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PubMed2005

Characterization of clinical isolates of pathogenic Nocardia strains and related actinomycetes in Thailand from 1996 to 2003.

In Thailand from 1996 to 2003, 171 strains of pathogenic aerobic actinomycetes from clinical specimens were isolated. Of those strains, 134 were mycolic acid containing actinomycetes, including 96 strains of Nocardia species. Others included 10 strains of Gordonia, 14 strains of Rhodococcus, and 22 strains of Mycobacterium. One strain each of the genera Tsukamurella and Corynebacterium were also isolated. Also identified were 27 strains of non-mycolic acid containing actinomycetes. Our identification studies of 96 strains of Nocardia species showed that significant pathogens in Thailand were N. beijingensis (18 strains), N. cyriacigeorgica (13 strains), and N. farcinica (34 strains); the most prevalent species was N. farcinica (35.4%). We also isolated four strains of N. asiatica, five strains of N. asteroides sensu stricto, four strains of N. nova, seven strains of N. otitidiscaviarum, eight strains of N. transvalensis, and two strains of N. pseudobrasiliensis.

Actinobacteria↗
PubMed1993

Randomized comparative study of cefepime and cefotaxime in the treatment of acute obstetric and gynaecological infections.

Patients with presumed acute gynaecological infections were randomized (2:1) to receive cefepime 2 g every 12 h (n = 159) or cefotaxime 2 g every 8 h (n = 72), both im or by a 30-min i.v. infusion. For evaluation of efficacy, patients were required to have a bacteriologically documented infection, with at least one pathogen isolated susceptible to both drugs. Duration of treatment was 2-8 days in the 95 cefepime-treated patients and 3-10 days in the 36 cefotaxime-treated patients with evaluable infections; approximately three-quarters of the patients in each group were treated for 4-5 days. Clinical response was satisfactory in 81/95 (85%) of the evaluable cefepime recipients and 30/36 (83%) of the evaluable cefotaxime recipients (P = 0.802). In total, 211 (85%) of the 247 pathogens isolated from evaluable cefepime recipients were eradicated, compared with 98 (90%) of 109 pathogens isolated from evaluable cefotaxime recipients. All pathogens were eradicated in 77 (81%) cefepime-treated patients and in 31 (86%) cefotaxime-treated patients (P = 0.379). Overall response to treatment, calculated by combining clinical response and individual patient bacteriological response, was considered effective, partially effective or ineffective in 77%, 13% and 11% of cefepime-treated patients respectively and in 75%, 19% and 6% of cefotaxime-treated patients respectively (P = 0.932 for effective response). Adverse clinical events were reported by 68 (43%) of 159 cefepime recipients and by 26 (36%) of 72 cefotaxime recipients (P = 0.342); adverse events were deemed drug-related in 6% of cefepime recipients (diarrhoea, rash and headache) and in 1% of cefotaxime recipients (diarrhoea, pruritus and rash). Treatment was discontinued prematurely due to adverse events in five cefepime-treated patients and in one cefotaxime-treated patient (P = 0.476). Local intolerance was reported by 33 (21%) of the 159 cefepime-treated patients and by 14 (19%) of the 72 cefotaxime-treated patients receiving drug via the iv route alone; none of the patients discontinued treatment because of local intolerance. Laboratory test abnormalities were observed in a small number of patients in each group (1-8%), but none warranted discontinuation of treatment. Cefepime 2 g bd appears to have efficacy and safety comparable to that of cefotaxime 2 g tid in the treatment of acute obstetric and gynaecological infections.

Adolescent↗
PubMed1983

Isolation and pathogenicity of provisional serovar 1621-54 of "Shigella" from imported cynomolgus monkeys.

The provisional serovar 1621-54 of "Shigella" was isolated from 36 (13.2%) of 273 cynomolgus monkeys newly imported into Tsukuba Primate Center for Medical Science (TPC) from Indonesia during the period from 1980 through 1981. The biochemical properties of the isolates were in good agreement with those of previously described provisional "Shigella" serovar 1621-54. Clinically, 13 (36.1%) of 36 monkeys being positive for the organisms excreted diarrheal stools on arrival at TPC. In addition, the organisms were isolated also from three other monkeys contracting dysentery during the quarantine period at TPC. One of them died 2 days after the onset of dysentery. Histopathological findings of this case were essentially the same as those of Shigella-infected monkeys. Pathogenicity of the isolates was examined in three experimental infection models; (1) the infection model using cultured HeLa-S3 cells, (2) the keratoconjunctival infection model of the guinea pig, and (3) the intestinal infection model of the cynomolgus monkey. All the strains tested showed positive results in these experimental models, causing intracellular penetration and multiplication in HeLa-S3 cell cultures, keratoconjunctivitis in guinea pigs, and dysentery in cynomolgus monkeys. These results indicate that provisional "Shigella" serovar 1621-54 is a causative agent of dysentery in man as well as in monkeys.

