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PubMed1994

[Studies on respiratory infections in primary care clinic (V). The pattern of distribution on bacteria, Mycoplasma pneumoniae and virus isolated from patients with respiratory infections, who were seen in six private clinics, and clinical efficacy of ciprofloxacin and roxithromycin].

The pattern of distribution of bacteria, Mycoplasma pneumoniae and virus isolated from the same specimen recovered from the throat swab or the sputum of 479 patients with respiratory infections who were seen in six private clinics in Sendai City of Japan during the period from October to November in 1992 (period I) and from January to February in 1993 (period II) was documented. Of the 479 patients, 234 had acute pharyngitis, 145 had acute bronchitis, 96 had influenza, 21 had acute tonsillitis, 5 had acute pneumonia and 9 had other respiratory infections. One hundred (42.4%) strains of potential pathogen and one strain of M. pneumoniae were recovered from 236 cases in period I, and 66 (27.2%) strains of potential pathogen, one strain of M. pneumonae and 73 strains of Influenza virus (30.0%: 43 of type A Hong-Kong and 30 of type B) from 243 cases in period II. Of the 166 strains, major isolates were Staphylococcus aureus (56 strains), Streptococcus pneumoniae (12 strains), Streptococcus pyogenes (15 strains), Haemophilus influenzae (17 strains), Esherichia coli (4 strains), Klebsiella spp. (35 strains), Pseudomonas aeruginosa (4 strains) and Acinetobacter spp. (23 strains). Only one strain of S. aureus was resistant to methicillin (MIC: 50 micrograms/ml). None of S. pneumoniae was resistant to 1 microgram/ml of ampicillin. Ciprofloxacin was administered to 113 cases and roxythromycin to 220 cases by doctors in charge.(ABSTRACT TRUNCATED AT 250 WORDS)

Ciprofloxacin↗
PubMed1996

Contemporary testing for enteric pathogens: the potential for cost, time, and health care savings.

We sent a questionnaire to 79 clinical microbiology laboratories seeking information on contemporary practices when investigating for bacterial and protozoan enteric pathogens. Data from the 67 respondents (response rate of 85%) showed that a minority of laboratories (40% for stool culture and 45% for ova and parasite [O&P] examinations) had restrictions for testing in place and that fewer laboratories (24% for stool culture and 19% for O&P examinations) rejected specimens from patients who had been in the hospital for > 3 days. Using two estimates, 15 and 40%, for the proportion of all specimens received from patients in the hospital for > 3 days, we calculated savings for the average hospital in this survey. Reagent savings of $4,000 to $10,000 and time savings of 274 to 731 h per year might have been realized. Moreover, between $26,000 and $71,000 in patient charges could have been prevented. On the basis of this survey, wider application of rejection criteria when testing for enteric pathogens appears possible. If implemented, savings to the nation's health care system could be between $27 and $73 million a year.

Animals↗
PubMed2006

Molecular and cellular basis for pathogenicity of autoantibodies: lessons from murine monoclonal autoantibodies.

The pathogenesis of autoantibody-mediated cellular and tissue lesions in autoimmune diseases is most straightforwardly attributable to the combined action of self-antigen binding properties and effector functions associated with the Fc regions of the different immunoglobulin (Ig) isotypes. The analysis of two different sets of monoclonal autoantibodies derived from lupus-prone mice revealed remarkable differences in the pathogenic potentials of different IgG subclasses: (1) the IgG2a and IgG2b subclasses of anti-red blood cell (RBC) autoantibodies are the most pathogenic and efficiently activate two classes of activating IgG Fc receptors (FcgammaRIII and FcgammaRIV) and complement; (2) the IgG3 subclass is less pathogenic and activate only complement; and (3) the IgG1 subclass is the least pathogenic and interact only with FcgammaRIII. In addition, because of the unique property of IgG3 to form self-associating complexes and generate cryoglobulins, this subclass of rheumatoid factor and anti-DNA autoantibodies became highly pathogenic and induced lupus-like nephritis and/or vasculitis. Since the switch to IgG2a and IgG3 is promoted by Th1 cytokine interferon gamma, these results strongly suggest that Th1 autoimmune responses could be critically involved in the generation of more pathogenic autoantibodies in systemic lupus erythematosus. This finding is consistent with the observation that the progression of murine lupus nephritis is correlated with the relative dominance of Th1 autoimmune responses. Finally, the analysis of IgG glycosylation pattern revealed that more sialylated IgG autoantibodies remained poorly pathogenic because of limited Fc-associated effector functions and loss of cryoglobulin activity. This suggests that the terminal sialylation of the oligosaccharide side chains of IgG could be a significant factor determining the pathogenic potential of autoantibodies. Our results thus underline the importance of subpopulations of autoantibodies, induced by the help of Th1 cells, in the pathogenesis of autoantibody-mediated cellular and tissue injuries.

