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At least 487 records · Page 27Linked to original sources
PubMed2000

Antimicrobial activity of home disinfectants and natural products against potential human pathogens.

OBJECTIVE: To assess the efficacy of both natural products (vinegar, baking soda) and common commercial disinfectants (Vesphene IIse, TBQ, Clorox, Lysol Disinfectant Spray, Lysol Antibacterial Kitchen Cleaner, Mr. Clean Ultra, ethanol) designed for home or institutional use against potential human pathogens, including selected antibiotic-resistant bacteria. DESIGN: A quantitative suspension test was used to assess the efficacy of selected disinfectants following exposure times of 30 seconds and 5 minutes. Activity was assessed against Staphylococcus aureus, Salmonella choleraesuis, Escherichia coli O157:H7, and Pseudomonas aeruginosa. Selected disinfectants were also tested against poliovirus, vancomycin-susceptible and -resistant Enterococcus species, and methicillin-susceptible and -resistant S. aureus. RESULTS: The following compounds demonstrated excellent antimicrobial activity (>5.6-8.2 log10 reduction) at both exposure times: TBQ, Vesphene, Clorox, ethanol, and Lysol Antibacterial Kitchen Cleaner. Mr. Clean eliminated 4 to >6 logs10 and Lysol Disinfectant approximately 4 logs10 of pathogenic microorganisms at both exposure times. Vinegar eliminated <3 logs10 of S. aureus and E. coli, and baking soda <3 logs10 of all test pathogens. All tested chemical disinfectants completely inactivated both antibiotic-resistant and -susceptible bacteria at both exposure times. Only two disinfectants, Clorox and Lysol, demonstrated excellent activity (>3 log10 reduction) against poliovirus. CONCLUSIONS: A variety of commercial household disinfectants were highly effective against potential bacterial pathogens. The natural products were less effective than commercial household disinfectants. Only Clorox and Lysol disinfectant were effective against poliovirus.

Disinfectants↗
PubMedDate not supplied

Vaginal flora of first time urban family planning attendants in Accra, Ghana.

OBJECTIVE: To determine the vaginal flora of first time urban Family Planning clients at Korle-Bu Teaching Hospital and to assess its implications for the contraceptive choices made. DESIGN: A cross sectional study. METHODS: A standardized questionnaire surveying the sociodemographic characteristics and the choice of Family Planning method was administered to 100 clients at the Korle Bu Teaching Hospital between March and September 2001. High vaginal and endocervical swabs were also taken during the inspection of the vagina and cervix using a sterile bivalve speculum. The specimens were transported in Amies transport medium to the Microbiology laboratory for processing. RESULTS: The age range of the clients was 19-48 years with a modal age of 28 years. Ninety-six percent of them were married while 86% lived in urban slums. Sixty-three percent were sure of their last menstrual period. Potential pathogens were isolated from culture in 56% of the clients. Organisms causing bacterial vaginosis were the most prevalent in their genital tract. The intrauterine contraceptive device (IUCD) was the most common Family Planning method chosen, followed by the Norplant and the Depo-Provera injections. Potential pathogens were isolated from culture in 50% of those who chose the IUCD. CONCLUSION: Potential pathogens were isolated from culture in 56% of these first-time clients and organisms causing bacterial vaginosis were the most prevalent in the genital tract. It is suggested that Family Planning clients who screened positive for potential pathogens and opt for the IUCD should be considered for prophylactic antibiotics at insertion.

Adult↗
PubMed1975

Secondary ocular bacterial infection in hypovitaminosis a xerophthalmia.

Extraocular bacterial culture was performed in 100 patients with hypovitaminosis A xerophthalmia. There was corneal ulceration in 29 cases and corneal perforation in 22 cases. Eighty-six percent of the patients harbored frankly pathogenic bacteria (46 patients) and potentially pathogenic bacteria (40 patients). All but two patients with either cornal ulceration or perforation harbored potentially pathogenic or frankly pathogenic bacteria. Pseudomonas aeruginosa, Diplococcus pneumoniae, and Moraxella species were isolated in 37% (19 patients) of cases with corneal ulceration and perforation. I cultured P. aeruginosa from 36% (eight patients) of cases with corneal perforation. The many ocular secondary bacterial infections in the early stages of xerophthalmia seem to suggest that bacterial action plays a major role in causing the corneal ulceration and perforation in hypovitaminosis A xerophthalmia.

