Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “pathogen isolation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 829 records · Page 46Linked to original sources
PubMed2005

[Microorganisms isolated from outpatient urine samples and antimicrobial susceptibility over a 12-year period].

This study aimed to determine the prevalence of microorganisms isolated from urine samples from outpatients and the resistance of the pathogens isolated to antimicrobial agents used in the province of Cordoba, Spain, which has a Health Area of approximately 776,000 inhabitants. It was a retrospective descriptive study covering a 12-year period (1992-2003). All samples were sent from primary care to the microbiology laboratory. The laboratory techniques and criteria for evaluation were the same in all cases. Escherichia coli was the most frequently isolated of the Gram-negative bacteria (64%), while Enterococcus faecalis was the most frequently isolated of the Gram-positive bacteria (6.9%). A decrease in susceptibility of the isolates to the most empirically used antimicrobial drugs was observed.

Drug Resistance, Bacterial↗
PubMed2003

Pathogenicity of three isolates of porcine respiratory coronavirus in the USA.

The pathogenicity of three isolates of porcine respiratory coronavirus (AR310, LEPP and 1894) from the USA was assessed in specific pathogen-free pigs. Pigs inoculated with 1894 developed mild respiratory disease and pigs inoculated with AR310 and LEPP developed moderate respiratory disease from four to 10 days after they were inoculated, but all the pigs recovered fully by 14 days after inoculation. Gross and microscopic examination revealed mild (1894) to moderate (AR310 and LEPP) multifocal bronchointerstitial pneumonia from four to 10 days after inoculation. The lesions were characterised by necrotising bronchiolitis, septal infiltration with mononuclear cells, and a mixed alveolar exudate. No clinical signs or microscopic lesions were observed in control pigs that had not been inoculated.

Animals↗
PubMed1994

[An evaluation of pathogens in patients with bronchopulmonary infection by transtracheal aspiration: December 1978-March 1993].

We performed transtracheal aspiration (TTA) in 1165 patients, who were suspected to have bronchopulmonary infection, from December 1978 to March 1993. We isolated pathogens from TTA in 806 patients (69.2%). We isolated H. influenzae (62 cases), S. pneumoniae (39 cases) and M. catarrhalis (24 cases) in patients with acute bronchitis, S. pneumoniae (65 cases), alpha-Streptococcus sp. (52 cases), H. influenzae (32 cases) and S. aureus (29 cases) in patients with pneumonia or lung abscess and H. influenzae (174 cases), S. pneumoniae (84 cases), P. aeruginosa (81 cases) and M. catarrhalis (42 cases) in patients with chronic lower respiratory tract infection. Anaerobic bacteria isolated from TTA included Peptostreptococcus sp. (19 cases), Bacteroides sp. (19 cases) and others. Mycoplasma pneumoniae was isolated from TTA in 8 patients with pneumonia without other organisms. Virus isolated from TTA included Rhinovirus (6 cases) and others. These results suggest that various pathogens affect the pathogenesis of bronchopulmonary infection. Therefore, we must diagnose the bronchopulmonary infection by the correct methods such as TTA.

Adult↗
PubMed1981

Hemagglutination of human type O erythrocytes, hemolysin production, and serogrouping of Escherichia coli isolates from patients with acute pyelonephritis, cystitis, and asymptomatic bacteriuria.

The purpose of this investigation was to study potential virulence factors associated with Escherichia coli urinary pathogens isolated from patients with urinary tract infection. These factors were compared with characteristics of normal-flora E. coli isolated from stool specimens of healthy individuals without a history of urinary tract infection. The potential virulence factor focused on in this study was hemagglutination (HA) of human type O erythrocytes by E. coli urinary pathogens. A total of 265 strains of E. coli isolated from patients with urinary tract infections were tested for their ability to hemagglutinate human type O erythrocytes; of these, 148 (56%) were HA positive. Only 6 of 36 fecal E. coli strains (17%) isolated from healthy controls were HA positive. This significant association of the presence of hemagglutinin on E. coli that causes urinary tract infections indicates the likelihood that HA is a marker of virulence. Only 12% (5 of 43) of Proteus mirabilis and 3% (3 of 104) of Klebsiella pneumoniae urinary isolates were HA positive. There was a trend for HA-positive E. coli to be isolated from patients with kidney infections and positive tests for antibody-coated bacteria rather than bladder infections and negative tests for antibody-coated bacteria, although the difference was not statistically significant. There was a significant correlation (P < 0.025) between hemolysin production and HA; 67% (69 of 103) of the isolates that produced hemolysin also hemagglutinated human type O erythrocytes. There was no significant correlation between HA and motility, although there was a trend for flagellated organisms to be non-hemagglutinators. There was a marked correlation between the presence of hemagglutinin and the serogroup of the E. coli isolate; serogroups O4, O7, and O50 were almost always HA positive (57 of 63; 90%). In contrast, serogroups O8 and O25 were rarely HA positive (2 of 30; 7%).

