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PubMedDate not supplied

[In vitro susceptibility to a new antimicrobial agent (imipenem) of pathogens isolated from inpatients at various centers].

Imipenem is a beta lactam antibiotic, a highly potent new carbapenem with broad antibacterial spectrum. To test the "in vitro" efficacy of this antimicrobial agent in pathogens more frequent in several Medical Centers in Brazil, susceptibility testing with 10 mcg imipenem disks and, or corresponding MIC were carried out with 1231 recent isolates of 41 different bacterial species, obtained mainly from hospitalized patients in 5 different medical centers of the cities of S. Paulo, Rio de Janeiro and Salvador. Our preliminary results with this antibiotic, in final phases of clinical and laboratorial experimentation in this country, are very promissing with, 96.79% of susceptibility of test isolates to 10 mcg imipenem disks and corresponding MIC correlation of up to 4 micrograms/ml. (92.31%). Of the 9 bacterial species more frequently isolated totaling 1108 (82%) of the 1230 test isolates, disk susceptibility was 99% (E. coli), 93% (Pseudomonas aeruginosas), 87% (Staphylococcus aureus), 100% (Klebsiella pneumoniae), 98% (Klebsiella sp), 97% (Proteus mirabiles), 94% (Enterobacter sp), 100% (Streptococcus faecalis) with good MIC correlation (up to 8 mcg/ml) and 100% for the anaerobic species Bacteroides sp (MIC up to 4 micrograms/ml). "In vitro" efficacy to hospital pathogens with high frequency of resistance to most antibiotics as Pseudomonas aeruginosa and to anaerobes notably Bacteroides sp is emphasized.

Bacteria↗
PubMed2002

Bacterial pathogens isolated from cultured bullfrogs (Rana castesbeiana).

A commercial bullfrog (Rana castesbeiana) operation in south Georgia had multiple epizootics of systemic bacterial infections over a 3-year period, 1998-2000. A number of potential pathogens (Aeromonas hydrophila, Chryseobacterium (Flavobacterium) meningosepticum, Chryseobacterium (Flavobacterium) indolgenes, Edwardsiella tarda, Citrobacterfreundii, Pseudomonas spp., and (Streptococcus iniae) were isolated from various tissues. Clinically, frogs demonstrated acute onset of torticolis, stupor, and indifference to stimuli. Cutaneous hyperemia, subcutaneous and muscular hemorrhage, and peripheral edema were consistent gross findings. Histologically, clusters of lymphocytes, monocytes, and occasional acidophiles with scattered granulomas occurred in liver, kidney, and spleen. This is the first report of S. inae and C. meningosepticum as potential disease agents in R. castesbeiana. These findings suggest that a variety of bacteria may be associated with redleg and that culture results must be obtained for accurate diagnosis.

Animals↗
PubMed1979

[Yersinia enterocolitica--a still infrequently isolated pathogen in Austria (author's transl)].

Yersinia enterocolitica--recognized as a distinct taxonomic entity in 1964--belongs to the family of enterobacteriaceae. It has been isolated with increasing frequency from human and animal sources as well as from food and non-chlorinated water. Yersinia enterocolitica can produce enteritis in man, accompanied or followed in adults by erythema nodosum, arthralgia and/or acute arthritis. Rarely, septicaemia with a high mortality rate has been encountered. A cold-temperature enrichment method was used to examine 1135 faecal specimens; 11 were positive for Yersinia enterocolitica. Symptoms of enteritis were reported by all 8 patients whose faeces contained the bacterium; a brief description is given of the course of illness in each patient. Biochemical and serological properties of the isolates are discussed with special reference to some unusual results obtained with the commerical API-20 E system for identification of enterobacteriaceae when incubated overnight at 35 degrees C.

Adult↗
PubMed2005

Minimum inhibitory concentrations of tulathromycin against respiratory bacterial pathogens isolated from clinical cases in European cattle and swine and variability arising from changes in in vitro methodology.

