Helicobacter cinaedi appears to cause recurrent cellulitis with fever and bacteremia in immunocompromised hosts. Blood cultures from immunocompromised patients with these symptoms may need special handling to isolate H. cinaedi.

No abstract

We investigated the possible mechanisms of paralysis and recovery in a patient with the acute motor axonal neuropathy (AMAN) pattern of the Guillain-Barré syndrome. The AMAN pattern of GBS is characterized clinically by acute paralysis without sensory involvement and electrodiagnostically by low compound motor action potential amplitudes, suggesting axonal damage, without evidence of demyelination. Many AMAN patients have serologic or culture evidence of recent Campylobacter jejuni infection. Pathologically, the most severe cases are characterized by wallerian-like degeneration of motor axons affecting the ventral roots as well as peripheral nerves, but some fatal cases have only minor changes in the roots and peripheral nerves, and some paralyzed patients with the characteristic electrodiagnostic findings of AMAN recover rapidly. The mechanism of paralysis and recovery in such cases has been uncertain. A 64-year-old woman with culture-proven Campylobacter upsaliensis diarrhea developed typical features of AMAN. She improved quickly following plasmapheresis. Her serum contained IgG anti-GM1 antibodies. The lipopolysaccharide of the organism bound peanut agglutinin. This binding was blocked by cholera toxin, suggesting that the organism contained the Gal(beta1-3)GalNAc epitope of GM1 in its lipopolysaccharide. Motor-point biopsy showed denervated neuromuscular junctions and reduced fiber numbers in intramuscular nerves. In contrast, the sural nerve biopsy was normal and skin biopsy showed normal dermal and epidermal innervation. In AMAN the paralysis may reflect degeneration of motor nerve terminals and intramuscular axons. In addition, the anti-GM1 antibodies, which can bind at nodes of Ranvier, might produce failure of conduction. These processes are potentially reversible and likely to underlie the capacity for rapid recovery that characterizes some cases of AMAN.

Accurate antimicrobial susceptibility testing is vital for patient care and surveillance of emerging antimicrobial resistance. The National Committee for Clinical Laboratory Standards (NCCLS) outlines generally agreed upon guidelines for reliable and reproducible results. In January 1997 we surveyed 320 laboratories participating in the New York State Clinical Evaluation Program for General Bacteriology proficiency testing. Our survey addressed compliance with NCCLS susceptibility testing guidelines for bacterial species designated a problem (Staphylococcus aureus and Enterococcusspecies) or fastidious (Streptococcus pneumoniae,Haemophilus influenzae, and Neisseria gonorrhoeae) organism. Specifically, we assessed compliance with guidelines for inoculum preparation, medium choice, number of disks per plate, and incubation conditions for disk diffusion tests. We also included length of incubation for S. aureus andEnterococcus species. We found overall compliance with the five characteristics listed above in 80 of 153 responding laboratories (50.6%) for S. aureus and 72 of 151 (47.7%) laboratories for Enterococcus species. The most common problem was an incubation time shortened to less than 24 h. Overall compliance with the first four characteristics was reported by 92 of 221 (41.6%) laboratories for S. pneumoniae, 49 of 163 (30.1%) laboratories for H. influenzae, and 11 of 77 (14.3%) laboratories for N. gonorrhoeae. Laboratories varied from NCCLS guidelines by placing an excess number of disks per plate. Laboratories also reported using alternative media forEnterococcus species, N. gonorrhoeae, andH. influenzae. This study demonstrates a need for education among clinical laboratories to increase compliance with NCCLS guidelines.

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.

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 BgIII, 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.

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<0.05) to detect listeriosis clusters caused by a specific Listeria monocytogenes subtype. Of 131 human isolates, 34 (D=0.923) ribotypes and 74 (D=0.975) PFGE types were found. Nine (31% of cases) clusters were identified by ribotype or PFGE; five (18% of cases) clusters were identified by using both methods. Two of the nine clusters (13% of cases) identified corresponded with investigated multistate listeriosis outbreaks. While most human listeriosis cases are considered sporadic, highly discriminatory molecular subtyping approaches thus indicated that 13% to 31% of cases reported in New York State may represent single-source clusters. Listeriosis control and reduction efforts should include broad-based subtyping of human isolates and consider that a large number of cases may represent outbreaks.

In East Africa, bacteremia is more common in hospitalized human immunodeficiency virus (HIV) type 1-positive than -negative patients. In 1991, blood cultures and clinical and laboratory data were obtained from 319 patients in Ivory Coast, where both HIV-1 and -2 infections occur. Forty-three bacterial, 10 mycobacterial, and 8 fungal pathogens were isolated from blood of 54 patients (17%). Pathogens isolated significantly (P < or = .05) more frequently from HIV-positive than -negative patients were nonmycobacterial bacteria, particularly Salmonella enteritidis; mycobacteria, particularly Mycobacterium tuberculosis-Mycobacterium bovis; and yeast or fungus. HIV-1 or -2 positivity was associated with a 3-fold increased risk for septicemia (P < .02). HIV-positive patients with fever or with lymphocyte counts < 1000 were more likely to be septicemic than those without these characteristics. Mortality increased significantly with HIV positivity (40% vs. 14%, P < .001) and, among HIV-positive patients, with having pathogens isolated from blood (63% vs. 33%, P < .001).