Adolescent↗
PubMed1996

Nucleic Acid-based Pathogen Discovery Techniques: Potential Application to Xenozoonoses.

Pathogen discovery techniques based on detection and characterization of microbial nucleic acids have potential application to the field of xenotransplantation. Techniques such as broad-range polymerase chain reaction and representational difference analysis may make it possible to define the zoonotic flora present within donor animal species to an extent never before possible. This review describes the current practice of these techniques, with an emphasis on the use of these methods for identifying zoonotic agents. Identification of potential pathogens in colony-reared donors may lead to isolation and selective breeding practices that could ultimately eliminate these agents from the donor pool.

Journal Article↗
PubMed2006

Influence of the gastrointestinal microbiota on development of the immune system in young animals.

The gastrointestinal tract (GIT) of adult mammals is colonized by a complex and dynamic community of microorganisms. Most protection against potential pathogens occurs via a mucosal immune system involving mechanisms of innate immunity as well as a secondary lymphoid organ, the gut-associated lymphoid tissue (GALT). However, the bacterial community also supports its host against invasion by potential pathogens, by a mechanism called 'colonization resistance'. Young animals need time to develop both a complex bacterial community and their immature GIT immune system, and until such developments have taken place, they are vulnerable to the presence of potential pathogens in their GIT. Initial protection against invading pathogens is provided by milk and colostrum, which contain antibodies and other bioactive components. At weaning, with the introduction of solid food and deprivation of the mother's milk, the young must also cope with a rapidly changing microbiota. The colonizing microbiota not only provides colonization resistance to potentially pathogenic bacteria. It also has a major role in the development of the intestinal immune system, both in terms of GALT development and mucosal immunity, and the induction of oral tolerance. Studies using gnotobiotic animal models have revealed that the presence of even limited numbers of the indigenous microbiota may influence the GIT immune system. Regulation of the composition of the GIT microbiota, e.g. by the use of pre- and probiotics, offers the possibility to influence the development of mucosal, and also systemic immunity.

Animals↗
PubMed2005

Antimicrobial susceptibilities of potential bacterial pathogens in adults with acute respiratory tract infections Prospective Epidemiological Network Investigating Community-acquired Infection SurveiLLance In Nagasaki (PENICILLIN) Study.

The prevalence and the antimicrobial susceptibilities of bacterial pathogens in acute upper respiratory tract infections (AURTIs) is not clear. We conducted a prospective community-based multicenter study in 45 centers across Nagasaki, Japan, between December 2001 and April 2002. We examined the nasopharyngeal or throat isolates in 930 adult outpatients with AURTIs. Potential bacterial pathogens, including Streptococcus pyogenes (from 6.8% patients), S. pneumoniae (5.3%), S. milleri group (2.0%), Staphylococcus aureus (26.0%), Moraxella catarrhalis (7.4%), Haemophilus influenzae (17.6%), and Klebsiella pneumoniae (1.2%), were isolated from 51.8% of the patients. Penicillin nonsusceptible phenotype accounted for 44.9% of S. pneumoniae isolates. Among Staphylococcus aureus isolates, 9.1% were methicillin-resistant. In H. influenzae isolates, 6.7% produced beta-lactamase and 23.2% were beta-lactamase-negative ampicillin-resistant. The results indicated that the potential bacterial pathogens were detected in the remarkable population of the adults with AURTIs and the current antimicrobial susceptibilities of such pathogens.

Acute Disease↗
PubMed1995

Porcine reproductive and respiratory syndrome: NEB-1 PRRSV infection did not potentiate bacterial pathogens.

