Campylobacter butzleri sp. nov. isolated from humans and animals with diarrheal illness.

Seventy-eight aerotolerant Campylobacter isolates were characterized phenotypically and by DNA hybridization (hydroxyapatite method at 50 and 65 degrees C). Two DNA relatedness groups were found. (i) Sixty-four strains belonged to aerotolerant Campylobacter DNA hybridization group 2. These organisms were isolated from humans, primarily with diarrheal illness, and animals on several continents. Strains were aerotolerant at 30 and 36 degrees C and catalase negative or weakly catalase positive, grew in media containing glycine and on MacConkey agar, were susceptible to nalidixic acid, and were resistant to cephalothin. The name Campylobacter butzleri sp. nov. is proposed for this group. (ii) DNA hybridization group 1 consisted of the type strain of Campylobacter cryaerophila and 13 additional strains isolated from 10 animals outside the United States and from three humans within the United States. This group was genetically diverse; five strains were closely related to the type strain of C. cryaerophila (DNA hybridization group 1A), and eight strains were more closely related to one another (DNA hybridization group 1B). Strains in DNA hybridization group 1B were phenotypically diverse, with two of eight strains resembling C. cryaerophila. The seven strains from DNA hybridization groups 1A and 1B which resembled C. cryaerophila and the C. cryaerophila type strain were aerotolerant only at 30 degrees C and catalase positive, did not grow in glycine or on MacConkey agar, were generally susceptible to nalidixic acid, and were resistant to cephalothin. The remaining six strains of DNA hybridization group 1B phenotypically resembled C. butzleri; however, they were generally catalase positive and susceptible to nalidixic acid and cephalothin. DNA hybridization group 1B is not designated as a separate species at this time since it cannot, with certainty, be separated genetically from C. cryaerophila or phenotypically from C. butzleri.     

Molecular subtyping to detect human listeriosis clusters

We analyzed the diversity (Simpson's Index, D) and distribution of Listeria monocytogenes in human listeriosis cases in New York State (excluding New York City) from November 1996 to June 2000 by using automated ribotyping and pulsed-field gel electrophoresis (PFGE). We applied a scan statistic (p相似文献   

In vitro susceptibilities of aerotolerant Campylobacter isolates to 22 antimicrobial agents.

We evaluated the in vitro activities of 22 antimicrobial agents against 78 human and animal isolates belonging to two aerotolerant Campylobacter species, C. cryaerophila and C. butzleri, using a broth microdilution technique. An additional 10 antimicrobial agents were included at concentrations found in selective Campylobacter media. Strains of C. cryaerophila belonged to two DNA hybridization groups: DNA hybridization group 1A, which includes the type strain of C. cryaerophila, and DNA hybridization group 1B. The aminoglycosides, fluoroquinolones, and one tetracycline (minocycline) demonstrated the most activity against all DNA hybridization groups (C. cryaerophila DNA groups 1A and 1B and C. butzleri). Most isolates were resistant to cephalosporin antibiotics, with the exception of cefotaxime, and were variably susceptible to trimethoprim-sulfamethoxazole. C. cryaerophila DNA hybridization group 1A isolates were generally susceptible to the tetracyclines, chloramphenicol, nalidixic acid, azithromycin, erythromycin, and roxithromycin and moderately susceptible to clindamycin, trimethoprim-sulfamethoxazole, ampicillin, and ampicillin-sulbactam. The MICs of tetracyclines were higher for C. butzleri and C. cryaerophila DNA hybridization group 1B isolates than for C. cryaerophila DNA hybridization group 1A isolates, but most strains were still susceptible to doxycycline and tetracycline; all isolates were susceptible to minocycline. C. butzleri and C. cryaerophila DNA hybridization group 1B isolates were generally resistant to the macrolide antibiotics (including erythromycin), chloramphenicol, clindamycin, nalidixic acid, ampicillin, and trimethoprim-sulfamethoxazole. Differences in antimicrobial susceptibility between aerotolerant Campylobacter species and more common Campylobacter species, e.g., C. jejuni, suggest that different treatment strategies may be necessary. Strains of all three DNA hybridization groups of aerotolerant Campylobacter isolates were susceptible to colistin, polymyxin B, and rifampin at concentrations commonly used in selective media. These results suggest that primary isolation methods for Campylobacter species may need to be modified to include aerotolerant Campylobacter strains.     