Animals↗
PubMed1990

Virulence attributes of the liposaccharides of the HAP group organisms.

The pathogenic potential of purified gram-negative bacterial endotoxin is well documented. However, the role of endotoxin in the disease producing ability of pathogenic organisms, including those of the HAP group, remains in doubt. Endotoxin is not a classic virulence factor, but likely contributes to the pathogenic potential of gram-negative bacteria by activation of host defensive systems which ultimately results in the clinical signs and tissue damage that we recognize as disease. On the other hand, the proinflammatory nature of endotoxin, as well as liposaccharide antigens, play a critical role in the successful elimination of the infecting organism. How the induction of host defensive systems by endotoxin might benefit the infecting organism is difficult to reconcile. In this regard, host response to endotoxin often appears to be in excess of that necessary to clear the infection. Regardless of the role endotoxin might play in the pathogenesis of an infection, liposaccharide antigens are important in the serologically based classification of bacterial strains, are known to contribute to protective immunity, and are useful in the serological diagnosis of infection.

Animals↗
PubMed1980

Pathogenic properties of Yersinia enterocolitica.

A total of 88 isolates of Yersinia enterocolitica was examined for heat-stable enterotoxin production and ability to penetrate HeLa cells and evoke keratoconjunctivitis in guinea pigs (Séreny test) as potential pathogenic properties. All 49 isolates belonging to serotypes O:3, O:8, O:9, and O:5,27 and only 5 of 39 strains of other serotypes were HeLa positive. Séreny-positive strains were found only in serotype O:8. Heat-stable enterotoxin production was almost ubiquitous in all serotypes. Y. enterocolitica strains were classified into five groups with regard to their potential pathogenic properties.

Animals↗
PubMed1997

Increased lymphomagenicity and restored disease specificity of AML1 site (core) mutant SL3-3 murine leukemia virus by a second-site enhancer variant evolved in vivo.

SL3-3 is a highly T-lymphomagenic murine retrovirus. The major genetic determinant of disease is the transcriptional enhancer, which consists of a repeated region with densely packed binding sites for several transcription factors, including AML1 (also known as core binding factor and polyoma enhancer-binding protein 2) and nuclear factor 1 (NF1). Previously, we examined the enhancer structure of proviruses from murine tumors induced by SL3-3 with mutated AML1 (core) sites and found a few cases of second-site alterations. These consisted of deletions involving the NF1 sites and alterations in overall number of repeat elements, and they conferred increased enhancer strength in transient transcription assays. We have now tested the pathogenicity of a virus harboring one such second-site variant enhancer in inbred NMRI mice. It induced lymphomas with a 100% incidence and a significantly shorter latency than the AML1 mutant it evolved from. The enhancer structure thus represents the selection for a more tumorigenic virus variant during the pathogenic process. Sequencing of provirus from the induced tumors showed the new enhancer variant to be genetically stable. Also, Southern blotting showed that the tumors induced by the variant were T-cell lymphomas, as were the wild-type-induced lymphomas. In contrast, tumors induced by the original core/AML1 site I-II mutant appeared to be of non-T-cell origin and several proviral genomes with altered enhancer regions could be found in the tumors. Moreover, reporter constructs with the new tumor-derived variant could not be transactivated by AML1 in cotransfection experiments as could the wild type. These results emphasize the importance of both core/AML1 site I and site II for the pathogenic potential of SL3-3 and at the same time show that second-site alterations can form a viral variant with a substantial pathogenic potential although both AML1 sites I and II are nonfunctional.

Animals↗
PubMed1993

Bacteriology and immunology of normal and diseased adenoids in children.

