Gordonia araii Infection Associated with an Orthopedic Device and Review of the Literature on Medical Device-Associated Gordonia Infections

Gordonia infections in humans are rare and usually affect immunocompromised patients. We present the first case of Gordonia araii infection associated with a medical device in an immunocompetent patient. Sequencing was required for conclusive identification. We compared our case to the 16 Gordonia species-associated medical device infections reported to date.     

Species-Level Identification of Actinomyces Isolates Causing Invasive Infections: Multiyear Comparison of Vitek MS (Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry) to Partial Sequencing of the 16S rRNA Gene

Actinomyces species are uncommon but important causes of invasive infections. The ability of our regional clinical microbiology laboratory to report species-level identification of Actinomyces relied on molecular identification by partial sequencing of the 16S ribosomal gene prior to the implementation of the Vitek MS (matrix-assisted laser desorption ionization–time of flight mass spectrometry [MALDI-TOF MS]) system. We compared the use of the Vitek MS to that of 16S rRNA gene sequencing for reliable species-level identification of invasive infections caused by Actinomyces spp. because limited data had been published for this important genera. A total of 115 cases of Actinomyces spp., either alone or as part of a polymicrobial infection, were diagnosed between 2011 and 2014. Actinomyces spp. were considered the principal pathogen in bloodstream infections (n = 17, 15%), in skin and soft tissue abscesses (n = 25, 22%), and in pulmonary (n = 26, 23%), bone (n = 27, 23%), intraabdominal (n = 16, 14%), and central nervous system (n = 4, 3%) infections. Compared to sequencing and identification from the SmartGene Integrated Database Network System (IDNS), Vitek MS identified 47/115 (41%) isolates to the correct species and 10 (9%) isolates to the correct genus. However, the Vitek MS was unable to provide identification for 43 (37%) isolates while 15 (13%) had discordant results. Phylogenetic analyses of the 16S rRNA sequences demonstrate high diversity in recovered Actinomyces spp. and provide additional information to compare/confirm discordant identifications between MALDI-TOF and 16S rRNA gene sequences. This study highlights the diversity of clinically relevant Actinomyces spp. and provides an important typing comparison. Based on our analysis, 16S rRNA gene sequencing should be used to rapidly identify Actinomyces spp. until MALDI-TOF databases are optimized.     

Gordonia Bacteremia

Gordonia species are ubiquitous aerobic actinomycetes that rarely cause infection in humans. We report the second known case of Gordonia otitidis catheter-related bacteremia in an immunocompromised patient and review four additional cases of Gordonia bacteremia seen at our institution over the past 14 years. In addition, the existing literature on Gordonia infections is reviewed.     

Speciation and susceptibility of Nocardia isolated from ocular infections

Twenty Nocardia spp. isolated from ocular infections were identified by 16S rRNA gene sequencing and susceptibility was determined using the E-test (AB Biodisk, Sweden). Species distribution among the 20 isolates was as follows: Nocardia levis (n = 7), Nocardia farcinica (n = 3), Nocardia abscessus (n = 2), Nocardia brasiliensis (n = 2), Nocardia amamiensis (n = 2), Nocardia puris (n = 1), Nocardia beijingensis (n = 1), Nocardia otitidiscaviarum (n = 1) and Nocardia thailandica (n = 1). All isolates were sensitive to amikacin. Eighteen (90%) isolates were sensitive to tobramycin, 11 (55%) to ciprofloxacin and gatifloxacin, and seven (35%) to azithromycin and clarithromycin. Molecular methods are useful for the identification and for the detection of Nocardia species that have not so far been reported in human infections.     

