Pathogenicity of encapsulated Bacteroides melaninogenicus group, B. oralis and B. ruminicola subsp. brevis in abscesses in mice

The pathogenicity of 27 clinical isolates of the Bacteroides melaninogenicus (BM) group and four clinical isolates of B. oralis and B. ruminicola subsp. brevis were investigated by inoculating them into mice and subsequently determining their ability to cause subcutaneous (SC) or intraperitoneal abscesses. Only ii isolates of BM group and one B. ruminicola induced abscesses in mice, and all were found to be heavily encapsulated on recovery from the abscesses (more than 50 per cent of the organisms were encapsulated). When the other 23 isolates, however, were injected SC in combination with either Klebsiella pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus or Streptococcus pyogenes, abscesses were formed in 16 of the 23 combinations. The Bacteroides spp. recovered from the mixed infection were heavily encapsulated. Capsules also formed in Bacteroides if the organisms were injected together with capsular material or formalin killed cells of K. pneumoniae or encapsulated Bacteroides sp. Once non-encapsulated or only slightly encapsulated strains acquired a capsule, they could induce abscesses on reinoculation into mice.     

Relative importance, seasonal variation, O- and K-antigens of enterotoxigenic Escherichia coli: A three-and-a-half year review in Sweden

From January 1976 to June 1979, 3510 specimens from patients with diarrhoea in Sweden were tested for the presence of heat-labile enterotoxin producing Esch. coli and other enterotoxigenic Enterobacteriaceae (ETEB). ETEB were found in 76 patients (2·2 per cent). Of these, 18 were children under two years of age, constituting 2·6 per cent of all infants. Ninety per cent of the adult patients and 56 per cent of the children with ETEB had contracted diarrhoea in association with travel abroad. The incidence of isolation of ETEB reached a peak in August with an average of 7·2 per cent. From a proportion of our patients, i.e. 727 patients with diarrhoea who attended a hospital for infectious diseases (Roslagstull Hospital) during the last 12 months of the study, data were collected concerning where they had contracted diarrhoea and what other enteric pathogens had been isolated from their faeces. Sixty-five per cent of these patients had been travelling. An enteric pathogen was demonstrated in 44 per cent of the patients who had travelled and ETEB were found in 6·2 per cent of such patients. An enteric pathogen was demonstrated in 12 per cent of those who had not been travelling and no ETEB were isolated from these patients. Among the enterotoxigenic Esch. coli the O-antigens 06 and 025 dominated and were found in 44 per cent of the patients with enterotoxigenic Esch. coli. Esch. coli 06:K15 was found in patients from many different parts of the world. No enterotoxigenic strain of Esch. coli 078 was identified. It is concluded from this study that ETEB-associated diarrhoea is only occasionally contracted in Sweden but constitutes an important finding in travellers' diarrhoea.     

Emergence of SCCmec Type IV as the Most Common Type of Methicillin-Resistant Staphylococcus aureus in a University Hospital

Abstract Background:   The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) has dramatically changed over the last decade by the emergence of community-associated MRSA (CA-MRSA). Recent studies indicate that these strains have already spread to hospitals. To evaluate if SCCmec type IV and Panton–Valentine leukocidin (PVL) are unambiguous markers of CA-MRSA, we analyzed 77 sporadic MRSA strains isolated, in our low MRSA incidence university hospital, from inpatients between 2000 and 2004. Methods:   MRSA strains were analyzed by staphylococcal cassette chromosome mmecec (SCCmec) typing, PCR for PVL genes and pulsed-field gel electrophoresis (PFGE). MRSA was classified in HA-MRSA or CA-MRSA according to Centers for Disease Control and Prevention (CDC) criteria. Antimicrobial susceptibility testing was performed using microbroth dilution method following CLSI recommendations. Results:   Among 77 sporadic single-patient strains, SCCmec types I–IV and four subtypes were identified. Type IV/IVA was most common (42.9%).The distribution of SCCmec types changed over the years. Type IV/IVA strains increased from 33.3% in 2000 to 57.9% in 2004. Type IV strains were resistant to ciprofloxacin in 81.8%, and in 9.1% to tobramycin while type IVA strains were 100% resistant to both antimicrobials. In contrast, non-type IV/IVA strains were resistant to ciprofloxacin in 86.4%, and in 75.0% to tobramycin. Only one strain was PVL positive and harbored SCCmec type III variant. By PFGE analysis, the 33 SCCmec type IV/IVA strains comprised 12 distinct genotypes. 36.4% of 11 CA-MRSA and 43.9% of 66 HA-MRSA harbored SCCmec type IV/IVA. Conclusion:   Type IV/IVA has become the most common SCCmec type in inpatients of our university hospital. The SCCmec type IV/IVA is present in both CA-MRSA and HA-MRSA limiting its use as a marker for CA-MRSA.     