ABO Blood-Group System↗
PubMed1987

Salmonella serotypes and incidence of multiply-resistant Salmonellae isolated from diarrhoeal patients in Hong Kong from 1973-82.

Salmonella was the most frequent bacterial pathogen isolated from patients with acute diarrhoea in Hong Kong. In Queen Mary Hospital, the major hospital on Hong Kong Island, 94.7% of salmonellae isolated from faecal specimens from patients during the period 1973-82 belonged to the gastroenteric group, while 5.3% belonged to the enteric fever group. Amongst the gastroenteric group, 68 salmonella serotypes were identified, with Salmonella derby, S. typhimurium and S. anatum being the predominant ones. Three outbreaks caused by S. johannesburg, S. worthington and S. wandsworth were detected. Of S. typhimurium, 61.6% were resistant to multiple antibiotics and belonged to four major phage types: 193, 22, 138 and U288. The majority (96.8%) of S. johannesburg strains which caused a widespread epidemic were multiply-resistant. Multiple antibiotic resistance was rarely observed in most other gastroenteric salmonellae. S. typhi was the commonest of the enteric fever group isolated from the blood of patients. Nineteen phage types were identified; E1 being the commonest (18.5%) while 21% were nontypable. Many of these isolated were resistant to streptomycin or sulphadiazine, but none were resistant to ampicillin, chloramphenicol or trimethoprim.

Bacteriophage Typing↗
PubMed2004

Accuracy and appropriateness of antimicrobial susceptibility test reporting for bacteria isolated from blood cultures.

Accurate antimicrobial susceptibility testing (AST) and appropriate reporting of AST results for pathogens isolated from blood cultures are critical functions of the microbiology laboratory. We studied AST performance and reporting from positive blood cultures at hospital microbiology laboratories in Iowa. One hundred sixteen episodes of bacteremia from 14 participating hospitals were examined. We detected AST or identification errors for 18 episodes (16%) and judged reporting of AST results to be inappropriate for 38 episodes (33%). Further study is necessary to determine the impact of testing errors and suboptimal reporting of results on the management of bloodstream infection.

Bacteremia↗
PubMed1993

A non-comparative, multicentre study of cefepime in the treatment of serious bacterial infections.

Multi-resistant strains of Gram-negative bacteria are rapidly emerging as a frequent cause of serious bacterial infection in the hospital environment. Effective treatment must include an antibiotic with activity against these organisms. In an open multicentre study, cefepime was evaluated as empirical therapy in 156 hospitalized patients (mean age 57 years) with serious infection of the urinary tract (n = 43), lower respiratory tract (n = 101) and skin and soft tissue (n = 12). In 18 patients, septicaemia/bacteraemia was also diagnosed. Cefepime, 2 g bd, was administered for a maximum of 16 days (mean 8). Of 98 pathogens isolated, 75 were Gram-negative and 23 were Gram-positive species. Ninety-four of the pathogens were susceptible to cefepime, including multi-resistant isolates such as Pseudomonas aeruginosa and Enterobacter cloacae. The overall clinical cure rate, excluding septicaemia/bacteraemia, was 92% (94/102); the corresponding bacterial eradication rate was 95% (52/55). In patients with septicaemia/bacteraemia, the clinical cure rate was 87% (13/15) despite eradication of 100% (11/11) of the assessable pathogens. Cefepime was well-tolerated, although 14 (9%) patients experienced local intolerance at the infusion site. Other drug-related adverse events were reported in six (4%) patients and included diarrhoea, pruritus, rash and urticaria. Cefepime is safe and effective as empirical treatment for serious infections commonly found in the hospital setting. Clinical cure and bacterial eradication can be achieved with a convenient bd dosing schedule.