Yeast Identification Algorithm Based on Use of the Vitek MS System Selectively Supplemented with Ribosomal DNA Sequencing: Proposal of a Reference Assay for Invasive Fungal Surveillance Programs in China

Sequence analysis of the internal transcribed spacer (ITS) region was employed as the gold standard method for yeast identification in the China Hospital Invasive Fungal Surveillance Net (CHIF-NET). It has subsequently been found that matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) is potentially a more practical approach for this purpose. In the present study, the performance of the Vitek MS v2.0 system for the identification of yeast isolates collected from patients with invasive fungal infections in the 2011 CHIF-NET was evaluated. A total of 1,243 isolates representing 31 yeast species were analyzed, and the identification results by the Vitek MS v2.0 system were compared to those obtained by ITS sequence analysis. By the Vitek MS v2.0 system, 96.7% (n = 1,202) of the isolates were correctly assigned to the species level and 0.2% (n = 2) of the isolates were identified to the genus level, while 2.4% (n = 30) and 0.7% (n = 9) of the isolates were unidentified and misidentified, respectively. After retesting of the unidentified and misidentified strains, 97.3% (n = 1,209) of the isolates were correctly identified to the species level. Based on these results, a testing algorithm that combines the use of the Vitek MS system with selected supplementary ribosomal DNA (rDNA) sequencing was developed and validated for yeast identification purposes. By employing this algorithm, 99.7% (1,240/1,243) of the study isolates were accurately identified with the exception of two isolates of Candida fermentati and one isolate of Cryptococcus gattii. In conclusion, the proposed identification algorithm could be practically implemented in strategic programs of fungal infection surveillance.     

Clinical and microbiological features of bacteraemia with Gram-positive anaerobic cocci: a population-based retrospective study

ObjectivesGram-positive, anaerobic cocci (GPAC) can cause infections in humans. Only a few cases of bacteraemia with GPAC have been reported. We describe the clinical and microbiological characteristics of GPAC bacteraemia.MethodsA retrospective population-based study of GPAC bacteraemia 2012–2016 in southern Sweden was performed. GPAC were identified using matrix-associated laser desorption ionization time-of-flight mass spectrometry or 16S rRNA gene sequencing. Etests were used to determine antibiotic susceptibilities. Data on patient and infection characteristics, treatment, and outcome were collected from the medical records.ResultsA total of 226 episodes of GPAC bacteraemia in adults were studied; this corresponds to an annual incidence of 3.4 cases per 100,000 persons per year. The bacteria identified were Anaerococcus spp. (n = 43), Atopobium spp. (n = 7), Blautia spp. (n = 1), Finegoldia spp. (n = 15), Parvimonas spp. (n = 100), Peptoniphilus spp. (n = 52), Peptostreptococcus spp. (n = 2), and Ruminococcus spp. (n = 9) of which 200 isolates were identified to the species level. Resistance to imipenem and piperacillin was not identified, whereas resistance among the 229 isolates to penicillin was detected in four, to metronidazole in six, and clindamycin in 16 isolates. The median age of patients was 73 years (55–83, IQR), 57% were male and comorbidities were common. Fifty-one per cent of infections were polymicrobial. In 60% of cases a focus of infection was identified. Forty per cent of patients had either organ dysfunction or shock. The 30-day mortality was 11%, and nosocomial infections were over-represented among the deceased.ConclusionsGPAC bacteraemia is much more common than previously reported. GPAC-bacteraemia is a condition with significant mortality mainly affecting elderly persons with comorbidities.     

Bacteraemia caused by Weissella confusa at a university hospital in Taiwan, 1997–2007

Human infections caused by Weissella confusa are rarely reported. Ten patients with bacteraemia caused by W. confusa who were treated at a tertiary-care hospital in Taiwan during 1997–2007 were studied. All isolates were initially misidentified as various Lactobacillus and Leuconostoc species by two commercial automated identification methods, and were confirmed to be W. confusa by 16S rRNA sequencing analysis. MICs of these isolates for ten antimicrobial agents were determined by the agar dilution method. The characteristics of these patients included underlying malignancy (n = 4), presence of a central catheter (n = 6), surgery within the previous 3 months (n = 4) and concomitant polymicrobial bacteraemia (n = 5, 50%). Mortality was directly attributed to bacteraemia in two patients. All isolates exhibited high trimethoprim–sulphamethoxazole and ceftazidime MICs (≥128 mg/L) and were inhibited by linezolid, daptomycin, ceftobiprole and tigecycline at 4, 0.12, 2 and 0.12 mg/L, respectively. In conclusion, W. confusa should be included in the list of organisms causing bacteraemia in immunocompromised hosts. Novel antibiotics, including daptomycin, moxifloxacin, doripenem and tigecycline, exert good activity against W. confusa.     