The in vitro activity of tulathromycin was evaluated against common bovine and porcine respiratory pathogens collected from outbreaks of clinical disease across eight European countries from 1998 to 2001. Minimum inhibitory concentrations (MICs) for one isolate of each bacterial species from each outbreak were determined using a broth microdilution technique. The lowest concentrations inhibiting the growth of 90% of isolates (MIC90) for tulathromycin were 2 microg/ml for Mannheimia (Pasteurella) haemolytica, 1 microg/ml for Pasteurella multocida (bovine), and 2 microg/ml for Pasteurella multocida (porcine) and ranged from 0.5 to 4 microg/ml for Histophilus somni (Haemophilus somnus) and from 4 to 16 microg/ml for Actinobacillus pleuropneumoniae. Isolates were retested in the presence of serum. The activity of tulathromycin against fastidious organisms was affected by culture conditions, and MICs were reduced in the presence of serum.

Actinobacillus pleuropneumoniae↗
PubMed2005

Genome analysis of multiple pathogenic isolates of Streptococcus agalactiae: implications for the microbial "pan-genome".

The development of efficient and inexpensive genome sequencing methods has revolutionized the study of human bacterial pathogens and improved vaccine design. Unfortunately, the sequence of a single genome does not reflect how genetic variability drives pathogenesis within a bacterial species and also limits genome-wide screens for vaccine candidates or for antimicrobial targets. We have generated the genomic sequence of six strains representing the five major disease-causing serotypes of Streptococcus agalactiae, the main cause of neonatal infection in humans. Analysis of these genomes and those available in databases showed that the S. agalactiae species can be described by a pan-genome consisting of a core genome shared by all isolates, accounting for approximately 80% of any single genome, plus a dispensable genome consisting of partially shared and strain-specific genes. Mathematical extrapolation of the data suggests that the gene reservoir available for inclusion in the S. agalactiae pan-genome is vast and that unique genes will continue to be identified even after sequencing hundreds of genomes.

Amino Acid Sequence↗
PubMed2004

Enhanced biofilm-production in pathogens isolated from patients with rare metabolic disorders.

Biofilm-producing bacteria were isolated from the urine of 19 patients with very rare metabolic disorders including: hyperlactacidaemia (8 cases), sugar intolerance and gammopathy (1 case), cystinuria (2 cases), Parkinson's disease (1 case), lipidaemia (2 cases), hyperaminoaciduria (1 case) and others (4 cases). A total of 34 strains were collected, Gram-negative and gram-positive microorganisms were equally distributed among the slime-producing bacteria, with a prevalence of Staphylococcus epidermidis (30%) the most frequent microorganism isolated together with Escherichia coli and Proteus mirabilis that accounted for 15% of this group of strains. A quantitative assay of the biofilm production revealed that in Gram-positive pathogens it was three times greater than that observed in bacteria collected from patients not affected by metabolic diseases (p = 0.0001). In Gram-negative strains the biofilm synthesis was 2.2 times higher than those detected in the same bacteria isolated in the absence of metabolic disorders (p = 0.0033). The results observed indicate that biofilm production is enhanced in bacteria isolated from the urine of patients with metabolic disorders. It is suggested that unusual metabolites might facilitate pathogen production of biofilm found in the urine of these patients.

Bacteriuria↗
PubMed1976

Orphan airlift. Enteric pathogens isolated from Vietnamese children immigrating to the United States.

Isolation studies for bacterial and parasitic agents were carried out on stool specimens from Vietnamese infants at the time of their mass airlift to the United States. One or more bacterial pathogens were found in 49% of the 367 stool specimens cultured. The isolates included enteropathogenic Escherichia coli (161), Shigella (16), Salmonella (15), but no Salmonella typhi or Vibrio cholerae. Parasites identified in 88 stool specimens included Giardia lamblia (10), Ascaris lumbricoides (7), and Entamoeba histolytica (1). Transmission of agents to volunteers probably occurred, because 48% of 272 adults questioned had diarrhea shortly after caring for the children, and stool cultures from these adults resulted in the isolation of E coli (105), Salmonella (1), and Shigella (3).