Adolescent↗
PubMedDate not supplied

Studies of bacterial, rotaviral and Cryptosporidium etiology of acute diarrheal diseases in hospitalized children.

657 hospitalized children with acute diarrheal disease were studied for bacterial and rotaviral etiology. Cryptosporidium presence was followed in 123 children. Intestinal pathogens were detected in 195 (29.6%) cases: 132 (20.3%) enterobacteria, 47 (7.1%) rotaviruses, 4 (3.2%) Cryptosporidium sp. and 12 (1.8%) combined infections. Among enterobacteria, E. coli was the most frequent (10% cases) with enteropathogenic (EPEC), enterotoxigenic (ETEC), enterohemorrhagic (EHEC) and enteroinvasive (EIEC) groups. Other isolated pathogens were Salmonella--21 (3.1%), C. jejuni/coli--13 (1.9%), Shigella--3 (0.9%), Y. enterocolitica O3--1 (0.1%). Among opportunistic pathogenic enterobacteria, the following were isolated: Kl. pneumoniae--24 (3.7%), Enterobacter species--4 (0.6%), Providencia alcalifaciens--1 (0.1%). Aeromonas hydrophila was isolated in 1 child. Combined infections were detected in 12 children: 10--enterobacteria + rotaviruses associations and 2--pathogenic enterobacteria associations.

Acute Disease↗
PubMed1992

Diversity among Streptomyces Strains Causing Potato Scab.

Eighty Streptomyces isolates, including 35 potato scab-inducing strains and 12 reference strains of Streptomyces scabies, were physiologically characterized by a total of 329 miniaturized tests. Overall similarities of all strains were determined by numerical taxonomy, with the unweighted average linkage (UPGMA) algorithm and simple matching (S(sm)) and Jaccard (S(j)) coefficients used as measures for similarity. Three cluster groups (A to C) were defined at a similarity level of 80.1% (S(sm)); these groups contained 14 clusters and 24 unclustered strains defined at a similarity level of 86.5% (S(sm)). Cluster group A contained strains phenotypically related to S. griseus or S. exfoliatus, whereas cluster group B contained strains which were phenotypically related to S. violaceus or S. rochei. The majority of the pathogenic isolates and reference strains were assigned to S. violaceus (57%) and S. griseus (22%). A DNA probe derived from the rRNA operon of S. coelicolor IMET 40271 was used to detect restriction fragment length polymorphisms (RELPs) among 40 pathogenic and nonpathogenic Streptomyces isolates. Southern blots revealed a high degree of diversity among the pathogenic strains tested. No significant correlation between numerical classification and RFLP grouping of Streptomyces strains could be revealed. The results obtained suggest that RFLP data are of minor importance in classification of Streptomyces species and that genes for pathogenicity determinants are spread among different Streptomyces species by mobilizable elements.

Journal Article↗
PubMedDate not supplied

Comparative pathogenicity of trichomonas vaginalis isolated from symptomatic & asymptomatic cases.

Pathogenicity of 19 isolates of T.vaginalis obtained from vaginal specimens were studied in the murine model by intraperitoneal route. Sixteen isolates were recovered from the females with various clinical conditions and 3 isolates were from normal healthy females. Pathogenicity level of these isolates were studied by inoculating 5 mice per isolates through intraperitoneal route and the animals were sacrificed on tenth day post-inoculation. In general, all the isolates recovered produced infection in mice. On comparison with the reference strain obtained from Hoechst India Ltd., seven isolates recovered from symptomatic cases and one strain from healthy females produced severe infection in mice. Though variation in pathogenicity level was observed among the isolates, a definite correlation between clinical picture in natural host and pathogenicity in mice was not observed.

Animals↗
PubMed1991

Infection of Waldeyer's ring: value of pernasal retropharyngeal swabs.