Changes in levels of ADP-ribose polymers in rat liver during 2-acetylaminofluorene-induced hepatocarcinogenesis

The exposure of rats to the carcinogen 2-acetylaminofluorene(2-AAF) results in the accumulation of DNA-damaging adducts.The inability of cells to repair such damage adequately is aputative causal event in chemical carcinogenesis. It has beenshown that one cellular response to DNA damage that leads toDNA repair is poly(ADP-ribosyl)ation of nuclear proteins. Toexamine the possible existence of an altered poly(ADP-ribosyl)ationresponse to 2-AAF-mediated damage of rat liver DNA, tissue ADP-ribosepolymer levels were determined during various stages of 2-AAF-mediatedcarcinogenesis. 2-AAF was administered to rats in a discontinuousfeeding regimen comprised of five consecutive cycles, each cycleconsisting of 3 weeks on 2-AAF diet followed by 1 week of recoveryon a control diet without 2-AAF. During cycle one of 2-AAF administration,rat liver ADP-ribose polymer levels increased 3-fold over thatfound in livers of rats fed only the control diet. In contrast,when rats were administered the non-genotoxic liver mitogen4-AAF for one cycle, no significant elevation occurred in ADP-ribosepolymer levels. Elevated ADP-ribose polymer production was alsoobserved during cycles two and three of 2-AAF administration.However, during cycles four and five of 2-AAF administration,a period when rats administered 2-AAF acquire a high risk forhepatocarcinogenesis, an altered pattern of ADP-ribose polymerproduction occurred in rat livers. ADP-ribose polymer levelsin these rat livers remained low, similar to levels found incontrol rat livers, despite the administration of 2-AAF. Whenthe livers from rats fed either one or five cycles of 2-AAFwere analyzed for possible decreases in the levels of tissueNAD+, the substrate for poly(ADP-ribose) polymerase, no changesin relative abundance were found. In addition, analysis of poly(ADP-ribose)polymerase activity showed no decrease at five cycles of 2-AAFadministration. These results indicated that at late stagesof 2-AAF-induced hepatocarcinogenesis, 2-AAF does not inducean expected increase in ADP-ribose polymer levels, and suggestedthat significant changes in DNA repair may occur at a time justpreceding an increased risk for developing liver cancer.     

Evaluation of 10 methods to distinguish epidemic-associated Campylobacter strains.

We compared four phenotypic and six genotypic methods for distinguishing Campylobacter jejuni strains from animals and humans involved in four epidemics. Based on a comparison with epidemiologic data, the methods that correctly identified all strains in three milkborne outbreaks and one waterborne outbreak were heat-stable and heat-labile serotyping; multilocus enzyme electrophoresis (MEE); DNA restriction endonuclease analysis with BglII, XhoI, PvuII, or PstI; and Southern blot and hybridization of PvuII- and PstI-digested DNA with Escherichia coli 16S and 23S rRNA (ribotyping). Biotyping, phage typing, plasmid analysis, and probing of BglII and XhoI DNA digests with C. jejuni 16S rRNA genes failed to correctly separate one or more strains. MEE, restriction endonuclease analysis, and ribotyping were the most sensitive methods and identified nine types among the 22 strains. These methods were also capable of further distinguishing strains within the same serotype. Data from MEE were also analyzed to calculate genetic relatedness among strains. Serotyping was the most discriminating phenotypic method, with eight and seven types distinguished by the heat-stable and heat-labile methods, respectively. MEE and ribotyping had several advantages over the other methods because they measure relatively stable and significant chromosomal differences and are applicable to other species and genera. These methods, however, are complex and not easily quantified; they are currently limited to specialized laboratories. When antisera are available, serotyping appears to be an effective and more practical approach to the identification of epidemic-related strains.     

Detection of Mycoplasma genitalium in women with laparoscopically diagnosed acute salpingitis

OBJECTIVES: Mycoplasma genitalium has been associated with cervicitis, endometritis, and tubal factor infertility. Because the ability of this bacterium to ascend and infect the fallopian tube remains undefined, we performed an investigation to determine the prevalence of M genitalium in fallopian tube, endometrial, and cervical specimens from women laparoscopically diagnosed with acute salpingitis in Nairobi, Kenya. METHODS: Women presenting with pelvic inflammatory disease were laparoscopically diagnosed with salpingitis. Infection with M genitalium in genital specimens was determined by polymerase chain reaction (PCR). RESULTS: Of 123 subjects with acute salpingitis, M genitalium was detected by PCR in the cervix and/or endometrium in nine (7%) participants, and in a single fallopian tube specimen. In addition, those infected with M genitalium were more often HIV infected than women not infected by M genitalium (seven of nine (78%) v 42 of 114 (37%), p<0.03). CONCLUSIONS: M genitalium is able to ascend into the fallopian tube, but its association with tubal pathology requires further investigation.     