Adenoid physiology as reflected in the qualitative and quantitative bacteriology and immune cell distribution was correlated with clinical presentation in 69 children (16 to 130 months of age) undergoing adenoidectomy for obstructive adenoid hyperplasia (n = 38) or chronic adenoid infection (n = 31) and in 16 adenoid core biopsy specimens from 16 nondiseased controls. In the control adenoids, few potentially pathogenic bacteria were found as the dominant bacteria in the adenoid core (25%), and significantly greater concentrations of nonpathogens (commensals) were isolated (P < .01). Potential pathogens as the dominant bacteria were found twice as often in obstructive adenoid hyperplasia (62%) and in chronic adenoid infection (55%) (P < .05). Haemophilus influenzae was most common in the diseased adenoids, 53% in obstructive adenoid hyperplasia and 48% in chronic adenoid infection, compared with only 19% in the controls (P < .05). No significant differences in lymphocyte density, B and T cells, as well as T-helper subsets, were found between clinical classifications. However, T-suppressor cells, monocytes-macrophages, and natural killer cells were significantly increased in chronic adenoid infection only (P < .05). The findings in this study support roles for both alterations in bacterial homeostasis and an altered immune profile in the etiology of chronic adenoid disease in children.

Adenoids↗
PubMed1978

Early postsurgical bacterial contamination of the airways: a study on 28 open-heart patients.

One pre- and two postoperative cultures of tracheo-bronchial secretions were obtained from 28 cardiac patients, subjected to open-heart surgery. Four patients received preoperative antibiotics, and all but one received postoperative prophylactic antibiotics. Preoperatively, only one patient had potential pathogens; after surgery (mean intubation time 4.2 h), four patients (14.3%) had organisms; and after 19 h of intubation, 28% of the patients had potential pathogens in their tracheo-bronchial secretions. Only three of the seven organisms recovered from the last sample were clearly sensitive to the antibiotics given prophylactically; and two of these organisms were Group A beta-haemolytic streptococci. The early presence of organisms in the airways after intubation, the high incidence of colonization, and the ineffectiveness of prophylactic antibiotics in preventing this contamination are pointed out. The factors that may possibly influence colonization of airways among these patients are commented on.

Adolescent↗
PubMed1987

Evaluation of the experimental pathogenicity of some Cryptococcus species in normal and cyclophosphamide-immunodepressed mice.

The pathogenic potential of distinct Cryptococcus species has been evaluated in mice rendered leukopenic by one or two injections of the potent immunosuppressive drug cyclophosphamide (Cy). Pathogenicity assessment included enumeration of viable cryptococcal cells in animal organs and histopathological observations. It was found that putatively non-pathogenic species of Cryptococcus, in particular C. cereanus and C. albidus, showed significant lethality for Cy-treated mice. In Cy-immunodepressed mice, challenged with the infectious cryptococcal cells two days after pharmacological treatment, a significant decrease of LD50 (equivalent to at least one order of magnitude) was observed for all Cryptococcus species. However, the pathogenicity enhancement due to Cy immunodepression was greater with C. neoformans. In all cases, brain and kidney were the most invaded tissues as also evidenced by histopathological examination, which showed the typical cystic lesion. All the observations made point to the conclusion that the pathogenic potential, for the immunomodulated host, of Cryptococci other than C. neoformans is significant being quantitatively and not qualitatively different from that of C. neoformans, as evidenced by a similar organotropism and similar type of histological lesions in the target organs (brain and kidney).

Animals↗
PubMed1977

Observation on the bacterial population of the os cervix of the ewe before and after embryo death.

Bacterial samples were isolated from the os cervix of mature Merino ewes during a normal oestrous cycle and after colchicine treatment which killed the 25-day old embryos. The population of bacteria was small during the oestrous cycle and consisted of Achromobacter spp. Alcaligenes spp, Corynebacterium spp, Bacillus spp and Escherichia coli. There was a significant increase in the numbers of bacteria isolated and a change in the proportions of the bacteria isolated from ewes after embryo death. Much greater numbers of potentially pathogenic organisms, including Pasteurella multocida, Corynebacterium pyogenes, Staphylococcus spp and Streptococcus spp were isolated after embryos were killed. It is suggested that persistence of potential pathogens in the vagina may impair fertility in ewes at the first oestrus after embryo death.

Animals↗
PubMed1977

Microscopic and bacteriological comparison of paired sputa and transtracheal aspirates.

Ninety-six sputum specimens from patiens with pneumonia were microscopically screened for leukocytes and buccal squamous epithelial (BSE) cells. Cultures of these specimens were compared with cultures of paired transtracheal aspirates (TTA). Agreement between sputa with less than 25 BSE cells per 100X field and TTA was good (79%). Only 27% of the specimens with greater than 25 BSE cells per 100X field agreed with TTA. Sixty-six of the sputa were of group 5 quality, i.e., greater than 25 leukocytes and less than 10 BSE cells per 100X field. A potential pathogen growing in one of these specimens was 94% predictive of growth in the TTA. If a group 5 sputum was negative for a potential pathogen, there was a 45% chance that a fastidious organism had been overgrown or overlooked. The presence of definite lower tract secretions in group 5 sputa as determined by visualizing bronchial epithelial cells and alveolar macrophages did not significantly increase the diagnostic value of these specimens. Microscopic screening of sputum before culture with rejection of selected specimens can increase the value of sputum in determining the etiology of bacterial pneumonia.