Adult↗
PubMedDate not supplied

[The prevalence of antimicrobial susceptibility of veterinary pathogens isolated from cattle and pigs: national antibiotic resistance monitoring 2002/2003 of the BVL].

The national antimicrobial resistance monitoring determines the current quantitative resistance level of life-stock pathogens, in order to permit the evaluation and surveillance of the distribution of resistances on a valid basis. During the examination period from June 2002 to July 2003, a total of 1849 pathogens was collected, following a representative German-wide pattern in collaboration with 29 laboratories. The selection of examined bacterial strains included different specimen causing respiratory diseases in fattening pigs (Pasteurella multocida, Bordetella bronchiseptica) and cattle (Pasteurella multocida, Mannheimia haemolytica), respectively, as well as strains causing mastitis in dairy cows (Staphylococcus spp., Streptococcus spp., E. coli). Determination of the in-vitro susceptibility (minimal inhibitory concentration) to at least 17 antimicrobial agents was performed centrally by the BVL using the microdilution broth method. The findings approximately match results of an analogous study conducted in 2001, and correspondingly revealed significantly lower resistance-values in comparison to data published for Germany so far. No correlation could be established between the incidence of resistance and differing stock densities. By means of the resistance monitoring data gathered by the BVL, the risk potential of antimicrobials applied in Germany can be reliably defined. This valuable information about the epidemiological situation of resistance in Germany can be helpful to veterinarians as a decision guidance when choosing appropriate means of therapy. Accordingly, the results stated by the BVL are apt to provide an important contribution to improving the safety of food-animal products. The experiences obtained from the monitoring also show that valid data about the antimicrobial susceptibility can only be raised on an interdisciplinary approach (federal agencies, county diagnostic laboratories, universities, industry). Currently, the BVL put into practice a study with an extended spectrum of bacterial species and indications.

Animals↗
PubMed1985

Comparison of minimal inhibitory concentration and disk-diffusion antimicrobic sensitivity testing of bacterial pathogens isolated from food animals.

Disk-diffusion sensitivity tests were conducted with the antimicrobics sulfathiazole, gentamicin, erythromycin, kanamycin, penicillin, ampicillin, and spectinomycin on 300 to 350 bacterial isolates of food animal origin. The minimal inhibitory concentration of each antimicrobic was also determined for each bacterial isolate, using a microdilution technique. Results indicated that inhibitory zone sizes should be larger for some antimicrobics when testing animal pathogens than those zone sizes recommended for testing human pathogens. In addition, zone interpretive data are reported for spectinomycin, a drug for which such data were previously lacking.

Ampicillin↗
PubMed2000

Trends in antimicrobial susceptibility of bacterial pathogens isolated from patients with bloodstream infections in the USA, Canada and Latin America. SENTRY Participants Group.

From January through June of 1998, 4579 bloodstream infections (BSI) due to bacterial pathogens were reported from SENTRY hospitals in Canada, the USA and Latin America. Staphylococcus aureus, Escherichia coli, and coagulase-negative staphylococcus (CoNS) were the most common pathogens, together accounting for 55.2% of all BSI during this time period. Compared with the 5794 BSI reported from SENTRY from January through June of 1997, no major change was seen in the frequencies of occurrence of the most common bacterial causes of BSI. Between 1997 and 1998, the major change in antimicrobial resistance was an increase in oxacillin-resistance in both S. aureus and CoNS in all regions. These data demonstrate widespread antimicrobial resistance in Canada, Latin America and the USA, with a notable increase in oxacillin-resistance among staphylococci. Ongoing surveillance remains essential, and will enhance efforts to limit the scope of this worldwide problem.

Bacteremia↗
PubMed2001

Identification of a genomic island present in the majority of pathogenic isolates of Pseudomonas aeruginosa.