Dual Invasive Infection with Phaeoacremonium parasiticum and Paraconiothyrium cyclothyrioides in a Renal Transplant Recipient: Case Report and Comprehensive Review of the Literature of Phaeoacremonium Phaeohyphomycosis

Despite increasing reports of human infection, data about the optimal care of Phaeoacremonium infections are missing. We report a case of an infection due to Phaeoacremonium parasiticum and Paraconiothyrium cyclothyrioides, initially localized to skin and soft tissue, in a kidney transplant patient. Despite surgical drainage and excision of the lesion and combination antifungal therapy with voriconazole and liposomal amphotericin B, a disseminated infection involving the lungs and brain developed and led to death. We performed a systematic literature review to assess the general features and outcome of human infections due to Phaeoacremonium species. Thirty-six articles were selected, and 42 patients, including ours, were reviewed. Thirty-one patients (74%) were immunocompromised because of organ or bone marrow transplantation (n = 17), diabetes or glucose intolerance (n = 10), rheumatoid arthritis or Still''s disease (n = 4), chronic hematological diseases (n = 3), or chronic granulomatous disease (n = 3). Ten patients (24%) reported initial cutaneous trauma. Skin and soft tissue infections represented 57% of infections (n = 24), and disseminated infections, all occurring in immunocompromised patients, represented 14% of infections (n = 6). The main antifungal drugs used were azoles (n = 41) and amphotericin B (n = 16). Surgical excision or drainage was performed in 64% of cases (n = 27). The cure rate was 67% (n = 28). There were 10% cases of treatment failure or partial response (n = 4), 19% relapses (n = 8), and 7% losses to follow-up (n = 3). The death rate was 19% (n = 8). Management of Phaeoacremonium infections is complex because of slow laboratory identification and limited clinical data, and treatment relies on a combination of surgery and systemic antifungal therapy.     

Gordonia Species as Emerging Causes of Continuous-Ambulatory-Peritoneal-Dialysis-Related Peritonitis Identified by 16S rRNA and secA1 Gene Sequencing and Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry (MALDI-TOF MS)

We report here four cases of continuous ambulatory peritoneal dialysis-related peritonitis caused by three different species of Gordonia. The portal of entry was likely through Tenckhoff catheters. 16S rRNA and secA1 gene sequencing are so far the most reliable methods for the accurate identification of Gordonia species.     

Bloodstream infections due to Peptoniphilus spp.: report of 15 cases

Peptoniphilus spp. are Gram-positive anaerobic cocci (GPAC) that were formerly classified in the genus Peptostreptococcus. This study describes 15 cases of Peptoniphilus spp. bloodstream infection (BSI) diagnosed from 2007 to 2011 using 16S rDNA sequencing in patients with pneumonia, pre-term delivery, soft tissue infection or colon or bladder disease. Seven out of 15 (47%) of these cases had polymicrobial BSIs. One of the isolates was closely related to P. duerdenii (EU526290), while the other 14 isolates were most closely related to a Peptoniphilus sp. reference strain (ATCC 29743) and P. hareii (Y07839). Peptoniphilus is a rare but important cause of BSI.     

Clinical and microbiological characteristics of Nocardiosis including those caused by emerging Nocardia species in Taiwan, 1998–2008

The genus of Nocardia is rapidly expanding and the species distribution varies with different geographical locations. We retrospectively reviewed the laboratory records of the bacteriology laboratory at National Taiwan University Hospital from January 1998 to June 2008 to identify patients with nocardiosis. During the study period, 164 isolates of Nocardia spp. were identified from 134 patients but only 113 patients had Nocardia infection. Nocardia brasiliensis (n = 54) was the most common pathogen, followed by N. asteroides (n = 36), N. farcinica (n = 7), N. flavorosea (n = 4), N. otitidiscaviarum (n = 3), N. nova (n = 3), N. beijingensis (n = 2) and one each of N. puris, N. jinanensis and N. takedensis. The major types of infection were cutaneous infection (56.6%), pulmonary infection (33.6%) and disseminated infection (7.1%). Eighty-eight patients received sulfonamide-containing antibiotic and eight of 100 patients with available data on outcomes died during the episode of nocardiosis. In conclusion, the clinical and microbiological manifestations of Nocardiosis vary with the different Nocardia species. Accurate identification of the species is crucial to make the diagnosis.     

