Reverse transcription polymerase chain reaction-based method for selectively detecting vegetative cells of toxigenic Clostridium difficile.

The laboratory diagnostic methods for Clostridium difficile infection (CDI) include toxigenic culture, enzyme immunoassays (EIAs) to detect the toxins of C. difficile, and nucleic acid amplification tests (NAATs) to detect C. difficile toxin genes, but each of these methods has disadvantages; toxigenic cultures require a long time to produce results, EIAs have low sensitivity, and NAATs that target DNA cannot distinguish vegetative cells from spores and dead cells. Here we report a new detection method that uses reverse transcription polymerase chain reaction to target the toxin-gene transcripts. This method was able to specifically detect the vegetative cells of toxigenic C. difficile in fecal samples in spike tests, with a minimum detection limit of 5 × 10(2) colony-forming units per 100 mg of stool specimen. The performance of this method was also demonstrated in a pilot scale evaluation using clinical fecal specimens, which showed that this method may be more sensitive than EIA and requires a shorter time than toxigenic culture. This method could potentially be applied in the clinical laboratory to detect C. difficile in fecal specimens. The ability of this method to discriminate the presence of vegetative cells from spores and dead cells could help to further the understanding of CDI.

Mycotic abdominal aortic aneurysm caused by Campylobacter fetus: a case report and literature review.

Campylobacter spp. usually cause gastrointestinal infections, but among them, Campylobacter fetus is a well-known organism causing mycotic abdominal aortic aneurysm (MAAA), which requires proper surgical intervention and antibiotic therapy. We report a 65-year-old man who was successfully treated by an in situ operation using a rifampicin (RFP)-bonded J-Graft for C. fetus-induced MAAA. We performed a review of the English literature on MAAA caused by C. fetus and summarized the results of the cases (28 cases). All but 2 of the patients (92.9%) were men. Blood culture and arterial wall culture were positive in 63% and 73.1% of the cases, respectively. Aneurysm rupture was seen in half of the patients, and approximately half of those patients died. Among the 18 patients who underwent in situ graft replacement, only 1 patient (5.6%) died after surgery. Antibiotic therapy was performed for more than 1 month in most cases, and overall mortality rate was 25.9% (7 of 27 cases, 3 deaths before the operation and 4 deaths after surgery). Although extra-anatomic bypass has been conventionally performed after complete resection of an MAAA, the utility of in situ surgery has generally been recognized. Our review suggests that the in situ operation can be a choice also in cases of C. fetus-associated MAAA. Furthermore, our case suggested the clinical utility of a newly manufactured prosthetic graft, J-Graft, for such surgical treatment.

Clinical characteristics of Raoultella ornithinolytica bacteremia: a case series and literature review.

Raoultella ornithinolytica is a rare pathogen in human infection and bacteremic cases had been scarcely reported. For further comprehension of the rare infection, we summarized clinical characteristics of 6 cases that were detected at our medical facility and 5 cases from previous literature. The most common infectious focus was biliary infection and elderly patients with a history of any biliary intervention or malignancy were considered to be at a great risk for the infection. The prognosis of the patients was quite satisfactory. Bacterial identification in this report was performed on the basis of biochemical tests alone, and further investigations by molecular analysis are required to confirm our findings.

Chromobacterium violaceum nosocomial pneumonia in two Japanese patients at an intensive care unit.

Chromobacterium violaceum is sensitive to temperature and the infection is usually confined to tropical or subtropical regions. Since Japan has a warm climate, C. violaceum has been scarcely isolated from clinical specimens. With global warming, however, the geographical distribution of C. violaceum infection is likely to change. We report two cases of C. violaceum nosocomial pneumonia that occurred at an intensive care center in Japan. C. violaceum was first detected from a patient in the same center as a pathogenic organism of pneumonia. Later, the organism was isolated from sputum and a ventilator circuit tube of another patient in the center. The two patients were admitted to the center in nearby beds for several days. All of the pathogens were confirmed to be C. violaceum by the nucleic acid sequence of the 16S rRNA gene and were proven to be genetically identical organisms by pulsed field gel electrophoresis. Both patients were managed with well-humidified and heated oxygen using a venturi mask and ventilator to promote excretion of sputum. It was thought that the medical respiratory care devices that provide a humid and warm environment, an optimal condition for proliferation of C. violaceum, can contribute to C. violaceum infection in a hospital environment.

Clinical characteristics of Ochrobactrum anthropi bacteremia.

The clinical picture of Ochrobactrum anthropi infection is not well described because the infection is rare in humans and identification of the pathogen is difficult. We present a case of O. anthropi bacteremia that was initially misidentified as Ralstonia paucula and later identified by 16S rRNA sequencing and recA analysis.

Delftia acidovorans bacteremia caused by bacterial translocation after organophosphorus poisoning in an immunocompetent adult patient.

A 46-year-old woman was transferred to our emergency unit because of impaired consciousness and respiratory failure with the history of excessive pesticide intake. The patient was hypersalivative and had bilateral pupillary miosis. Laboratory results showed markedly decreased cholinesterase. She was intubated and treated in the intensive care unit with the diagnosis of organophosphorus poisoning. The patient had persisted diarrhea, with a high fever and stomach tenderness on day 10. Whole-body contrast enhanced computed tomography revealed a swollen, enhanced small intestinal wall, and blood culture identified Delftia acidovorans. She was diagnosed as D. acidovorans bacteremia, probably caused by bacterial translocation based on the clinical presentation and the exclusion of other sources, and treated well with a total of 8 days of antibiotic therapy. So far as we know, this is the first case of D. acidovorans bacteremia that was presumably caused by bacterial translocation after organophosphorus poisoning in an immunocompetent adult patient.