Animals↗
PubMed2001

Incidence of the cblA major subunit pilin gene amongst Burkholderia species.

PCR-amplification has been used to screen 75 isolates of the Burkholderia cepacia complex for the cblA pilin gene. PCR-amplified products of the correct size (664 bp) were cloned and sequenced and the sequences compared. Apart from in the control, epidemic cystic fibrosis (CF)-associated B. cepacia lineage we also identified, for the first time, cblA genes in a unique, non-CF clinical isolate from France and a plant (onion) pathogenic isolate from Italy. The sequence of the cblA gene amplified from the clinical isolate was more diverged from the epidemic lineage than that amplified from the onion pathogenic isolate.

Amino Acid Sequence↗
PubMed2005

New sesquiterpenic phytotoxins establish unprecedented relationship between different groups of blackleg fungal isolates.

A comprehensive search for sesquiterpenic metabolites produced by isolates of the blackleg fungus [Leptosphaeria maculans (Desm.)] Ces. et de Not. [asexual stage Phoma lingam (Tode ex Fr.) Desm.] revealed that an isolate pathogenic on both canola and brown mustard (IBCN 18) and two isolates pathogenic on brown mustard (Laird 2 and Mayfair 2) produced similar sesquiterpenes. The isolation, chemical structure elucidation, and phytotoxicity of these new sesquiterpenes with silphinene and selinene type skeletons is reported. This is the first time that an isolate virulent on canola and brown mustard is found to produce metabolites characteristic of both virulent (sirodesmins) and avirulent (phomalairdenones) L. maculans/P. lingam. In the context of grouping the various isolates of L. maculans/P. lingam, this work suggests an additional pathogenicity group comprising isolates that produce both sirodesmins and phomalairdenones and are virulent on both canola and brown mustard.

Ascomycota↗
PubMed2000

Localization of fungal fimbriae by immunocytochemistry in pathogenic and nonpathogenic isolates of Venturia inaequalis.

Pathogenic and nonpathogenic isolates of Venturia inaequalis were grown in liquid culture. Hyphae were treated with two types of fimbrial antiserum (AU- and AV-1) and examined by immunofluorescent microscopy, in order to establish the distribution of fimbrial epitopes in whole cell mounts. The AV-1 antiserum was specific for the glycoprotein subunits while the AU-antiserum was specific for the protein moieties present on the fimbriae of Mycobotryum violaceum. The use of fimbrial antiserum with immunocytochemistry and transmission electron microscopy demonstrated a clear distinction between pathogenic and nonpathogenic isolates of V. inaequalis, based on the appearance of the fungal cell wall and the distribution of fimbrial epitopes labeled with AV-1 antiserum and immunogold complex. In actively growing hyphae of the pathogenic isolate, characterized by distinct cellular organelles, small vacuoles, and lipid bodies, fimbrial epitopes were concentrated in the fungal cell wall and were present minimally on the outer surface. In contrast, actively growing hyphae of the nonpathogenic isolate of V. inaequalis had extensive fine hair-like protrusions in the fungal cell wall which labeled with the AV-1 antiserum and immunogold. The distribution of fimbrial epitopes in V. inaequalis was highly dependent on the developmental growth stage of the fungal mycelium. Aging mycelia in both the pathogenic and nonpathogenic isolates of V. inaequalis were characterized by a large central vacuole and no label. In the pathogenic and nonpathogenic isolates of V. inaequalis grown in vitro, the distribution of fimbrial glycoprotein epitopes provided a more complex profile than that seen in M. violaceum.

Antibodies↗
PubMed1992

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from urinary tract infections (1988). II. Background of patients].