The value of pernasal retropharyngeal swabs in chronic adenoid and tonsillar disease was assessed in a prospective study involving 52 patients. Prior to adenoidectomy (34 patients) or adenotonsillectomy (17 patients), pernasal and tonsillar swabs were taken and the culture compared to the bacteriology profile obtained in the adenoid and tonsil tissue following surgery. The pernasal swab correctly identified 76% of pathogens isolated in the adenoid tissue. In addition, pernasal swabs forecast the presence of pathogens in 64% of core tonsil specimens, compared to an accuracy of 38% when superficial tonsil swabs were compared to the microbes in the deep tonsil. H. influenzae was the predominant organism isolated in all cultures. Our results clearly demonstrate that pernasal swabs give a representative picture of the adenoid bacterial content. Pernasal swabs are also superior to superficial tonsil swabs in indicating the deep tonsillar organisms.

Adenoidectomy↗
PubMed2002

Cryptosporidium virulence determinants--are we there yet?

Exposure to Cryptosporidium parvum in healthy individuals results in transient infection that may be asymptomatic or can result in self-limited diarrhoea. In contrast, acquired immune deficiency syndrome patients with cryptosporidiosis can experience severe manifestations of disease. Volunteer studies have demonstrated that as few as 10 oocysts can cause infection in otherwise healthy adults and that isolates from geographically diverse regions differ in infectivity and, perhaps, virulence. Variability in isolate pathogenicity and infectivity has also been seen in bovine and murine models, respectively. Furthermore, isolate specific differences in protein composition and in host immunoreactivity have been observed. The molecular basis for differences in pathogenicity is not understood. Determining which factors are responsible for host selectivity and for the initiation, establishment, and perpetuation of infection with Cryptosporidium is key to rational drug design and vaccine development. To date, no specific virulence factors have been unequivocally shown to individually cause direct or indirect damage to host tissues nor have mutant strains been produced that could prove that particular deletions result in less virulent strains. Nevertheless, a number of candidate molecules have been identified by immunological and molecular methods. Here, we review the salient characteristics of some of these putative virulence determinants, including molecules that are involved in adhesion, protein degradation and the modulation of the host responses.

Adult↗
PubMedDate not supplied

Epidemiology of beta-lactamases in Africa: correlation with resistance to beta-lactam antibiotics.

In 45 centers from eight African countries, 2,888 bacterial isolates were collected from patients with community-acquired infections. Isolated pathogens included Staphylococcus aureus (29%), Escherichia coli (20%), Neisseria gonorrhoeae (6%), Proteus species (6%), Klebsiella species (6%), Klebsiella pneumoniae (4%), and Staphylococcus epidermidis (4%). An overall sensitivity of 16.2% was shown to penicillin G (number of isolates tested = 2,467), 31.8% to ampicillin (2,687), 45% to amoxicillin (1,959), and 84.9% to cefuroxime (2,888). Beta-lactamase presence was measured by a chromogenic method. Beta-lactamase was found in 75% of all pathogens tested, including 69.5% of gram-negative and 83.3% of gram-positive pathogens; 73% of E coli isolates, 76% of N gonorrhoeae, 75% of Klebsiella species, and 84% of S aureus were beta-lactamase positive. Beta-lactamase presence was associated with bacterial resistance for penicillin G, ampicillin, and amoxicillin, but not cefuroxime, whose sensitivity remained high. The higher resistance rates and beta-lactamase prevalence in Africa suggest the need for national antibiotic prescribing policies and surveillance schemes and replacement of relatively ineffective penicillins with newer agents such as cefuroxime.

Africa↗
PubMed1984

Pathogenicity of newly isolated coxsackievirus B4 for mouse pancreas.

Coxsackievirus B4 fresh isolates from patients with upper respiratory illness and aseptic meningitis were studied for their pathogenicity in the pancreas of SJL/J mice. Out of 12 virus isolates, 7 induced hypoglycaemia in mice 2 to 4 days after virus inoculation. All 3 isolates from faeces of patients induced hypoglycaemia in contrast to 3 viruses isolated from the cerebrospinal fluid which did not. Six isolates from throat swabs were either pathogenic (4 isolates) or non-pathogenic (2 isolates). It is concluded that at least two biologically distinct coxsackieviruses B4 prevail among humans.

Animals↗
PubMed1987

Azlocillin, cephalothin, and tobramycin therapy in febrile solid tumor patients with chemotherapy-induced leukopenia.