Active perfringocin typing of food poisoning strains of Clostridium perfringens type A--a new tool for epidemiological investigations

Active perfringocin typing, as an epidemiological tool, for investigation into food poisoning outbreaks due to C. perfringens type A has been developed. Ninety strains included in this study were from England, America, India, Japan, France and Canada Nine indicator strains exhibiting different patterns of inhibition were selected for perfringocin typing. With these indicator strains, 81.11 per cent of the strains were typable into ten perfringocin types. Type "a" and "b" alone could type 47.92 per cent of the strains. Type "f" was predominantly found to be for the American strains and "b" and "c" for the Indian strains. Active perfringocin typing developed for the first time for the food poisoning strains of C. perfringens type A was expected to prove useful in the epidemiological investigations.     

Questionable specificity of lipid antigen in the Mycoplasma pneumoniae complement fixation test in patients with extrapulmonary manifestations

The clinical spectrum in serologically verified Mycoplasma pneumoniae infections was studied in a series of 387 in-patients traced from the laboratory records of mycoplasmal and viral screening tests. The proportion of patients with extrapulmonary manifestations was unexpectedly high, 115 (29·7 per cent). Of these, 69 patients (17·8 per cent) had only non-respiratory manifestations. Two hundred and seventy-two patients (70·3 per cent) had respiratory symptoms only, without extrapulmonary complications.The commonest complications of respiratory infection due to M. pneumoniae were carditis and central nervous system infections. In the group without respiratory symptoms the heart, the central nervous system and the gastro-intestinal tract were most commonly affected. Some laboratory and epidemiological features of patients with respiratory infection only were compared with those of patients with respiratory infection and some extrapulmonary complication and with those of patients who had extrapulmonary manifestations only. Differences were found between the first and third groups, whereas the first and second groups resembled each other.The explanation of these differences, and of the unexpectedly high frequency of extrapulmonary manifestations may be lack of specificity of the complement fixation test with glycolipid antigen used for diagnosis.     

Cellulitis in children caused by Haemophilis influenzae type b

Of 31 episodes of invasive infection by Haemophilus influenzae capsular type b, occurring in children during a 26-month period, five (16 per cent) had cellulitis as the presenting feature. In four of the five patients bacteraemia was detected. This frequency of presentation is not reflected in reports in the British literature. Prompt recognition of this aetiology of cellulitis is important for effective chemotherapy.     

Molecular analysis of Mycobacterium tuberculosis from tuberculous meningitis patients in Thailand

The first retrospective molecular characterization of Mycobacterium tuberculosis from cerebrospinal fluid of 158 tuberculous meningitis (TBM) in Thailand, collected between 1995 and 2005, was performed by Southern-blot hybridization with an IS6110 probe and spoligotyping on 152 and 147 isolates, respectively. Antituberculous drug susceptibility testing was performed in 149 patients, 118 of whom (79.2%) contained pan-sensitive strains and eight (5.4%) harbored multidrug-resistant M. tuberculosis. IS6110 RFLP typing revealed 110 RFLP patterns with 57.9% of patients infected with the Beijing genotype. This percentage was significantly higher than that in a previous report from pulmonary tuberculosis patients. Fifteen of 18 TBM patients (83%) aged <15 years were infected with Beijing isolates (OR = 4.47, p = 0.018). There were 40 spoligotypes, with 118 patients (80.3%) being clustered. The biggest cluster, which consisted of 84 patients, was the Beijing spoligotype (57.1%). There were 16 novel spoligotypes from 16 patients compared to the Fourth International Spoligotyping Database, SpolDB4. Sixty-four percent of the patients were male, and the mean age of patients was 33.8 years. Beijing isolates from 2001 to 2005 were found in higher percentages than those from 1995 to 2000, but this difference was not significant (p = 0.28).     

Isolation of C. diphtheriae gravis in Leeds

Four isolations of Corynebacterium diphtheriae gravis were made in Leeds over three weeks in the early part of 1980. The first three isolations were made independently and the fourth was a close family contact of the third. Only the first isolate was shown to be toxigenic and could be distinguished from the others by phage typing but all were indistinguishable otherwise by biotyping and bacteriocin typing. Detailed epidemiological investigation failed to establish any connection among the three incidents, or any other positive contacts. Five months later, C. diphtheriae gravis was isolated from a five-month-old infant and from 17 other individuals during contact screening. All 18 isolates from this episode were shown to be non-toxigenic and were indistinguishable by biotyping and bacteriocin typing.     