Clinical background was investigated on 916 bacterial strains isolated from patients with urinary tract infections (UTIs) in 9 hospitals during the period from June to November, 1988. 1. Distribution of sexes, ages and infections: Among males, fifties and older were most frequent and most of them had complicated UTIs. Among females, most cases among twenties or thirties were uncomplicated UTIs. Forties and older cases were most frequent and complicated UTIs were more frequent among them than among patients in twenties and thirties. 2. Distribution of sexes, ages and pathogens isolated from UTIs: In males, Pseudomonas spp. and Enterococcus spp. were frequently isolated. In contrast, in females, Escherichia coli was the most frequent. In thirties, E. coli was not the most frequently isolated bacterium. Frequency of Pseudomonas spp., other non-fermented Gram-negative rods and Enterococcus spp. were greater among patients with higher ages. 3. Administration of antibiotics and pathogens isolated from UTIs: (1) Before administration: In uncomplicated UTIs, E. coli accounted for the majority of causative organisms. In complicated UTIs, particularly in those cases with indwelling catheter, Enterococcus spp. and Pseudomonas spp. were rather frequently isolated. (2) After administration: In complicated UTIs, higher number of pathogens were isolated. Pseudomonas spp. and Enterococcus spp. were the most frequent. Distribution of pathogens isolated from complicated UTIs without indwelling catheter was similar to that before antibiotic administration.

Adult↗
PubMed1999

Molecular reidentification of human pathogenic Trichoderma isolates as Trichoderma longibrachiatum and Trichoderma citrinoviride.

Several species of the well-known saprophytic genus Trichoderma have been identified as the cause of infections in immunosuppressed humans. Because the differentiation and identification of Trichoderma species based on morphological characters only, is very difficult, two molecular approaches were applied for species identification. Six human pathogenic Trichoderma isolates were investigated by PCR-fingerprinting and analysis of ribosomal DNA internal transcribed spacer (ITS) sequences and compared with the corresponding data sets established for described species of the genus. Five of these strains were identified as T. longibrachiatum, whereas one single strain turned out to be T. citrinoviride. Both species are very closely related and belong to Trichoderma section Longibrachiatum. These data indicate that the occurrence of pathogenic Trichoderma strains may be restricted to species of section Longibrachiatum.

DNA Fingerprinting↗
PubMed1978

The role of certain oxidative enzymes, catalase, and beta-glucosidase on virulence of Cephalosporium maydis.

Isolates of Cephalosporium maydis varied in their pathogenicity to D.C. 67 maize cultivar from highly to weakly pathogenic. Highly pathogenic isolates showed lower activity of polyphenol oxidase, peroxidase, cytochrome oxidase, and beta-glucosidase enzymes and higher activity of catalase and dehydrogenase than weakly pathogenic isolates. Enzymes production by the tested isolates increased as the culture age increased; except in case of catalase enzyme, the reverse action was detected. The role of these enzymes in the virulence of C. maydis is suggested and discussed.

Acremonium↗
PubMed1990

Infection on a gynecologic oncology service.

Little information is available pertaining to infectious morbidity in women with genital malignancy. To define the magnitude of this problem, all patients admitted to the gynecologic oncology services at the University of Michigan Medical Center between January 1, 1986, and December 31, 1986, were followed prospectively for the development of infectious morbidity. One hundred nine bacteriologically confirmed infections occurred in 297 patients during 510 admissions. An additional 31 postoperative patients received empiric therapy for presumed infection. Urinary tract (54) and wound (22) infections were the most commonly confirmed infections. The pathogens isolated from oncology patients were significantly different in frequency of isolation and antibiotic sensitivity when compared with pathogens isolated from women developing infections on the benign gynecology service. Women with genital malignancies are at high risk for the development of a variety of infections by resistant pathogens, emphasizing the importance of obtaining cultures prior to initiation of therapy and carefully selecting the antibiotics to be prescribed.

Anti-Bacterial Agents↗
PubMed1999

Isolation of respiratory bacterial pathogens from the throats of healthy infants fed by different methods.

Most bacterial infections are caused by organisms that have already colonized the host. Bacterial attachment to pharyngeal cells and proliferation may be necessary to infect the lower respiratory tract or middle ear. We investigated the incidence of pathogenic bacteria isolated from the throat of healthy infants with different feeding methods. The protecting role of breastmilk is also discussed. The incidence of respiratory bacterial pathogens isolated from the oropharynx of 113 normal infants with different feeding methods was investigated. Group A beta haemolytic Streptococcus, Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis were selected as respiratory bacterial pathogens. No respiratory bacterial pathogens were detected in breastfed and mixed-fed infants. Haemophilus influenzae and Moraxella catarrhalis were isolated from the oropharynx of formula-fed infants. The incidence of respiratory bacterial pathogens did differ among infants with different feeding methods. These results suggest that breastmilk may inhibit the colonization by respiratory bacterial pathogens of the throat of infants, by enhancing mucosal immunity against respiratory tract infection.

Bacteria↗
PubMed2004

Growth and pathogenicity of isolates of the fungus Metarhizium anisopliae against the parasitic mite, Psoroptes ovis: effects of temperature and formulation.