Adult↗
PubMed1991

The prevalence of enteric pathogens in diarrhoeic thoroughbred foals in Britain and Ireland.

A survey of 77 normal and 326 diarrhoeic foals in Britain and Ireland from 1987 to 1989 revealed a significantly higher prevalence of Group A rotaviruses and Aeromonas hydrophila in diarrhoeic foals. The prevalence of cryptosporidia, potentially pathogenic Escherichia coli, Yersinia enterocolitica and Clostridium perfringens was similar in normal or diarrhoeic foals. Rotaviruses had a similar prevalence in all age groups of scouring foals up to three months of age, with an overall prevalence of 37 per cent among diarrhoeic foals. The number of cases of diarrhoea varied considerably from year to year, but in all three years of the survey rotavirus was a significant pathogen. A comparison of diagnostic tests for rotavirus in the faeces showed electron microscopy (EM) and polyacrylamide gel electrophoresis (PAGE) to have similar sensitivity. The Rotazyme ELISA test kit was found to have the same sensitivity as a combination of EM and PAGE. A. hydrophila had an overall prevalence of 9 per cent among diarrhoeic foals, although its prevalence was higher in some age groups. A. hydrophila has not been established previously as a significant enteric pathogen in foals. Other putative pathogens found at very low prevalence were coronavirus, the putative picobirnavirus, Campylobacter spp. and Salmonella spp. No evidence was found of synergistic effects between rotavirus, cryptosporidia and potentially pathogenic E. coli. Neither coccidia nor non-Group A rotaviruses were found in any of the samples examined.

Aeromonas↗
PubMed1990

Pathogenesis of colonization and infection in a neonatal surgical unit.

Nosocomial infection with aerobic Gram-negative bacilli is a major cause of morbidity and mortality in neonates. Few prospective studies have been undertaken in neonatal surgical units to investigate colonization and infection rates and the pathogenesis of infection. We prospectively studied 40 infants admitted to a neonatal surgical unit. Ninety-eight percent became colonized in throat/intestine with aerobic Gram-negative bacilli. Thirty-five percent developed infections, with wound and surface infections predominant (61%). Ninety-one percent of infections were caused by Gram-negative bacilli or yeasts. Severe infections (septicemia, pneumonia, meningitis) occurred in 13% of infants. The mortality rate was 5%. In all infections, the pathogenesis was found to be endogenous, and in most, three stages were distinguishable. Neonates always acquired potentially pathogenic organisms in throat/intestine (stage 1) before colonization (stage 2) and infection (stage 3) of other systems occurred. Reduction of digestive tract colonization by these potentially pathogenic microorganisms by means of successful selective decontamination may therefore reduce subsequent infection.

Bacterial Infections↗
PubMed1980

The patient's environment: haven or hazard.

The hospital environment is a complex mix of animate and inanimate components that interact in a myriad of ways to alter the normal flora of a patient, become reservoirs for hospital strains, and provide pathways for transmission of potential pathogens to patients, personnel, and visitors. It is increasingly vital that those responsible for medical and nursing care have the knowledge of normal microbial flora, potential pathogenic organisms, and the routes of transmission through direct or indirect contact, air, or vehicles on which to base responsible decisions. To be effective this knowledge must be incorporated into assessments of individual patients which identify risks and hazards and into daily routine activities (such as handwashing) to block or minimize colonization by hospital strains that can lead to nosocomial infection.

Air Microbiology↗
PubMed2006

Ciprofloxacin-resistant gram-negative bacilli in the fecal microflora of children.