The prevalence of post-traumatic stress disorder and its relation to childhood adversity in subjects with eating disorders

The prevalence of post-traumatic stress disorder (PTSD) and its relation to childhood adversity and Axis I psychiatric disorders was assessed in a clinical population of 164 eating disorders patients. Eleven per cent (18/164) had a lifetime history of PTSD. There was no difference in the prevalence of PTSD between the subgroups of eating disorders. Higher prevalences of PTSD symptoms were found in those who had a history of childhood sexual abuse (23 per cent versus 9 per cent; p<0.05), discord in the home (16 per cent versus 6 per cent; p<0.05) and high parental control (44 per cent versus 6 per cent; p<0.001). Higher rates of life-time comorbidity of other Axis I disorders in PTSD sufferers was only found for anxiety disorders (67 per cent versus 39 per cent, p<0.03). Possible mechanisms linking childhood experiences to PTSD are discussed. © 1997 John Wiley & Sons, Ltd and Eating Disorders Association.     

Inhibition of fungal growth by Pseudomonas aeruginosa and Pseudomonas cepacia isolated from patients with cystic fibrosis

This study was undertaken because of the infrequency of infections due to Candida species in patients with cystic fibrosis despite their extensive treatment with broad-spectrum antibiotics. In vitro susceptibility studies revealed significant inhibition of 11 strains of fungi known to infect human beings by 10 strains of Pseudomonas aeruginosa and nine strains of Pseudomonas cepacia isolated from the sputum of patients with cystic fibrosis. The fungi were Candida krusei, Candida keyfr, Candida guillermondii, Candida tropicalis, Candida lusitaniae, Candida parapsilosis, Candida pseudotropicalis, Candida albicans, Torulopsis glabrata, Saccharomyces cerevisiae and Aspergillus fumigatus. Inhibition of fungal growth by Escherichia coli (NCTC 10418), Staphylococcus aureus (NCTC 6571) and Haemophilus influenzae (NCTC 11931) could not be demonstrated. The continued presence in the sputum of patients with cystic fibrosis of strains of P. aeruginosa and P. cepacia, which produce antifungal substances, may inhibit growth of Candida species and so prevent overt Candida infections. A. fumigatus would seem to be the most important fungus causing disease in patients with cystic fibrosis. It is therefore interesting to note that this was the most resistant of all the fungi tested for inhibition by P. aeruginosa and P. cepacia.     

Helicobacter pylori cagA Status and Peptic Ulcer Disease in Iran

Helicobacter pylori contributes to the development of peptic ulcers and atrophic gastritis. Furthermore, H. pylori strains carrying the cagA gene are more virulent than cagA -negative strains and are associated with the development of gastric adenocarcinoma. The cagA gene is a putative H. pylori virulence factor of unknown function. The aim of this study was to determine the prevalence of the cagA gene among H. pylori isolates and its relationship with peptic ulcer disease in 128 Iranian patients. A total of 107 (83.6%) samples were positive, including 40 (95%) of the 42 patients with duodenal ulcer, 43 (86%) of the 50 patients with gastric ulcer, and 24 (66.6%) of the 36 patients with gastritis. cagA was present in 32 (80%) of 40 strains from duodenal ulcer patients, 33 (77%) of 43 strains from gastric ulcer patients, and 11 (46%) of 24 from gastritis patients. We also attempted to investigate the subtypes of 3′ region of cagA gene in H. pylori strains isolated from Iranian patients and their relation to H. pylori-associated gastroduodenal diseases. The PCR product of cagA positive strains obtained with primer set CAG1/CAG2 differed in size, varying from 642 to 651 bp (subtype A) in 33 isolates to 756 bp (subtype B/D) in 13 isolates. This does not support the view that subtypes of the 3′ region of cagA gene in H. pylori isolated from Iran correlate with the clinical outcomes of H. pylori, but colonization with cagA positive strains was significantly higher among duodenal ulcer than gastritis patients in Iran.     

Nosocomial infections by chlorhexidine solution contaminated with Pseudomonas pickettii (Biovar VA-1)

Over a period of io days, six patients in a cardiac intensive care unit developed Pseudomonas pickettii (biovar VA-1) septicaemia after installation of a venous catheter. The organism was also recovered from all the vials of the aqueous solution of 0·05 per cent chlorhexidine (‘Hibitane’) prepared with contaminated bidistilled water. There were no further cases of infection when the use of this water was prohibited.     