Although the semisynthetic broad-spectrum acylureido-penicillin, azlocillin has been demonstrated to have significant antibiotic activity in leukemic patients, its role in combination therapy of febrile granulocytopenic patients with chemotherapy-treated solid tumors has not been clearly delineated. Thirty-five solid tumor patients with chemotherapy-induced absolute granulocytopenia (less than 1000 granulocytes/ml) associated with fever (greater than 38.3 degrees C) were treated on a prospective study with a combination of azlocillin 4 g intravenously (IV) every 6 hours, cephalothin 2 g IV every 6 hours, and tobramycin 80 to 100 mg IV every 8 to 12 hours. Prior chemotherapy included doxorubicin combinations in 18 patients and other combinations in 17 patients. Granulocyte counts preantibiotic therapy were greater than 100 granulocyte/ml in 14 patients, 100 to 499 in nine patients, and 500 to 1000 in 12 patients. Granulocyte nadirs were less than 100 in 20 patients, 100 to 499 in nine patients, and 500 to 1000 in six patients. Times for granulocytes to rise towards normal were 1 to 3 days in eight patients, 4 to 6 days in 18 patients, and 7 or more days in nine patients. Tobramycin levels were primarily in the peak range of 3 to 6 micrograms/ml and trough range of 0 to 1.9 micrograms/ml. The site and pathogen were identified in nine patients, the infection site clinically documented without isolated pathogen in three patients, and no site or pathogen identified in 23 patients. Of the 35 patients, 34 had good responses to the antibiotic combination (complete disappearance of fever and other evidence of infection). Serum creatinine rose 0.4 to 0.6 mg/dl in nine patients, 0.7 to 1.5 in four patients, and 1.5 in one patient (obstructive uropathy). The only other noted antibiotic-related side effect was hypokalemia. This antibiotic combination had little toxicity with marked efficacy.

Adult↗
PubMed2006

Association of human metapneumovirus with acute otitis media.

OBJECTIVE: Human metapneumovirus (hMPV) is a recently described paramyxovirus that has been associated with acute upper and lower respiratory infection (LRI) in infants and children worldwide. We previously observed that one-third of the children with hMPV-associated LRI had been diagnosed with a concomitant acute otitis media (AOM). In the current study, we sought to investigate an association between hMPV and children presenting with AOM as a primary diagnosis. METHODS: We used realtime RT-PCR for hMPV to retrospectively test 144 paired nasal wash (NW) and middle ear fluid (MEF) specimens that had been prospectively collected from children with AOM during a 3-year period from 1990-1992. RNA was extracted from archived, frozen samples and realtime RT-PCR for hMPV was performed. RESULTS: We detected hMPV in 8/144 (6%) NW and 1/144 MEF. Several of the children still tested positive for hMPV in NW 3 days later, showing persistent virus shedding. All were detected from November-May and six had bacterial co-pathogens. Two of the eight (25%) hMPV-infected children had no bacterial pathogen isolated, suggesting that hMPV may be associated with AOM as a sole pathogen. CONCLUSIONS: These data show that hMPV is associated with a proportion of AOM and thus has additional morbidity and healthcare impact related to these illnesses.

Acute Disease↗
PubMed2005

The effect of hygienic treatment on the microbial flora of biowaste at biogas plants.

In Sweden, full-scale, commercial biogas plants (BGP), which process low-risk animal waste, operate a separate pre-pasteurisation at 70 degrees C for 60 min as required by EEC regulation 1774/2002. The purpose of this study was to establish if, during pasteurisation and further processing and handling in full-scale BGPs, pathogens in biowaste could be sufficiently reduced to allow its use on arable land. Four BGPs were sampled on six occasions during 1 year. Sampling was performed from six locations during biogas production. The samples being analysed quantitatively to detect indicator bacteria (Escherichia coli, Enterococcus spp. and coliforms) and spore-forming bacteria (Clostridium spp. and Bacillus spp.) and qualitatively for bacterial pathogens (salmonella, listeria, campylobacter and VTEC O157). Salmonella was the most frequently isolated pathogen before pasteurisation In general, the treatment adequatly reduced both indicator and pathogenic bacteria. Spore-forming bacteria were not reduced. However, recontamination and regrowth of bacteria in biowaste was frequently noted after pasteurisation and digestion.

Animal Husbandry↗