In vitro activity of the novel siderophore cephalosporin,cefiderocol, in Gram-negative pathogens in Europe by site of infection

ObjectivesWe assessed the activity of the novel siderophore cephalosporin, cefiderocol and selected other antibacterial agents against Gram-negative bacterial isolates in Europe.MethodsIsolates were obtained between 2013 and 2018 from European countries participating in the SIDERO-WT and SIDERO-Proteeae multinational surveillance studies. Isolates were categorised by infection site, focusing on bloodstream infections, hospital-acquired/ventilator-associated bacterial pneumonia (HABP/VABP), complicated intra-abdominal infections and complicated urinary tract infections. Cefiderocol activity was compared with ceftazidime–avibactam, ceftolozane–tazobactam, colistin and meropenem using standard susceptibility testing methods. European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints were used to interpret susceptibility data.ResultsIsolates (n = 20 911) were collected from 145 sites in 24 countries in Europe, the highest proportion (34%) being from patients with HABP/VABP. Enterobacterales (66.6% of isolates) were more frequent than glucose non-fermenting species (33.4%) overall, with some differences between infection sites. Across all infection sites, the MIC₅₀/MIC₉₀ for cefiderocol was ≤0.5/≤2 mg/L for Enterobacter spp., ≤0.25/<2 mg/L for Klebsiella spp., 0.12/2 mg/L for Acinetobacter spp., ≤0.25/1 mg/L for Pseudomonas aeruginosa and ≤0.12/≤0.5 mg/L for Stenotrophomonas maltophilia. Across all infection sites, cefiderocol MICs were ≤2 mg/L for ≥96% of Enterobacter spp., ≥95% of Klebsiella spp., ≥90% of Acinetobacter spp. and ≥99% of Pseudomonas aeruginosa and Stenotrophomonas maltophilia isolates. Cefiderocol maintained high activity in carbapenem-resistant isolates, and the difference in activity between carbapenem-resistant (percentage susceptibility at EUCAST breakpoint: E. coli 77.8%, Klebsiella spp. 69.2%, Pseudomonas aeruginosa 97.5%, Acinetobacter spp. 90.7%, Stenotrophomonas maltophilia 99.6%) and carbapenem-susceptible (percentage susceptibility at EUCAST breakpoint: E. coli 99.4%, Klebsiella spp. 98.0%, Pseudomonas aeruginosa 99.7%, Acinetobacter spp. 94.9%) isolates was lower for cefiderocol than other agents.ConclusionsCefiderocol had excellent activity against all Gram-negative species, independent of key infection site and carbapenem MIC. Cefiderocol is a useful addition to the therapeutic options available for these difficult-to-treat infections.     

Molecular identification and antifungal susceptibility of 75 clinical isolates of Trichophyton spp. from southern Brazil

BackgroundDermatophytoses affect more than 20% of the world's population and is caused by filamentous fungi, mainly of the genus Trichophyton. The species identification through microscopic direct examination and culture methods is challenging, with molecular presenting high sensitivity and specificity. Although there are several therapy options for dermatophyte infections, treatment failures and antifungal resistance are growing concerns.ObjectiveThis study aimed to identify clinical isolates of Trichophyton spp. from southern Brazil using molecular methods and determine their in-vitro antifungal susceptibility.Material and MethodsSeventy-five isolates were identified through sequencing of the ITS region. The exposure to seven antifungals drugs was performed according to protocol M28-A2 of the Clinical and Laboratory Standards Institute (CLSI).ResultsSixty-one isolates (81%) were identified as T. interdigitale, which differs from the epidemiological data present in the literature. Thirteen isolates were identified as T. rubrum and one as T. tonsurans. Terbinafine was the most effective antifungal, followed by itraconazole and voriconazole, which is in accordance with the results reported in previous studies.ConclusionsThe use of molecular methods to identify Trichophyton spp. clinical isolates and the performance of susceptibility tests are relevant to epidemiological data, identification of the emergence of antifungal resistance, and to help to translate the in-vitro antifungal susceptibility results into clinical practice.     