A 2-phase study was conducted to evaluate the ability of the NEB-1 strain of porcine reproductive and respiratory syndrome virus (PRRSV) to potentiate common bacterial pathogens of swine. In phase I, 25 of 50 4-5-week-old specific-pathogen-free (SPF) pigs were exposed to NEB-1 PRRSV (day 0). Seven days after virus inoculation, 8 groups received 1 of 4 bacterial pathogens: Haemophilus parasuis, Streptococcus suis, Salmonella cholerasuis, and Pasteurella multocida. The ability of NEB-1 PRRSV to produce clinical disease, viremia, neutralizing antibody, gross and microscopic lesions and to potentiate bacterial pathogens was assessed. Response to NEB-1 PRRSV was similar among inoculated pigs; prolonged hyperthermia, lethargy, mild to moderate dyspnea, and cutaneous erythema were consistent clinical signs. No clinical differences were observed in groups after bacterial challenge. Virus was isolated from serum at weekly intervals through the end of the study, and all PRRSV-inoculated pigs had seroconverted by study termination. Two of 5 pigs died in non-PRRSV-inoculated groups challenged with H. parasuis and Streptococcus suis. Mortality in PRRSV-infected pigs was limited to 1 of 5 pigs from the Salmonella cholerasuis-challenged group. Gross lesions were seen in pigs dying after inoculation in H. parasuis- and Streptococcus suis-inoculated groups, in Salmonella cholerasuis- and P. multocida-challenged pigs, and in 1 non-PRRSV-inoculated control pig. Microscopic lesions consisted of mild to moderate proliferative interstitial pneumonia, nonsuppurative myocarditis, lymphoid hyperplasia, and nonsuppurative encephalitis in PRRSV-inoculated pigs. Findings in phase I indicated that NEB-1 PRRSV does not potentiate bacterial disease while inducing consistent clinical signs, viremia, seroconversion, and microscopic lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2005

Biofilms in an urban water distribution system: measurement of biofilm biomass, pathogens and pathogen persistence within the Greater Stockholm Area, Sweden.

Distribution pipe biofilms can provide sites for the concentration of a wide range of microbial pathogens, thereby acting as a potential source of continual microbial exposure and furthermore can affect the aesthetic quality of water. In a joint project between Stockholm Water, the MISTRA "Sustainable Urban Water" program, the Swedish Institute for Infectious Disease Control and the Royal Technical University, Stockholm, the aim of the current study was to investigate biofilms formed in an urban water distribution system, and quantify the impact of such biofilms on potential pathogen accumulation and persistence within the Greater Stockholm Area, Sweden. When used for primary disinfection, ultra-violet (UV) treatment had no measurable influence on biofilm formation within the distribution system when compared to conventional chlorination. Biofilms produced within a model pilot-plant were found to be representative to those that had formed within the larger municipal water distribution system, demonstrating the applicability of the novel pilot-plant for future studies. Polystyrene microspheres (1.0 microm) and Salmonella bacteriophages demonstrated their ability to accumulate and persist within the model pilot-plant system, where the means of primary disinfection (UV-treatment, chlorination) had no influence on such phenomena. With the exception of aeromonads, potential pathogens and faecal indicators could not be detected within biofilms from the Stockholm water distribution system. Results from this investigation may provide information for water treatment and distribution management strategies, and fill key data gaps that presently hinder the refinement of microbial risk models.

Aeromonadaceae↗
PubMed2005

A cohort study of Yersinia infection in goats.

