed diagnosis of bacterial meningitis. Of 169 patients who had a blood culture performed, 86% had the organism responsible for meningitis recovered by this test, with the highest yield of 91% occurring in the 2.5-month to 24-month age group. Blood culture identified the bacteria in 94% of those patients with Haemophilus influenzae meningitis, and this yield increased to 100% when patients who had been pretreated with antibiotics were excluded. The combination of blood culture, CSF Grams stain, and/or latex agglutination identified the causative bacteria in 92% of patients with meningitis. Blood culture, CSF Grams stain, and latex agglutination are useful in identifying the organism causing pediatric meningitis.(ABSTRACT TRUNCATED AT 250 WORDS)

In Vitro Growth Responses of Bifidobacteria and Enteropathogens to Bovine and Human Lactoferrin

A series of In vitro experiments was performed to test the ability of bovine and human lactoferrin to influence the growth of the gram-positive probiotic bacteria, Bifidobacterium bifidum, Bifidobacterium infantis, and Lactobacillus acidophilus, as well as the gram-negative enteric bacteria, E. coli O157:H7 and Salmonella typhimurium. None of the lactoferrin preparations stimulated the growth of the tested strains. However, iron-free apo-lactoferrin (bovine and human) and 66% iron-saturated bovine lactoferrin dramatically slowed the growth of E. coli O157:H7 in single culture experiments, while 98% iron-saturated preparations had no effect. In coculture experiments of B. infantis and E. coli, the iron-limited preparations of lactoferrin also slowed the growth of the latter without inhibiting the bifidobacteria. These results suggest that lactoferrin in iron-limited forms may have the potential to be combined with probiotic bacteria in biotherapeutic products, which could help balance human gut microflora and limit the overgrowth of certain enteric microorganisms.

Molecular Typing of Paired Bacterial Isolates From the Adenoid and Lateral Wall of the Nose in Children Undergoing Adenoidectomy: Implications in Acute Rhinosinusitis

OBJECTIVE: Recent studies have suggested that the origin of bacteria that enter the lateral wall of the nose and paranasal sinuses arise from the nasopharynx. The purpose of this study was to compare the molecular biological profiles of potential pathogens found in the nasopharynx and lateral wall of the nose concomittantly in children undergoing surgery for upper respiratory tract disease. STUDY DESIGN AND SETTING: Fifty-two children undergoing adenoidectomy for either tonsillectomy or adenoidectomy (hypertrophy) or otitis media with effusion were studied. Bacterial cultures were taken from the crypts of the adenoids and from the lateral wall of the nose under endoscopic control after sterilization of the vestibule and inferior turbinate. Routine cultures of these areas were performed in the bacteriology laboratory of the Childrens Hospital of Buffalo. RESULTS: Bacterial pathogens were isolated from 79% of adenoids and 46% of lateral walls of the nose. Molecular typing of pairs of nontypable Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis revealed that in 16 of 18 pairs (89%) the identical strain was present in both sites simultaneously. CONCLUSIONS: These results support the concept that when potential bacterial pathogens that may cause acute bacterial rhinosinusitis are found con-comitantly in the nasopharynx and lateral wall of the nose, they are usually identical.

Further observations on the role of Staphylococcus aureus exotoxins and IgE in the pathogenesis of nasal polyposis.

Recent studies have suggested that Staphylococcus aureus secrete exotoxins that may act as superantigens and upregulate the variable beta region of lymphocytes in chronic hyperplasticsinusitis with nasal polyposis (CHSwNP). The aim of this study was to add further information for correlating the presence of staphylococcal species and the upregulation of the Vβ region of both nasal polyp lymphocytes and peripheral blood lymphocytes. Furthermore, IgE‐mediated hypersensitivity directed against these exotoxins produces an additional independent immunologic mechanism in upregulating the inflammatory response in the lateral wall of the nose in nasal polyposis.

Pseudomonas aeruginosa from patients with cystic fibrosis affects function of pulmonary surfactant.

Patients with cystic fibrosis are severely affected by an infection with Pseudomonas aeruginosa, a microbe known to synthesize phospholipase C. This study was designed to determine whether that enzyme would affect the function of pulmonary surfactant phospholipids. Mucoid and nonmucoid strains of P. aeruginosa, freshly obtained from patients with cystic fibrosis, were cultured for 12 h on agar plates. The bacteria were suspended in saline solution and then pelleted by centrifugation. The supernatant was used to dilute the surfactant preparation, calf lung surfactant extract, from 35 to 2 mg/mL. Surfactant function, before and after incubation, was examined with a capillary surfactometer, an instrument specifically developed for an evaluation of the ability of surfactant to maintain patency of a narrow glass tube, simulating a terminal conducting airway. Phospholipid hydrolysis was also evaluated biochemically by determining the total content of phospholipids in surfactant before and after incubation. In five experiments, the lipids were separated with thin-layer chromatography, and the phosphorus content was determined in the diacylphosphatidylcholine band before and after incubation for 6, 24, and 48 h. Capillary openness and phospholipid concentration decreased as enzyme concentration and time of incubation increased (p < 0.0001). Linear regression showed a significant correlation between time of capillary openness and phospholipid concentration (r = 0.957;p < 0.0001). Calf lung surfactant extract hydrolysis was catalyzed by extracts of the bacteria, particularly the nonmucoid, analogous to the catalysis observed with phospholipase C. Surfactant hydrolysis catalyzed by enzymes from P. aeruginosa might severely affect surfactant function provided enzyme concentration is high and time of incubation is long.