Co-infection with invasive pulmonary aspergillosis and Pneumocystis jirovecii pneumonia after corticosteroid therapy.

A 95-year-old man with chronic obstructive pulmonary disease and chronic hepatitis C virus infection was treated for acute lung injury caused by Chlamydophila pneumoniae with antibiotics and high-dose corticosteroids. In total, 7,500 mg methylprednisolone and 680 mg prednisolone were administered over 21 days. However, respiratory failure progressed, and chest computed tomography (CT) scan showed bilateral ground-glass opacity and cavity-forming consolidation in the right upper lobe. Despite intensive therapy, the patient died of multiple organ failure on day 7. CT-guided necropsy was performed, and pathological examination revealed invasive pulmonary aspergillosis and Pneumocystis jirovecii pneumonia. Invasive pulmonary aspergillosis and P. jirovecii pneumonia are both life-threatening opportunistic fungal infections. Co-infection of these organisms is rare but possible if the patient is in an extremely immunocompromised state. Short-term but high-dose systemic corticosteroid therapy was considered to be the risk factor in this case. We should pay more attention to immunocompromised hosts who might be suffering from co-infection of opportunistic infections. Moreover, we need to consider preventive measures in such high-risk cases.

Emergence of Daptomycin-Resistant Staphylococcus aureus during Treatment.

A 68-year-old man with persistent bacteremia accompanying a large iliopsoas abscess, vertebral osteomyelitis, discitis and central venous port infection caused by methicillin-resistant Staphylococcus aureus (MRSA) was admitted to our hospital. During the course of treatment, the emergence of a daptomycin (DAP)-resistant MRSA strain was confirmed; the minimum inhibitory concentration was 1 to 2 µg/mL for vancomycin and more than 1 µg/mL for DAP. Although the bacterial cell wall was not significantly thickened, an increased positive surface charge and single-nucleotide polymorphism within mprF have been confirmed in DAP-resistant strains. Still rare, but clinicians need to be cautious of the emergence of DAP-resistant MRSA during treatment.

Pyogenic Spondylitis and Diskitis Caused by Helicobacter cinaedi in an Immunocompetent Adult Patient.

We herein describe the first reported case of pyogenic spondylitis and diskitis caused by Helicobacter cinaedi. The results of magnetic resonance imaging and the histology of biopsied tissue were suggestive of acute infection at the lumbar spine. The pathogen was obtained by a blood culture examination and identified by 16S rRNA analysis. Eight weeks of antibiotics therapy resulted in a good clinical course. H. cinaedi infections have been increasingly reported in recent years, but the pathogen's epidemiological and pathological characteristics are still unclear. One of the difficulties in understanding the pathogenesis of H. cinaedi has been the challenges in cultivating the pathogen. Novel strategies for the diagnosis of H. cinaedi must be developed.

Emergence of third-generation cephalosporin-resistant Enterobacteriacae in a Japanese critical care setting.

AIM: Extended-spectrum beta-lactamases and AmpC beta-lactamases give resistance to Enterobacteriaceae against cephalosporins, which are important drugs in various clinical settings. Within 5 days, a total of eight strains of Citrobacter freundii and two strains of Escherichia coli, all of which were resistant to third-generation cephalosporins, were isolated from six different patients in a critical care center. We carried out epidemiological and genetic studies to confirm the situation to be an outbreak by a single strain or a beta-lactamase-producing gene. METHODS: A review of patients' clinical data, pulsed-field gel electrophoresis epidemiological study against the strains, and polymerase chain reaction analysis for the detection of extended-spectrum beta-lactamase genes (TEM, SHV, CTX-M-1, CTX-M-2, and CTX-M-9) and multiplex polymerase chain reaction analysis for plasmid-mediated AmpC-beta-lactamase genes were carried out. RESULTS: Pulsed-field gel electrophoresis showed none of the subjects were genetically identical organisms. However, all strains possessed either extended-spectrum beta-lactamases (TEM, CTX-M-2, and CTX-M-9) or AmpC-beta-lactamases. One patient carried both extended-spectrum beta-lactamase- and AmpC- beta-lactamase-producing organisms. CONCLUSION: This study revealed that various types of easily transmittable drug resistance genes exist in the critical care setting concurrently. This case was not an outbreak of such strains, but the present situation might indicate a more serious condition than a mere outbreak of a single resistant strain. Enterobacteriaceae that possess extended-spectrum beta-lactamases or AmpC-beta-lactamases are increasingly common in many medical institutions in Japan, and constitutive monitoring of drug-resistant organisms and proper contact precautions are essential to prevent possible outbreaks.

Is wet swab superior to dry swab as an intranasal screening test?

Methicillin-resistant Staphylococcus aureus is still a great concern, and recognition of the carrier is essential for appropriate infection control in intensive care units. The utility of wet swab compared to dry swab as an intranasal screening test has not been well assessed yet. A comparative study of the wet and dry swab in its ability to detect the organism was performed against critically ill patients, and it was found that there were no statistically significant differences between the two different methods. The wet swab did not show increased sensitivity compared to dry one.

Severe soft tissue infection of the lower extremity caused by Haemophilus influenzae (serotype f, biotype II) in an adult patient.

The infection caused by non-b-type Haemophilus influenzae has been increasing in this Hib (H.influenzae serotype b) vaccination era. H.influenzae serotype f (Hif) is considered as one of those emerging pathogens. In general, H.influenzae is a common pathogen of such as pneumonia, otitis media, and meningitis, but is rare in soft tissue infection, especially at the extremity. We report a rare case of severe soft tissue infection caused by Hif which occurred at the lower extremity of immunocompetent adult patient.