Identification of Polybacterial Communities in Patients with Postoperative,Posttraumatic, and Endogenous Endophthalmitis through 16S rRNA Gene Libraries

Endophthalmitis is a potential vision-threatening complication following surgical procedures (postoperative endophthalmitis [POE]), trauma (posttraumatic endophthalmitis [PTE]), and bacteremic seeding of the eye from a distant infection site (endogenous endophthalmitis [EE]). Several studies have revealed the polybacterial characteristics of endophthalmitis, which make the administration of antibiotics to treat the disease challenging. However, until now, the polybacterial communities of POE, PTE, and EE have not been precisely studied. Hence, the present study was designed to identify the bacterial community of endophthalmitis through 16S rRNA gene libraries. Of the 40 intraocular samples tested, 30 libraries were constructed with bacterial nested-PCR-positive samples. The obtained recombinant clones were screened through amplified rRNA gene restriction analysis (ARDRA) to identify unique clones. The multiple types of ARDRA patterns (P = 0.345) and diverse bacterial sequences (P = 0.277) within the libraries revealed the polybacterial nature of infection in POE, PTE, and EE. Moreover, to the best of our knowledge, this is the first report on polybacterial infection in EE. Gram-positive bacteria, including Bacillus spp. (n = 19), Streptococcus spp. (n = 18), Staphylococcus spp. (n = 6), Exiguobacterium spp. (n = 3), Gemella spp. (n = 2), Enterococcus spp. (n = 2), a Lysinibacillus sp. (n = 1), a Clostridium sp. (n = 1), and a Nocardia sp. (n = 1), and Gram-negative bacteria, including Serratia spp. (n = 18), Pseudomonas spp. (n = 10), Enterobacter spp. (n = 8), Acinetobacter spp. (n = 3), Pantoea spp. (n = 3), a Haemophilus sp. (n = 1), and a Massilia sp. (n = 1), were identified. Interestingly, among them, 10 bacterial species were not previously reported to be associated with endophthalmitis or other ocular infections. Besides, the presence of 4 unidentifiable clones suggests the possibility of novel organisms that might cause eye infections. Therefore, it is recommended that, in addition to the polybacterial nature of POE, PTE, and EE infections, the spectrum of the pathogenic bacterial community identified in this work should be considered while administering antibiotic therapy in suspected endophthalmitis cases.     

Detection and Molecular Typing of Campylobacter Isolates from Human and Animal Faeces in Coastal Belt of Odisha,India

Introduction: Campylobacter-mediated diarrhoea is one of the major causes of gastroenteritis globally. A majority of the Campylobacter spp. that cause disease in humans have been isolated from animals. Faecal contamination of food and water is the identified frequent cause of human campylobacteriosis. Methodology: In the present study, faecal samples from patients with symptoms of acute diarrhoea (n = 310) and domestic animals including cows (n = 60), sheep (n = 45) and goats (n = 45) were collected from the same localities in the peri-urban Bhubaneswar city. Genomic DNA isolation followed by polymerase chain reaction and sequencing was employed to analyse Campylobacter spp.-positive samples. Results: Of the 460 faecal samples, 16.77% of human samples and 25.33% of animal samples were found to be positive for Campylobacter spp. Among animals, the isolation rate was highest in sheep followed by cows and goats with 9.33%, 8.66% and 7.33%, respectively. The highest number of Campylobacter-positive cases was diagnosed in infants of 2–5 years age. Concurrent infection of other pathogens in addition to Campylobacter spp. was frequently detected in the samples. Conclusion: The present study showed the incidence of Campylobacter infections in human and different animal species in and around Bhubaneswar, Odisha. The analysis suggested that domestic animals can be the potential sources for human campylobacteriosis in the region.     