OBJECTIVE: To determine the temporal pattern of Yersinia infections in three goat flocks and examine the influence of management and seasonal factors on the incidence of those infections over a 1-year period. METHODS: A longitudinal study involving monthly culture of faeces for Yersinia spp. from age groups of randomly selected goats on three farms in the Manawatu region of New Zealand. RESULTS: The incidence of excretion of potentially pathogenic Yersinia (Yersinia pseudotuberculosis and Y enterocolitica biotypes 2, 3 and 5) peaked in winter and fell in summer. In contrast, environmental Yersinia (Y enterocolitica biotype 1A, Y frederiksenii, Y intermedia and Y rohdei) showed no clear pattern of seasonal variation. Pathogenic Yersinia were more prevalent in young animals than in adults, while environmental Yersinia were more prevalent in adults. The same type was isolated from the same animal in two or more successive months in about 20 to 25% of cases, and in the remaining cases there was a gap of at least one month between successive isolations, with many animals yielding a particular type on only a single occasion. A notable difference was that with the potentially pathogenic types, no animal had more than one period of time when it was found to be excreting a particular type, suggesting that immunity develops following exposure. In contrast, it was common for environmental types to be isolated from the same animal throughout the study period. Two goats were suspected to have developed clinical yersiniosis but all remaining infected animals showed no clinical signs of infection. CONCLUSIONS: Asymptomatic Yersinia carriage was common in goats in New Zealand, with a clear seasonal and age group pattern of infection with potentially pathogenic types. There was evidence that immunity developed to potentially pathogenic types. This is the first time that Y rohdei has been isolated from goats.

Age Factors↗
PubMed1988

Does gastric acid protect the preterm infant from bacteria in unheated human milk?

Although preterm mother's milk has greater nutritional and anti-infective properties than donor milk, it may be highly contaminated with bacteria. We therefore asked three questions: what is the fate of these bacteria in the preterm infant's stomach, is gastric pH important, and what factors affect gastric pH? pH, colony count and bacterial identification were performed on the milk and on serial gastric aspirates in 20 preterm infants on 25 occasions. Seventeen milk samples grew bacteria, five potentially pathogenic and 12 non-pathogenic. Twelve of 25 prefeeding gastric samples were sterile, but following the feeding all the samples grew non-pathogenic bacteria and 70% grew potential pathogens. With time pH decreased and by 2-h samples with pH less than 3.5 had no bacterial growth; Candida albicans still flourished in a low pH (mean 2.8). We concluded that a low gastric pH may be more important than the bacterial count of the milk. In a second study, 91 serial gastric pH measurements were made on 12 preterm infants. pH tended to decrease with increasing age and was significantly lower in infants fed exclusively human milk (2.7 vs. 3.6; human milk versus formula P less than 0.02) We speculate that human milk may influence gastric acid production and thus protect the preterm infant from bacteria in the milk.

Gastric Acid↗
PubMedDate not supplied

[Effects of adenoidectomy and tonsillectomy on the bacterial flora of the nose and oropharynx].

The oropharyngeal and nasopharyngeal microbial flora was studied in 55 children with recurrent tonsillitis and in 85 with chronic adenoiditis. Swabs were made of both regions one day before surgical removal and on postoperative days 10 and 30, swabs were cultured on suitable media and processed for identification and quantitative estimation. Most of the potentially pathogenic species exhibited beta-lactamase production. After adenoidectomy or tonsillectomy this potentially pathogenic flora showed a quantitative decrease in the number identified and in their growth rate. In contrast, Bacteria considered part of the normal flora showed an increase in their were isolated more frequently although a quantitative decrease was observed in some instances. These findings suggest that adenoidectomy and tonsillectomy result in evident modifications in potentially pathogenic flora in these sites as a result of replacement by the normal flora. There are microbiological findings that justify surgical procedures in case of failure of antibiotic treatment.

Adenoidectomy↗
PubMed1998

Nasopharyngeal bacteria found on blood agar plates from healthy children in Greenland.