Psoroptes mites (Acari: Psoroptidae) are important ectoparasites of mammals, and are of particular economic significance as the agents of mange in sheep. To be effective against mites, putative fungal biocontrol agents must be able to operate at the relatively high temperatures and humidities found at the sheep skin surface. To consider this, the growth rates of different isolates of the entomopathogenic fungus Metarhizium anisopliae (Metschnikoff) Sorokin (Deuteromycotina: Hyphomycetes) were compared and the pathogenicity of these isolates against Psoroptes derived from rabbits (Psoroptes ovis Hering, syn P cuniculi) were evaluated at temperatures between 28 degrees C and 40 degrees C, and when formulated in either Tween 80 or silicone oil. For this study four multi-conidia, arthropod-derived, isolates of M anisopliae were used: from the USA, France, Denmark and Brazil. One single-conidia culture derived from the US isolate was also included in the investigation. Fungal growth was higher at the lower temperatures and none of the isolates grew at 40 degrees C. The growth of the US and single-conidia isolate declined markedly with temperature. In contrast, the Danish, French and Brazilian isolates grew almost as well at 32 degrees C and 35 degrees C as at 28 degrees C and 30 degrees C. The French and Brazilian isolates showed some growth at 37.5 degrees C but the Danish and US isolates did not. The number of fatal infections which resulted from exposure of mites to the fungal isolates was also strongly influenced by temperature. At 30 degrees C all isolates gave between 70 and 90% infection. The number of infections declined with increasing temperature and no infections were seen at 40 degrees C. However, the French and Danish isolates of M anisopliae gave higher numbers of infections than the other isolates at elevated temperatures. When formulated in silicone oil, significantly higher levels of infection were obtained than when formulated in Tween 80, even at the relatively high temperature of 37.5 degrees C. It is suggested that high-temperature adapted isolates of M anisopliae formulated in silicone oil offer good candidates as control agents under the conditions found at the sheep skin surface.

Animals↗
PubMed1991

Screening of children for enteric bacterial pathogens in the outborn neonatal ward in Lagos, Nigeria.

Babies, on admission into a neonatal ward at the Lagos University Teaching Hospital, had their rectal swab specimens examined bacteriologically and screened for enteric bacterial pathogens over a one-year-period at two-week intervals. It was found that on the average there were 3 (9.68%) enteric bacterial pathogens out of an average of 31 admissions at each screening period. The enteric bacterial pathogens isolated included: non-typhoid salmonellae, which accounted for 55 (80.88%) isolates out of the 68 enteric bacterial pathogens, Salmonella typhi 2.94%, Shigella dysenteriae 2.94%, Shigella flexneri 4.41%, S. boydii 1.47%, S. sonnei 1.47%, Campylobacter jejuni 1.47% and Enteropathogenic Escherichia coli (EPEC) 2.94%. The main clinical conditions associated with those babies in whom the enteric pathogens were isolated included sepsis, prematurity, neonatal jaundice and tetanus. It is concluded that the enteric bacterial pathogens, even though they were not directly associated with diarrhoeal disease in the newborns in this study, might have contributed to other illnesses like sepsis and meningitis. It is also noteworthy that the enteric bacterial pathogens isolated sporadically from the babies could have been over-looked in view of the fact that it is not conventional to search for enteric bacterial pathogens in babies without diarrhoea on admission. Rectal swab investigations could provide additional information which might be of epidemiological importance in ill neonates in the clinical settings that prevail in developing countries.

Bacteria↗
PubMed1975

A strain of pathogenic Naegleria isolated from a human nasal swab.

The 161A strain of Naegleria isolated from a human nasal swab and reported earlier was further studied for its growth pattern, cyst-wall appearance, cytopathic effect on primary monkey kidney cells, and pathogenicity in mice. Results obtained in the study establish the pathogenic status of this strain. This constitutes the first isolation of a pathogenic Naegleria from a human nasal cavity.

Amoeba↗
PubMed2004

Molecular characterization of Aphanomyces species associated with legumes.