Phenotypic and Genotypic Characterization of Helicobacter pylori from Patients with and without Peptic Ulcer Disease

Background: Helicobacter pylori plays an important role in peptic ulcer disease, although not all H. pylori-infected persons will develop a peptic ulcer. Currently, H. pylori strains cannot be divided into commensals and pathogens. Methods: Fifty H. pylori strains were cultured from patients divided into five groups on the basis of upper endoscopic findings: gastric ulcer, duodenal ulcer, gastritis, esophagitis, or normal. The ultrastructural adherence pattern in vivo, autoagglutination, hemagglutination, adhesion to human gastric adenocarcinoma (AGS) cells, and the lipopolysaccharide (LPS) profile of H. pylori strains were recorded; randomly amplified polymorphic DNA (RAPD) and urease gene typing were performed and correlated with diagnostic groups. Results: Electron micrographs showed that H. pylori strains from patients with gastric ulcers adhered more frequently through filamentous strands and were less frequently found free in mucus than any other diagnostic group (P &lt; 0.0001). Neither median hemagglutination titer nor median adhesion capacity to a human gastric adenocarcinoma cell line was related to endoscopic findings. Nevertheless, H. pylori strains from patients with gastric ulcers were more prone to autoagglutinate than were strains from the other diagnostic groups (P = 0.03). H. pylori strains from gastric ulcer patients were found to be more homogeneous, as determined by RAPD and urease gene typing, than strains from the other diagnostic groups (P &lt; 0.01). In addition, a positive correlation was found between a patient's age and the adhesion to AGS cells of the patient's H. pylori strain (P = 0.006). Conclusion: A combination of an H. pylori autoagglutination test, RAPD, and urease gene typing may be useful in separating gastric ulcer-related strains from duodenal ulcer-related and non-ulcer dyspepsia-related strains.     

Molecular epidemiology and evolutionary genetics of Mycobacterium tuberculosis in Taipei

Background  

The control of tuberculosis in densely populated cities is complicated by close human-to-human contacts and potential transmission of pathogens from multiple sources. We conducted a molecular epidemiologic analysis of 356 Mycobacterium tuberculosis (MTB) isolates from patients presenting pulmonary tuberculosis in metropolitan Taipei. Classical antibiogram studies and genetic characterization, using mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) typing and spoligotyping, were applied after culture.     

Life span alteration after irradiation in Drosophila melanogaster strains with mutations of Hsf and Hsps

The life span alteration after γ-irradiation and/or paraquat treatment in Drosophila in wild type strain Canton-S and strains with mutations of heat shock factor (1–4 alleles) and heat shock proteins (Hsp70Ba ³⁰⁴ , Hsp83 ^e6A , Hsp22 ^EY09909 , Hsp67Bb ^EY099099 ) was investigated. Chronic low-dose rate γ-irradiation (0.017 and 0.17 cGy/h) on pre-imago stages was used as a priming dose (absorbed doses were 4 and 40 cGy). Paraquat, a free radical inducing agent, was a challenging factor (20 mM for 1 day). It was shown that chronic irradiation led to adaptive response in both sexes except homozygous males and females with mutations of Hsf ⁴ and Hsp70Ba ³⁰⁴ . The gender-specific differences in stress response were discovered in wild type strain Canton-S, Hsp22 ^EY09909 Hsp67Bb ^EY09909 homozygotes and Hsp83 ^e6A heterozygotes: the adaptive response persisted in males, but not in females. Thus, Drosophila Hsp and Hsf mutation homozygotes did not demonstrate the adaptive response in the majority of cases, implying an important role of those genes in radiation hormesis and adaptation to stresses.     

The influence of probanthine upon the gastric secretion of HCl and pepsin in patients with peptic ulcers

Summary 1. The influence on the basal gastric secretion of 50 mg. of Probanthine, administered orally 30 minutes before intubation and after histamine, was observed in 14 patients.2. The average concentration of pepsin fell by 39 per cent in the basal secretion, and by 37 per cent after histamine (P<0.01).3. The total output of pepsin fell by 40 per cent in the basal secretion (P<0.01), and by 54 per cent in the secretion after histamine (P<0.001).4. The quantity of the gastric juice fell by 43 per cent after the administration of histamine (P<0.001), while the decrease of the basal secretion was not significant (P>0.05).5. Probanthine did not influence the acidity of the gastric juice substantially. A decrease of 6 to 9 per cent is not considered significant.     