The extent to which antibiotic-resistant bacteria are excreted by humans who have not been exposed to antibiotics is not known. Children, who rarely receive fluoroquinolones, provide opportunities to assess the frequency of fecal excretion by fluoroquinolone-naïve hosts of fluoroquinolone-resistant gram-negative bacilli. Fresh nondiarrheal stools from children were processed by screening them on agar containing ciprofloxacin to recover ciprofloxacin-resistant gram-negative bacilli. Resistant isolates were identified, and ciprofloxacin MICs were determined. Resistant Escherichia coli isolates were also analyzed for urovirulence-associated loci. Thirteen (2.9%) of 455 stools yielded ciprofloxacin-resistant E. coli (seven children), Stenotrophomonas maltophilia (four children), and Achromobacter xylosoxidans and Enterobacter aerogenes (one child each). Neither the subjects themselves nor members of their households used fluoroquinolones in the 4 weeks preceding collection. Six of the seven resistant E. coli isolates belonged to phylogenetic groups B2 and D, in which extraintestinal pathogenic E. coli bacteria are frequently found. All resistant E. coli isolates contained at least three putative E. coli virulence loci. Most ciprofloxacin-resistant bacteria were resistant to additional antibiotics. Potentially pathogenic bacteria that are resistant to therapeutically important antimicrobial agents are excreted by some humans, despite these persons' lack of exposure to the particular drugs. The sources of these resistant organisms are unknown. This underrecognized reservoir of drug-resistant potential pathogens poses public health challenges.

Adolescent↗
PubMed2000

Distribution of airborne bacteria in swine housing facilities and their immediate environment.

This paper describes a bacteriological analysis of air samples taken from swine housing facilities and the immediate environment. The air volume of the samples was pre-programmed by a standard air sampler (MAS-100, Merck) and was directly impacted onto the bacteriologic agar surface (Petri dishes, standard diameter of 90 mm). The bacterial contamination in forty-eight samples was 2.59 x 10(5) CFU/m3 (ranging from 8.46 x 10(4) to 5.30 x 10(5) CFU/m3). Potentially pathogenic bacterial agents predominated in all samples (100%), while primarily pathogenic bacteria were isolated in a minor proportion of samples (33%-66%). Airborne bacterial contamination in samples (N = 16) obtained from emptied facilities ranged from 1.8 x 10(3) CFU/m3 (that is, after coarse mechanical washing) to 0.8 x 10(2) CFU/m3 (upon completion of disinfection). Control measurements at different locations and distance from the farm (N = 32) pointed to the presence of non-pathogenic airborne bacteria, ranging from 1.55 x 10(2) to 3.70 x 10(2) CFU/m3. The results of this preliminary study showed that the emission of potentially pathogenic bacteria from animal housing facilities to the immediate farm environment via aerosol was very low.

Air Microbiology↗
PubMed1988

Keratinophilic fungi on the hair of goats from the West Bank of Jordan.

The mycoflora of the hair in 178 goats from the West Bank of Jordan was analysed and the frequency of occurrence and the relative importance value for the different keratinophilic fungi found were calculated. One hundred and seven species which belong to 38 genera were isolated. Thirty six of these species were either well recognised agents of mycoses (Trichophyton mentagrophytes, T. verrucosum, and M. nanum), or have been frequently isolated from human and animal lesions (Arthroderma spp., Acremonium kiliense, Alternaria alternata, Aspergillus flavus, Cladosporium carionii, and several other species). These potentially pathogenic fungal species comprised 66.9% of all keratinophilic fungi found on the hair of goats. The role of this animal as a reservoir for dermatophytes and other potentially pathogenic fungi is discussed.

Animals↗
PubMed2003

Inadequate salivary flow and poor oral mucosal status in intubated intensive care unit patients.

OBJECTIVE: To investigate salivary flow and frequency of oral mucositis in intensive care unit patients compared with patients admitted because of elective coronary artery bypass graft (CABG) surgery. In addition, the pattern of oropharyngeal colonization was investigated in these patients. DESIGN: Prospective study. SETTING: Mixed intensive care unit and cardiosurgical ward. PATIENTS: In this study, 24 ventilated intensive care unit patients and 20 CABG patients were included. MEASUREMENTS AND MAIN RESULTS: Two dental hygienists examined intensive care unit patients for the presence of periodontal disease and mucositis at admission and subsequently every week during their stay in the intensive care unit. At the same time, stimulated salivary flow and salivary total immunoglobulin A output were measured. Oropharyngeal cultures were obtained as well. CABG patients were examined the day before the operation, 1 day, 1 wk, and 2 wks after the operation. The following results were obtained: a) temporarily reduced postoperative stimulated salivary flow and total salivary immunoglobulin A output in CABG patients and nearly absent stimulated salivary flow in intensive care unit patients; b) oropharyngeal colonization with potentially pathogenic microorganisms in intensive care unit and not in CABG patients; and c) the increase in mucositis index in intensive care unit patients paralleled the increase in potentially pathogenic microorganism oropharyngeal colonization, especially and. CONCLUSIONS: Absence of adequate salivary flow in intubated intensive care unit patients causes severe xerostomia, which may contribute to the development of mucositis and oropharyngeal colonization with Gram-negative bacteria.

Adult↗