We have systematically studied the aerobic nasopharyngeal bacteria isolated from swabs by unselective subculturing on 5% horse blood agar and chocolate agar in 70 healthy children aged 0-1, 3-5 and 8 years in Nuuk and Sisimiut, Greenland. The purpose was to provide a basis for a better understanding of the infectious pathology and blind antibiotic treatment against potential pathogens thereby improving standard antimicrobial treatment of upper respiratory tract infections (URTI) and otitis media (OM) among children in Greenland. The study serves also as a baseline for future microbiological and immunological research projects. The children were clinically examined for any infectious diseases and a medical history was obtained which allowed for selection of children without a history of severe clinical infection. Nasopharyngeal swabs obtained via the oral route were instantly spread on 5% blood agar and chocolate agar culture plates and incubated aerobically. Subsequently, potentially pathogenic as well as non-pathogenic bacteria were identified by conventional methods. Healthy children in Greenland carry grossly the same aerobic bacterial flora as children in other parts of the world but potentially pathogenic bacteria were found in very high frequency (94%). Staphylococcus aureus, Streptococcus pneumoniae and Moraxella catarrhalis were found in higher frequencies in the youngest children. Haemophilus influenzae non-b was found in high frequencies in all age groups (67-76%). H. influenzae type b was carried by 11.4%. Group A streptococci were found more frequently in older children and in children from Sisimiut. Of M. catarrhalis strains 88% produced beta-lactamase. Neisseria meningitidis, Mycoplasma pneumoniae and chlamydiae were not detected at all. The high carrier frequency of potentially pathogenic bacteria in healthy children in Greenland may be related to the high frequency of URTI's and episodes of OM among children in Greenland.

Bacteria, Aerobic↗
PubMedDate not supplied

Long-term prophylaxis of infection by selective decontamination in leukopenia and in mechanical ventilation.

The autochthonous anaerobic bacterial flora in the mucosal layer of the gastrointestinal tract limits colonization by aerobic potential pathogens. This effect is called colonization resistance. Colonization of the digestive tract by potentially pathogenic microorganisms precedes infection in patients with leukopenia and in cases of mechanical ventilation and can be prevented by long-term administration of antimicrobial agents that spare the autochthonous anaerobic bacterial flora of the mucous membranes, a concept known as selective decontamination. Antimicrobial agents active against anaerobic flora reduce colonization resistance, permitting colonization by and overgrowth of potentially pathogenic microorganisms and possibly leading to infections with resistant microorganisms. A distinction can be made between antimicrobial agents that reduce colonization resistance and those that leave it intact by examining the effect of antimicrobial agents on aerobic intestinal flora of mice and humans.

Animals↗
PubMed1995

Changes to the ocular biota with time in extended- and daily-wear disposable contact lens use.

Gram-negative bacteria may play a role in the etiology of certain soft contact lens (SCL)-related diseases. Contact lens (CL) wear may modify the normal ocular biota, providing a more favorable environment for potential pathogens. This study reports temporal changes in ocular biota in daily-wear (DW) and extended-wear (EW) disposable SCL use in experienced and neophyte wearers. Lid margin and bulbar conjunctival biota were sampled prior to CL fitting in 26 previous DW SCL users, 18 previous EW SCL users, and 26 neophytes. Wearers were fitted with an etafilcon A CL in one eye and a polymacon CL in the fellow eye. Lenses were worn on a daily basis by the 26 previous DW SCL wearers and on an EW basis by the remaining 44 subjects. The ocular biota was further sampled after 1, 3, 6, 9, and 12 months of wear. The ocular biota consisted of coagulase-negative staphylococci, Corynebacterium spp., Micrococcus spp., and Propionibacterium spp. Potential pathogens were rarely isolated at baseline. No significant trend of increasing ocular colonization was shown for extended CL wear. Lid and conjunctival colonization increased with DW SCL use (P < 0.001), although this increase occurred for nonpathogenic species only. Fewer potential pathogens were isolated from DW SCL than from EW SCL users (P < 0.05). The lid margin consistently showed greater colonization than the conjunctiva and may be a source of potential pathogens during CL wear. Hydrogel CL wear appears to modify the ocular biota. An increased number of commensal organisms were present in DW SCL use. EW SCL use altered the spectrum of organisms isolated. These alterations may suppress the normal ocular defense mechanisms and may be relevant in the pathogenesis of CL-related disease.

Adult↗
PubMed1998

A case control study of potential enteric pathogens for calves raised in cow-calf herds.