<Emphasis Type="Italic">Streptococcus pneumoniae</Emphasis> skin and soft tissue infections: characterization of causative strains and clinical illness

Streptococcus pneumoniae is an uncommon cause of skin and soft tissue infections, yet the incidence and clinical significance of its isolation in samples of skin or soft tissues in unselected hospital samples is poorly understood. In the present study, a review was conducted of the records of all patients with skin and soft tissue infections due to S. pneumoniae at a university hospital between January 1994 and December 2005. The isolates were identified by standard methods and were serotyped, and susceptibility testing was performed by the broth microdilution method following the guidelines of the Clinical and Laboratory Standards Institute. During the study period, 3,201 isolates of S. pneumoniae were recovered from several sources. Of these, 69 (2.2%) were from skin and soft tissue samples (69 patients). Complete information could not be obtained for 13 patients. Of the 56 patients remaining, 36 (64.3%) were infected and fulfilled the inclusion criteria. The following types of infections were observed: surgical wound infection (n = 11), burn infection (n = 7), pyomyositis (n = 6), cellulitis (n = 4), perineal or scrotal abscess (n = 3), and other (n = 5). Thirty-one (86%) patients had a favorable outcome, and 5 (13.8%) patients died. Mortality was directly attributable to S. pneumoniae infection in three of the five fatal cases. Of the 39 S. pneumoniae isolates obtained (36 from skin and soft tissues, three from blood cultures), 58.9% were penicillin nonsusceptible, 7.7% were cefotaxime nonsusceptible, and 20.5% were erythromycin resistant. The most frequent serotypes were 3, 19, 11, and 23. Of the overall number of isolates of S. pneumoniae recovered in a general institution, 2.2% involved skin and soft tissues (of which 64% were clinically significant). Mortality due to pneumococcal skin and soft tissue infections was low. R. Pallarés, coordinator (e-mail: rpallares@bell.ub.es)     

Streptococcus pneumoniae ocular infections,prominent role of unencapsulated isolates in conjunctivitis

The aim of this study was to determine the characteristics and shifts in serotype distribution of pneumococcal isolates causing ocular infections in a region of northern Spain in two periods: 1999–2010 for episodes of conjunctivitis (n = 612) and 1980–2010 for uncommon and more severe non-conjunctival ocular infections (n = 36). All isolates were serotyped and non-typeable isolates were confirmed as unencapsulated by multiplex-PCR of the lytA, ply and cpsA genes. Genotyping was done by pulsed-field gel electrophoresis and multi-locus sequence typing. Most conjunctivitis cases occurred in children under 5 years old (89.5%), and more severe non-conjunctival ocular infections occurred in patients older than 25 years (86.1%). Unencapsulated isolates were detected in 213 conjunctivitis episodes (34.8%) and one non-conjunctival infection (2.8%). Rates of unencapsulated isolates were similar throughout the study. Among 399 conjunctival encapsulated isolates, the most prevalent were serotypes 19A (n = 53), 15B (n = 30), 6A (n = 27), 19F (n = 25), 23F (n = 21) and 6B (n = 17). The most prevalent serotypes in non-conjunctival infections were serotype 3 (n = 4), 23F (n = 4), 6B (n = 3) and 19A (n = 3). Conjunctivitis caused by serotypes included in the hepta-valent pneumococcal conjugate vaccine steadily decreased, accounting for 34.9% (22/63) in 1999–2001, 19.7% (23/117) in 2002–04, 13.6% (33/242) in 2005–07 and 3.2% (6/190) in 2008–10. Among the 213 unencapsulated isolates, 31 different pulsed-field gel electrophoresis patterns were identified. The main clonal complexes (CC) were CC941 (ST941, ST942), CC448 (ST448) and CC344 (ST344, ST3097). CC941 was the predominant CC in 1999–2001, 2002–04 and 2005–07, being replaced by CC448 in 2008–10. The multidrug-resistant CC344 was present throughout the study.     

Antimicrobial Treatment Options for Granulomatous Mastitis Caused by Corynebacterium Species