Pseudomonas aeruginosa, a ubiquitous gram-negative bacterium, is capable of colonizing a wide range of environmental niches and can also cause serious infections in humans. In order to understand the genetic makeup of pathogenic P. aeruginosa strains, a method of differential hybridization of arrayed libraries of cloned DNA fragments was developed. An M13 library of DNA from strain X24509, isolated from a patient with a urinary tract infection, was screened using a DNA probe from P. aeruginosa strain PAO1. The genome of PAO1 has been recently sequenced and can be used as a reference for comparisons of genetic organization in different strains. M13 clones that did not react with a DNA probe from PAO1 carried X24509-specific inserts. When a similar array hybridization analysis with DNA probes from different strains was used, a set of M13 clones which carried sequences present in the majority of human P. aeruginosa isolates from a wide range of clinical sources was identified. The inserts of these clones were used to identify cosmids encompassing a contiguous 48.9-kb region of the X24509 chromosome called PAGI-1 (for "P. aeruginosa genomic island 1"). PAGI-1 is incorporated in the X24509 chromosome at a locus that shows a deletion of a 6,729-bp region present in strain PAO1. Survey of the incidence of PAGI-1 revealed that this island is present in 85% of the strains from clinical sources. Approximately half of the PAGI-1-carrying strains show the same deletion as X24509, while the remaining strains contain both the PAGI-1 sequences and the 6,729-bp PAO1 segment. Sequence analysis of PAGI-1 revealed that it contains 51 predicted open reading frames. Several of these genes encoded products with predictable function based on their sequence similarities to known genes, including insertion sequences, determinants of regulatory proteins, a number of dehydrogenase gene homologs, and two for proteins of implicated in detoxification of reactive oxygen species. It is very likely that PAGI-1 was acquired by a large number of P. aeruginosa isolates through horizontal gene transfer. The selection for its maintenance may be the consequence of expression of any one of the genes of unknown function or the genes which allow P. aeruginosa to survive under the conditions that generate reactive oxygen species. Alternatively, one or both of the transcriptional regulators encoded in PAGI-1 may control the expression of genes in the P. aeruginosa chromosome, which provides a selective advantage for strains that have acquired this genomic island.

Cloning, Molecular↗
PubMed1999

Bacterial and fungal pathogens isolated from corneal ulcerations in domesticated elephants (Elephas maximus maximus) in Sri Lanka.

Infective corneal diseases are common among the domesticated elephants in Sri Lanka, causing morbidity including blindness leading to loss of revenue to their owners. From 140 elephants of different ages and both sexes, 36 animals (25.7%) had evidence of keratitis, corneal ulcers, corneal opacities, and some had foreign bodies in their eyes. Nine elephants (6.4%) had lesions in both eyes (6.41%). Cultures for both bacteria and fungi were obtained from 26 corneal ulcers, including the nine elephants with bilateral lesions. The other 10 animals could not be restrained for sample collection. Swabs from the normal corneas of an additional 20 elephants without signs of any ophthalmic diseases were also collected. Twenty-three of the 35 (65.71%) samples from affected corneas yielded bacterial pathogens, and 14 (40%) also had fungal isolates. None of them yielded a fungal isolate alone. The predominant bacteria isolated were Staphylococcus aureus, beta hemolytic streptococci and coliforms. Fusarium, Cladosporium, Curvularia and Aspergillus species were the primary fungal isolates. No bacteria or filamentous fungi were isolated from the eyes with the normal corneas. Microbial identification including fungal isolations is suggested in the management of infective corneal diseases in elephants.

Journal Article↗
PubMed2002

Respiratory tract pathogens isolated from patients hospitalized with suspected pneumonia in Latin America: frequency of occurrence and antimicrobial susceptibility profile: results from the SENTRY Antimicrobial Surveillance Program (1997-2000).