The identification of plant-associated isolates of Aphanomyces spp. has been mainly based on morphological characters. These types of features, however, can be unreliable due to their high variation and degree of overlap between different taxa. In this work, strains of Aphanomyces, with plant pathogenic and non-pathogenic characteristics, derived mainly from the roots of several leguminous crops in Sweden, as well as a number of reference strains of A. euteiches, A. cladogamus and A. cochlioides were compared by morphology, AT-rich DNA RFLPs and sequence analysis of the total ITS/5.8S rRNA gene region. Parsimony analysis of the sequence data of the total ITS region of 21 strains separated the taxa at the specific level, while two intra-specific groups were also detected within A. euteiches. One comprised all pathogenic isolates of A. euteiches from Sweden, together with two isolates from France and the USA. These isolates formed a homogenous group with identical ITS regions and a single AT-rich DNA RFLP banding pattern. The second ITS subspecific group included reference strains of A. euteiches with preferential pathogenicity to bean and alfalfa, all of which originated from the USA. The bean and alfalfa pathotypes were further distinguished by their different AT-rich DNA RFLPs. The non-pathogenic isolates of Aphanomyces from Sweden associated with the roots of several legumes, formed a genotypically uniform group with an identical ITS sequence and a single AT-rich DNA RFLP pattern. The ITS sequence of this group was identical to that of reference strains of A. cladogamus, suggesting that the non-pathogenic isolates belonged to this species. Intra-specific AT-rich DNA banding profiles were also obtained for isolates of A. cladogamus and these patterns corresponded well to the original hosts.

DNA, Ribosomal Spacer↗
PubMed2005

[Studies on extracellular virulent factors produced by potential pathogenic bacteria isolated from abalone postlarvae and biofilms].

To find out the potential pathogen(s) that caused massive death of abalone postlarvae( Haliotis diversicolor supertesta ) in Southern China, 105 bacterial strains were isolated from the water, whitened postlarvae and their biofilms of an abalone farm in Guangdong Province. Extra-cellular protease, gelatinase, lipase as well as haemolysis tests were performed on them. Lysophospholipase (Tlh)-targeted PCR was also carried out in order to reveal if the haemolysis caused by bacterial strains were related to Tlh. Results showed that 35 out of 105 strains possessed extra-cellular enzymatic abilities and strains 1, 2, 3, 5, 9 and 16 were the most powerful ones of all. Among these 35 strains, 85.6% strains (30/35) possessed haemolytic activities on goat blood agar and specific PCR revealed that 16 strains were PCR positive, indicating that they contained Tlh genes. In order to identify these strains, API 20 E strips were employed and results indicated that 50% were vibrios, among them Vibrio alginolyticus composed 70% of the vibrio population. In conclusion, compared to other strains, 6 Vibrio alginolyticus (strain 1, 2, 3, 5, 13, and 16 ) and 2 Vibrio parahaemolyticus (strain 9 and 21) which all were isolated from whitened abalone postlarvae, warrant further studies due to their better abilities in extra-cellular enzyme(s) production and/or haemolytic activities.

Animals↗
PubMedDate not supplied

[Isolation of pathogenic bacteria in pasteurized type C milk sold in Recife City, Pernambuco, Brazil].

In order to improve information about the microbiological quality of the milk commercially available in the city of Recife, 250 samples of pasteurized type-C milk and 50 samples of raw milk were analyzed for Yersinia enterocolitica and Listeria monocytogenes and verify the possible occurrence of Yersinia enterocolitica and Listeria monocytogenes. These bacteria can develop in refrigeration temperatures and are responsible for food-born diseases. Neither Y. enterocolitica nor L. monocytogenes were found in the samples analyzed. However, the presence of Y. intermedia and Y. frederiksenii was detected, these environmental species behave as opportunist pathogens. Through the methodology used for Listeria isolation, one isolate of Salmonella Montevideo was obtained from a sample of pasteurized milk and another isolated from one sample of raw milk. Besides these, several other bacteria species were found. It is likely that the large microbiota present in the samples and the procedures employed to destroy it could have hindered the isolation of Y. enterocolitica and L. monocytogenes.

Animals↗
PubMed2005

Comparison of physiological, cytopathogenic and immunological properties between two environmental isolates of Acanthamoeba spp.

The aim of this study was to determine whether pathogenic and less-pathogenic isolates of environmental Acanthamoeba exhibit differences in adhesion to human erythrocytes. Based on physiological properties of temperature, tolerance, and rapid growth, Acanthamoeba were divided into pathogenic and less-pathogenic isolates. Acanthamoeba were tested for their ability to produce cytopathic effects (CPE) using two human cell lines, HEp-2 and KB cells. Both ameba isolates caused CPE to both cell lines with the same pattern without significant difference. Human erythrocytes from 20 healthy volunteers were used to study the erythrocyte reactivity of Acanthamoeba by co-incubation with trophozoites. The pathogenic Acanthamoeba exhibited significantly higher erythrocyte adhesion as compared to the less-pathogens (p<0.05). Erythrocyte activity occurred in the presence of plasma in all blood samples, suggesting the role of plasmatic components and contact-dependent mechanisms to produce host cell cytotoxicity. The present results showed correlation between the physiological properties and erythrocyte reactivity of Acanthamoeba.

Acanthamoeba↗