Presence of adherent Escherichia coli strains in ileal mucosa of patients with Crohn's disease

Background & Aims: Infectious agents are suspected of being involved in the pathogenesis of Crohn's disease. This study was designed to look for the presence of virulent Escherichia coli strains associated with the ileal mucosa of patients with Crohn's disease. Methods:E. coli strains were recovered from resected chronic ileal lesions (n = 20), neoterminal ileum after surgery from patients with (n = 19) and without (n = 11) endoscopic recurrence, and controls (n = 13). Bacterial adhesion was determined in vitro using intestinal cell lines; other associated virulence factors were assessed by DNA hybridization and polymerase chain reaction experiments. Results: None of the strains harbored any of the virulence factor–encoding genes of E. coli involved in acute enteric diseases. However, mannose-resistant adhesion to differentiated Caco-2 cells was found for 84.6% and 78.9% of the E. coli strains isolated from chronic and early recurrent lesions, respectively, compared with 33% of controls (P < 0.02). In addition, 21.8% of the strains induced a cytolytic effect by synthesis of an α-hemolysin. Conclusions:E. coli strains isolated from the ileal mucosa of patients with Crohn's disease adhere to differentiated intestinal cells and may disrupt the intestinal barrier by synthesizing an α-hemolysin.GASTROENTEROLOGY 1998;115:1405-1413     

Survival in acute obstructing colorectal carcinoma

Acute intestinal obstruction was the presenting feature in 124 (19 per cent) of 646 patients with colorectal carcinoma seen over a six-year period. Forty-two per cent of tumors were incurable at presentation. Obstruction was complicated by perforation in 22 patients (18 per cent). Only 15 per cent of tumors occurred in the rectum. Although the postoperative mortality rate was higher in patients with coincidental perforation than in those without (52 vs. 26 per cent:P=0.03), five-year survival rates were the same: 18 per cent overall, rising to 29 to 34 per cent after “curative” resection. Five-year survival rates were best for right colon tumors and worst for rectal tumors (36 vs. 5 per cent:P=0.01). The overall hospital mortality rates for colostomy and delayed resection, resection with colostomy, and resection with anastomosis were equivalent (18 to 22 per cent), but following “curative” resection the hospital mortality rate was higher for resection with colostomy than with other treatments (29 vs. 15 per cent), since two patients died following early colosure of colostomy. Five-year survival was better following resection with anastomosis (48 per cent) than staged procedures (18 per cent:P=0.01), since two patients died following late closure of colostomy.     

Heterogeneity in expression of lipopolysaccharides by strains of Escherichia coli O157

A total of 47 strains of Escherichia coli belonging to serogroup O157 were examined for the expression of long-chain lipopolysaccharide (LPS) by means of SDS—PAGE and silver staining. Strains belonged to 10 different flagellar (H) types or did not express flagella. Nine strains carried genes encoding Vero cytotoxin (VT). Strains of E. coli O157 expressed one of three LPS SDS—PAGE profiles designated A, B and C. Strains expressing profile A belonged to H-types 6 and 19, while those expressing LPS profile B belonged to H-types 2, 16, 20, 39, 42 and 45. Strains of E. coli expressing profile C belonged to H-types 7 and 8; strains producing VT expressed LPS profile C only, although not all strains with H-types 7 and 8 carried genes for VT. Regardless of H-type or the LPS profile expressed, serum antibodies produced by patients infected with strains of E. coli belonging to serogroup O157 would be detected by serological tests.     

The Relationship of Age, Strain and Species to the Reducing Activity of Leukocytes

A method is presented for studying the reducing activity of leukocytes ofmice and rats using 2-(p-iodophenyl)-3-)p-nitrophenyl)-5-phenyltetrazoliumchloride (INT).

Between 48.0 per cent and 83.8 per cent of the leukocytes of young adultmice and between 47.8 per cent and 68.0 per cent of the leukocytes of youngrats showed formazan formation.

Infant mice of C3H_f and BALB_f strains had appreciably fewer leukocyteswith the ability to reduce tetrazolium than did young adults of their respectivestrains.

Healthy adult mice belonging to the leukemia susceptible AKR strain showeda relatively high degree of leukocytic reduction.

Old mice of the C3H_fstrain showed less formazan formation than youngadult animals. This decrease was more marked for the male members of thespecies.

Submitted on October 15, 1958 Accepted on January 12, 1959