In spite of the recent medical advances, lower respiratory tract infections are still the most frequent infectious causes of mortality worldwide. The objective of this study was to determine the frequency of occurrence and antimicrobial susceptibility of bacterial isolates collected from hospitalized patients with pneumonia in Latin American medical centers during the first four years of the SENTRY Program. The five most frequently isolated species were (n/%): Pseudomonas aeruginosa (659/26.3%), Staphylococcus aureus (582/23.3%), Klebsiella pneumoniae (255/10.2%), Acinetobacter spp. (239/9.6%), and Enterobacter spp. (134/5.4%). P. aeruginosa demonstrated high rates of resistance to most of the antimicrobials tested. Against P. aeruginosa, the most active agents were meropenem (MIC(50), 1 microg/ml; 71.6% susceptible), amikacin (MIC(50), 4 microg/ml; 71.0% susceptible), and piperacillin/tazobactam (MIC(50), 16 microg/ml; 70.4% susceptible). Imipenem (MIC(50), 1 microg/ml; 84.1% susceptible) and meropenem (MIC(50), 2 microg/ml; 84.9% susceptible) were the most active agents against Acinetobacter spp. followed by tetracycline (MIC(50), </=4 microg/ml; 52.3% susceptible). Although the broad-spectrum cephalosporins had demonstrated excellent in vitro activity against Klebsiella pneumoniae isolates (MIC(50)s range, </= 0.12 to 0.25 microg/ml), elevated rates of resistance (46.3%-58.5%) were observed. Approximately 44.0% and 29.0% of K. pneumoniae and E. coli isolates were considered ESBL producers based on NCCLS criteria, respectively. Overall, the prevalence of methicillin-resistant S. aureus was 46.2%. The most active drugs against this pathogen were vancomycin, teicoplanin, linezolid and quinupristin/dalfopristin. In summary, the SENTRY Antimicrobial Surveillance Program has detected a high prevalence of methicillin-resistant S. aureus and multidrug resistant non-fermentative Gram-negative bacilli isolated from respiratory tract specimens of hospitalized patients with pneumonia in Latin America. Our results emphasize the importance of local surveillance programs in correctly guiding empiric therapy and local intervention programs in attempt to reduce antimicrobial resistance.

Anti-Bacterial Agents↗
PubMed1995

VCAM-1 expression and leukocyte trafficking to the CNS occur early in infection with pathogenic isolates of SIV.

This study reports on the endothelial expression of vascular cell adhesion molecule-1 (VCAM-1) in the central nervous system (CNS) early after experimental infection of rhesus monkeys (Macaca mulatta) with pathogenic and nonpathogenic simian immunodeficiency virus (SIV). Diffuse endothelial expression of VCAM-1 was observed in the CNS in all animals receiving pathogenic SIV. These findings demonstrate the rapidity with which pathogenic SIV is able to enter the CNS and induce endothelial cell activation.

Animals↗
PubMed1993

[Epidemiology of drug resistance in pathogens isolated in hospitals].

A 20-year observation showed that there were significant changes in the species composition and ratio of the sensitive and resistant variants of opportunistic bacteria constituting the main part of the pathogens causing infectious complications in somatic hospitals. However, the taxonomic structure of the pathogens changed slowly, perhaps due to the ever increasing role of the hospital strains in the development of the infections in the inpatients. The higher number of the resistant variants primarily depended on the rate of the drug use, as well as on the biological and physiological properties of the bacteria, the structure of the drugs, the nature of the resistance, etc. Therefore, the following up of the species composition of the pathogens for estimating the role of every taxon in the development of the infections with their particular localization and the determining of the relative number of the strains sensitive to the drugs used in the hospitals are the obligatory conditions for rational antibacterial chemotherapy.

Bacteria↗
PubMedDate not supplied

[Genetic determinants of Escherichia coli pathogenicity isolated from urine and feces of children with different clinical variants of urinary system infection].