A matched case control study was performed to describe the epidemiological features of potential enteric pathogens for calves reared in 53 cow-calf herds located in western Switzerland. A total of 106 diarrhoeic calves and 126 healthy control calves were collected, all calves were less than 4 months old. Faecal samples were analysed for presence of infectious agents related to calf diarrhoea including enterotoxigenic E. coli, Verotoxin producing E. coli (VTEC), Campylobacter sp., Yersinia sp., Salmonella sp., rotavirus, coronavirus, helminths and coccidian protozoa. Multivariate logistic models were used to analyse the relationship between presence of infection and onset of diarrhoea. The study provided evidence of significant associations between diarrhoea and infection with rotavirus, Campylobacter coli and the presence of Verotoxin in faecal samples. With the exception of Cryptosporidium parvum intestinal parasites including Strongylidae and Eimeria sp. were found to be less prevalent in cases than in controls. Control calves were significantly more frequently infected with Strongyloides papillosus than case animals.

Animals↗
PubMed2026

Dynamics of antibiotic resistance genes co-occurrence with pathogenic and non-pathogenic bacteria throughout wastewater treatment processes.

Wastewater treatment plants (WWTPs) are recognized hotspots for antibiotic resistance genes (ARGs) and pathogenic bacteria. Despite advancements in treatment technologies, the persistence of ARGs and pathogenic bacteria remains a concern. In this study, we analyzed the dynamic changes in ARGs and bacterial communities throughout the treatment processes within an anaerobic-anoxic-oxic (AAO) WWTP over one week by using HT-qPCR coupled with 16S rRNA gene amplicon sequencing. The connectedness index, based on network analysis, showed that the dynamics of ARGs and mobile genetic elements (MGEs) were more strongly associated with potentially pathogenic bacteria than with non-pathogenic bacteria, suggesting that ARG immigration and dissemination in the WWTP were likely driven by potentially pathogenic taxa. The AAO treatment significantly reduced ARGs in final effluent (EF) (&#x223c;64 %) and residual sludge (RS) (&#x223c;81 %); however, potential hosts of ARGs such as Comamonas testosteroni and Clostridioides difficile persisted with minimal changes in relative abundance and remained detectable in EF and RS. Notably, the abundance of ARGs was lower in RS than in EF, and source tracking analysis identified influent as the primary source of ARGs and potentially pathogenic taxa in EF, underscoring the greater health risks associated with effluent discharge.

Wastewater↗
PubMed1982

[Pathogenic mycobacteria].

It is well established that mycobacteria other than tubercle bacilli and M. leprae are important human pathogens. At least 15 species comprise all the presently known mycobacterial pathogens of man. Eleven species are potential pathogens because disease production often dependent on special factors of the human host. The comments include some characterization of the mycobacteria, especially of the potential pathogenic species. A summary of important nontuberculous mycobacterial diseases of man is presented.

Germany, East↗
PubMed2001

Quantitative culture of bronchoalveolar lavage fluid in community-acquired lower respiratory tract infections.

To evaluate the diagnostic value of quantitative bacterial culture of bronchoalveolar lavage (BAL) fluid obtained by fibreoptic bronchoscopy, 67 consecutive immunocompetent adult patients admitted to hospital with community-acquired lower respiratory tract infections from September 1997 to May 1998 were investigated. Results were compared to the findings in eight healthy control persons investigated in February 1998. There was no difference between study patients and control persons when quantitative culture of total cumulative bacterial findings or bacteria categorized as members of the oropharyngeal normal flora were compared. The culture of normal flora in bronchial washings probably reflects contamination of the lower airways with secretions from upper arways by the fibreoptic procedure itself, as fractionated sampling showed a 10-fold reduct on in quantitative culture results when a primary bronchial washing was compared to a secondary sampling from the same bronchus in the control group. Twenty-four (36%) of 67 patients were cultured as positive in the study group while all control persons were cultured as negative for bacteria categorized as potential pathogens. With a threshold value for positive culture of 10(4) cfu ml(-1) the specificity of lavage culture of potential pathogenic bacteria in relation to actual lower airway infection was 100%. Therefore, quantitative bacterial culture of potential pathogenic bacteria in BAL fluid is very specific but only positive in about one-third of unselected immunocompetent adult patients with a lower respiratory tract infection.

Adult↗