Corynebacterium species are increasingly recognized as important pathogens in granulomatous mastitis. Currently, there are no published treatment protocols for Corynebacterium breast infections. This study describes antimicrobial treatment options in the context of other management strategies used for granulomatous mastitis. Corynebacterium spp. isolated from breast tissue and aspirate samples stored from 2002 to 2013 were identified and determined to the species level using matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS), 16S RNA sequencing, and rpoB gene targets. The MICs for 12 antimicrobials were performed using Etest for each isolate. Correlations of these with antimicrobial characteristics, choice of antimicrobial, and disease outcome were evaluated. Corynebacterium spp. from breast tissue and aspirate samples were confirmed in 17 isolates from 16 patients. Based on EUCAST breakpoints, Corynebacterium kroppenstedtii isolates (n = 11) were susceptible to seven antibiotic classes but resistant to β-lactam antibiotics. Corynebacterium tuberculostearicum isolates (n = 4) were multidrug resistant. Two nonlipophilic species were isolated, Corynebacterium glucuronolyticum and Corynebacterium freneyi, both of which have various susceptibilities to antimicrobial agents. Short-course antimicrobial therapy was common (median, 6 courses per subject; range, 1 to 9 courses). Patients with C. kroppenstedtii presented with a hot painful breast mass and underwent multiple surgical procedures (median, 4 procedures; range, 2 to 6 procedures). The management of Corynebacterium breast infections requires a multidisciplinary approach and includes culture and appropriate sensitivity testing to guide antimicrobial therapy. Established infections have a poor outcome, possibly because adequate concentrations of some drugs will be difficult to achieve in lipophilic granulomata. Lipophilic antimicrobial therapy may offer a therapeutic advantage. The role of immunotherapy has not been defined.     

Mixed Infections and Rifampin Heteroresistance among Mycobacterium tuberculosis Clinical Isolates

Mixed infections and heteroresistance of Mycobacterium tuberculosis contribute to the difficulty of diagnosis, treatment, and control of tuberculosis. However, there is still no proper solution for these issues. This study aimed to investigate the potential relationship between mixed infections and heteroresistance and to determine the high-risk groups related to these factors. A total of 499 resistant and susceptible isolates were subjected to spoligotyping and 24-locus variable-number tandem repeat methods to analyze their genotypic lineages and the occurrence of mixed infections. Two hundred ninety-two randomly selected isolates were sequenced on their rpoB gene to examine mutations and heteroresistance. The results showed that 12 patients had mixed infections, and the corresponding isolates belonged to Manu2 (n = 8), Beijing (n = 2), T (n = 1), and unknown (n = 1) lineages. Manu2 was found to be significantly associated with mixed infections (odds ratio, 47.72; confidence interval, 9.68 to 235.23; P < 0.01). Four isolates (1.37%) were confirmed to be heteroresistant, which was caused by mixed infections in three (75%) isolates; these belonged to Manu2. Additionally, 3.8% of the rifampin-resistant isolates showing no mutation in the rpoB gene were significantly associated with mixed infections (χ², 56.78; P < 0.01). This study revealed for the first time that Manu2 was the predominant group in the cases of mixed infections, and this might be the main reason for heteroresistance and a possible mechanism for isolates without any mutation in the rpoB gene to become rifampin resistant. Further studies should focus on this lineage to clarify its relevance to mixed infections.     

Frequency of Isolation of Pathogens from Bloodstream, Nosocomial Pneumonia, Skin and Soft Tissue, and Urinary Tract Infections Occurring in European Patients

 The frequency of isolation of pathogens that cause different types of infections is an important guide for empiric therapy. As part of the SENTRY Antimicrobial Surveillance Program, the frequency of isolation of different bacterial species from bloodstream, nosocomial pneumonia, skin and soft tissue, and urinary tract infections occurring in European patients was determined. A total of 15,704 isolates were collected in 1997 and 1998 from 24 university hospitals in 14 European countries: 9,194 from bloodstream, 2,052 from nosocomial pneumonia, 2,320 from skin and soft tissue, and 2,138 from urinary tract infections. More than 95% of all bacterial infections were caused by only 15 different genera. Staphylococcus spp. and Escherichia spp. accounted for more than 50% of the infectious isolates, with the exception of those obtained from cases of nosocomial pneumonia. In the latter type of infection, isolates belonging to these two genera were responsible for 30% of the infections. An analysis at the individual species level showed that Escherichia coli caused a large proportion of bloodstream and urinary tract infections (20.8% and 49.3% of isolates, respectively). Staphylococcus aureus was the main causative species for nosocomial pneumonia and skin and soft tissue infections (21.5% and 37.4% of isolates, respectively). In addition, Pseudomonas aeruginosa played an important role in all types of infection analyzed.