In the process of examination of 156 children of different age groups 176 E. coli cultures were isolated; of these, 98 cultures were isolated from acute cystitis and pyelonephritis patients, 28--from urine in cases of aysmptomatic bacteriuria, 30--from feces in cases of asymtomatc bacteriuria and intestinal dysbacteriosis, while 20 cultures--from feces of healthy children. In these bacteria the presence of genes associated with pathogenicity islets (PI) hlyA, hlyB, cnf-1, papC, sfaG and gene irp-2 (iron-regulated protein) was established with PCR. The detection rate of PI determinants in uropathogenic E. coli (UPEC) was shown to depend on the variants of the clinical manifestation of urinary tract infection. The total detection rate of PI gene fragments in UPEC cultures of different origin was indicative of their definitely less frequent occurrence in asymptomatic bacteriuria, observed simultaneously with intestinal dysbacteriosis, in comparison with acute urological infection. Practically the same detection rate of PI determinants in E. coli, isolated in asymptomatic bacteriuria in children, reflected high probability of genetic exchange in the above-mentioned fragments and made it possible to presume the existence of DNA sites, characteristic mainly of pathogenic clones. The established heterogeneity of the detection rate of PI determinants in E. coli clinical isolates requires further study.

Acute Disease↗
PubMed2000

Comparative in vitro potency of gemifloxacin against European respiratory tract pathogens isolated in the Alexander Project.

European isolates collected in 1998 for the Alexander Project were tested for their susceptibility to ciprofloxacin, ofloxacin and a novel fluoroquinolone, gemifloxacin, which has a spectrum of activity including common and atypical respiratory pathogens. MIC90s of gemifloxacin for Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis were 0.03, 0.06 and 0.015 mg/L, respectively. On the basis of MIC90s, gemifloxacin was the most potent antimicrobial tested against S. pneumoniae and M. catarrhalis. Against H. influenzae, gemifloxacin was one tube dilution more potent than ofloxacin and one tube dilution less potent than ciprofloxacin. As resistance to currently available antimicrobial agents increases, gemifloxacin offers potential as a promising new agent for the treatment of respiratory tract infection.

Anti-Infective Agents↗
PubMed1999

Bacterial pathogens isolated from patients with skin and soft tissue infections: frequency of occurrence and antimicrobial susceptibility patterns from the SENTRY Antimicrobial Surveillance Program (United States and Canada, 1997). SENTRY Study Group (North America).

As part of the SENTRY Antimicrobial Surveillance Program, 1562 bacterial isolates were recovered from hospitalized patients with skin and soft tissue infections (SSTIs) in 30 United States (U.S.) and 8 Canadian medical centers between October and December, 1997. The overall rank order of recovery of the six most common pathogens was Staphylococcus aureus (42.6%) > Pseudomonas aeruginosa (11.3%) > Enterococcus spp. (8.1%) > Escherichia coli (7.2%) > Enterobacter spp. (5.2%) > beta-hemolytic streptocci (5.1%). With one exception, essentially the same order was observed in both the U.S. and Canada. The single exception was the Enterococcus group, which were the third most common isolate in the U.S. (9.6%), but the seventh most common isolate in Canada (3.7). Of note, 24.0% of S. aureus isolates were oxacillin resistant; vancomycin was uniformly active. Vancomycin resistance among Enterococcus spp. (16.5%) was observed only in the U.S. Several antimicrobial agents remained broadly active for SSTI isolates of P. aeruginosa, including meropenem, amikacin, tobramycin, and piperacillin with or without tazobactam. Imipenem resistance (MICs, > or = 8 micrograms/mL) was observed in 11.9% of isolates of P. aeruginosa and ceftazidime, and cefepime had equivalent activity (85.2% and 85.8% susceptible, respectively). Numerous beta-lactams, aminoglycosides and fluoroquinolones were broadly active against E. coli SSTI isolates (i.e. < 5% resistance). Extended-spectrum beta-lactamase production was uncommon both with E. coli and Klebsiella spp. in both nations. Cefepime, imipenem, and meropenem; the aminoglycosides; and fluoroquinolones were conspicuously more active against Enterobacter spp. than other agents tested. High-level, stably derepressed Amp C beta-lactamase production was commonly observed in this group (26.8%), but cefepime generally retained activity against these ceftazidime-resistant organisms. The results of this study serve to define the most common bacterial causes of SSTIs in North America, elucidate patterns of antimicrobial resistance and can be used as a basis for making initial empiric antimicrobial management decisions in hospitalized patients with such infections.

Anti-Bacterial Agents↗