Specimen dilution improves sensitivity of the amplified Mycobacterium tuberculosis direct test for smear microscopy-positive respiratory specimens

Specimen dilution has been proposed as a strategy to minimize amplified Mycobacterium tuberculosis direct (MTD) test inhibition (N. Pollock, J. Westerling, and A. Sloutsky, Am. J. Clin. Pathol. 126:142-147, 2006; A. Sloutsky, L. L. Han, and B. G. Werner, J. Clin. Microbiol. 42:1547-1551, 2004). We evaluated the impact of respiratory specimen dilution on MTD test accuracy in a public health laboratory. The difference in MTD test sensitivity between the dilution and conventional methods was 15.9% (P = 0.001) for smear microscopy-positive specimens and −3.6% (P = 0.38) for smear microscopy-negative specimens.     

Molecular epidemiologic techniques in analysis of epidemic and endemic Shigella dysenteriae type 1 strains.

During 1988 the number of Shigella dysenteriae type 1 infections reported in the United States increased fivefold. To determine if recent isolates from Mexico were related to those that caused epidemics of dysentery worldwide, Southern hybridization analysis was done with Shiga toxin and ribosomal RNA gene probes. Western hemisphere and Eastern Hemisphere strains differed by the size of a single EcoRI fragment carrying the Shiga toxin genes. Three ribosomal DNA (rDNA) patterns were observed, which correlated with the strain's continental origin for 81 of 83 isolates tested. Together the Shiga toxin and rDNA probe results indicated that recent Mexican isolates were chromosomally similar to earlier Central American isolates and distinct from Asian and African strains. This suggests there has been no significant exchange of organisms between continents in recent decades and that the 1988 outbreak in Mexico was caused by strains present in Central America since at least 1962.     

Uncommon Campylobacter species in infant Macaca nemestrina monkeys housed in a nursery.

Studies were conducted to characterize 18 isolates of Campylobacter spp. that could not be identified as either Campylobacter jejuni or C. coli. The isolates were cultured from specimens from 13 of 18 infant nonhuman primates during a prospective epidemiologic study reported previously. Phenotypic tests, DNA hybridization, and analysis of DNA coding for rRNA identified the isolates as C. butzleri (seven isolates), C. hyointestinalis (seven isolates), and C. fetus subsp. fetus or C. fetus subsp. fetus-like organisms (four isolates). Ribotype and polyacrylamide gel electrophoresis patterns indicated that there was heterogeneity among the isolates of C. butzleri and C. fetus subsp. fetus-like organisms.     

Evaluation of the indoxyl acetate hydrolysis test for rapid differentiation of Campylobacter, Helicobacter, and Wolinella species.

A total of 410 well-defined Campylobacter, Helicobacter, and Wolinella strains, comprising 26 named species, subspecies, and defined groups, were tested for indoxyl acetate hydrolysis by a disk method by using disks prepared at the Centers for Disease Control, Atlanta, Ga. All C. coli (43 strains), C. cryaerophila (34 strains), C. fennelliae (5 strains), C. fennelliae-Campylobacter-like organism 3 (2 strains), C. jejuni (66 strains), C. jejuni subsp. doylei (3 strains), hippurate-negative C. jejuni-C. coli (15 strains), "C. upsaliensis" (39 strains), H. mustelae (5 strains), W. curva (1 strain), and W. recta (1 strain) hydrolyzed indoxyl acetate. Four strains gave weak positive reactions, and the remaining 196 strains, which belonged to 15 species, subspecies, and defined groups, gave negative reactions. Of the 410 study strains, 246 and 125 strains were tested for indoxyl acetate hydrolysis by a disk method and a tube method, respectively, by using commercially produced disks. The disk method, regardless of source, required less time and interpretation than the tube method did. Better differentiation between Campylobacter spp. was obtained with the indoxyl acetate test than with the trimethylamine N-oxide test. The indoxyl acetate disk distinguished C. lari from C. jejuni and C. coli, C. cinaedi from C. fennelliae, and H. pylori from H. mustelae and suggested that W. succinogenes could be differentiated from W. recta and W. curva. The indoxyl acetate disk method could be performed in 5 to 30 min, was easy to read and interpret, and should be useful as a routine diagnostic test for identification of Campylobacter spp.