Ecthyma gangrenosum and ecthyma-like lesions: review article.

The generally accepted definition of ecthyma gangrenosum (EG) states that this condition is pathognomonic of Pseudomonas septicemia (Pseudomonas aeruginosa) and that it should usually be seen in immunocompromised patients, particularly those with underlying malignant disease. The cases described in the literature present a somewhat different picture. Our objective was to analyze this controversy. The review analyzes 167 cases of EG that were described in the literature from 1975 to 2014. All articles on EG cases with EG-specific tissue defect that had signs of general and/or local infection and skin necrosis were included and analyzed, whatever the etiology detected. Necrotic lesions of the skin diagnosed as EG have various microbiological etiology, can occur in immunocompetent or even healthy persons, and are not necessarily connected with septicemia. In published cases, P. aeruginosa was detected in 123 cases (73.65%); of them, there were only 72 cases (58.5%) with sepsis. Other bacterial etiology was detected in 29 cases (17.35%) and fungi were detected in 15 cases (9%). While the clinical picture of the disease and the treatment strategy remain the same, there is no need to invent two separate definitions for Pseudomonas and non-Pseudomonas cases. We suggest accepting a broader definition of EG.

Design and application of a core genome multilocus sequence typing scheme for investigation of Legionnaires' disease incidents.

Sequence-based typing (SBT) for Legionella pneumophila (Lp) has dramatically improved Legionnaires' disease (LD) cluster investigation. Microbial whole genome sequencing (WGS) is a promising modality for investigation but sequence analysis methods are neither standardised, nor agreed. We sought to develop a WGS-based typing scheme for Lp using de novo assembly and a genome-wide gene-by-gene approach (core genome multilocus sequence typing, cgMLST). We analysed 17 publicly available Lp genomes covering the whole species variation to define a core genome (1,521 gene targets) which was validated using 21 additional published genomes. The genomes of 12 Lp strains implicated in three independent cases of paediatric humidifier-associated LD were subject to cgMLST together with three 'outgroup' strains. cgMLST was able to resolve clustered strains and clearly identify related and unrelated strains. Thus, a cgMLST scheme was readily achievable and provided high-resolution analysis of Lp strains. cgMLST appears to have satisfactory discriminatory power for LD cluster analysis and is advantageous over mapping followed by single nucleotide polymorphism (SNP) calling as it is portable and easier to standardise. cgMLST thus has the potential for becoming a gold standard tool for LD investigation. Humidifiers pose an ongoing risk as vehicles for LD and should be considered in cluster investigation and control efforts.

The relationship between the new taxonomy of Streptococcus bovis and its clonality to colon cancer, endocarditis, and biliary disease.

BACKGROUND: The nomenclature of Streptococcus bovis has changed. The study aims were to examine and compare the clinical characteristics and outcomes of infections based on the new taxonomy and the genetic relatedness of strains. METHODS: Bacteremic cases from 2004 to 2010 at Assaf Harofeh Medical Center were reviewed. VITEK 2 later confirmed with polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) was used for subspecies identification. VITEK 2 later confirmed with Etests was used for minimal inhibitory concentration (MIC) testing. Repetitive extragenic palindromic polymerase chain reaction (rep-PCR) was used to determine the genetic relatedness of strains. RESULTS: Twenty-four bacteremia cases were included. The median age of patients was 81 years (range 1 day to 91 years), two were neonates, three were pregnant, and 18 were elderly (≥ 65 years of age). The Charlson's combined conditional age-related score was 8.2 ± 2.9, and 11 (58 %) patients were immunosuppressed. There were 13 patients who had S. gallolyticus subsp. pasteurianus, six had S. gallolyticus subsp. gallolyticus, four had S. infantarius subsp. coli, and one had S. infantarius subsp. infantarius. Ten of 19 non-pregnant adult patients had colon adenoma or carcinoma, three had acute biliary disease, and five had endocarditis. Two patients died in the hospital. rep-PCR revealed polyclonality. There were no significant associations between subspecies or genotypes and the various clinical characteristics or outcomes. CONCLUSION: S. bovis bacteremia is a serious disease that affects elderly immunosuppressed individuals. Infection is strongly associated with colon pathology and endocarditis, regardless of the new taxonomy or clone complex. The identification of S. bovis is of paramount importance, and microbiology laboratories should differentiate its processing from that of other S. viridans.

Humidifier-associated paediatric Legionnaires' disease, Israel, February 2012.

We report a fatal case of community-acquired Legionnaires' disease in an infant aged under six months. Epidemiological and microbiological investigations suggested that a free-standing cold water humidifier using domestic tap water contaminated with Legionella pneumophila serogroup 1 served as a vehicle for infection. These findings were corroborated by sequence-based typing (SBT). Humidifier-associated Legionnaires' disease can be prevented by appropriate control measures. This case also illustrates the emerging role of SBT in the investigation of legionellosis.

Variations in the microbiology of peritonsillar abscess.

Microbiologic studies are routinely performed in the assessment of peritonsillar abscess (PTA). Though the bacterial growth rates of PTA are expected to be uniform due to high accessibility and reasonable sterility, they demonstrate a vast range of results, which is partially explained by the differing culturing methods and incubation times. Our aim was to retrospectively examine the changing features identified in the occurrence of PTA bacterial growth rates over a period of seven years. A retrospective study was undertaken on all cases of PTA admitted from January 1996 to December 2002. Details regarding sex, age and country of birth were obtained. Population data and the maximum residue level (MRL) of antibiotics in food were collected. Bacteriologic studies were analysed for gram stain, aerobic and anaerobic culture results, and also antibiotic sensitivities, if obtained. Four hundred and fifty-seven consecutive hospitalisations due to PTA were identified; 281 patients who had 310 hospitalisations with known results of the microbiologic studies were included. The most common pathogens were Streptococcus pyogenes and Prevotella. A statistically significant escalation was seen in the anaerobic growth rate from 6.8% of cases in 1996 to 37% in 1999. A similar change, though not significant, was noticed with the polymicrobial growth rate. None of the parameters investigated showed any statistically significant influence on this tendency. These results may clarify the immense range of bacterial study results reported, suggest a change in the biologic behaviour of the studied bacteria and direct further research.

Epidemiology of bacteremia episodes in a single center: increase in Gram-negative isolates, antibiotics resistance, and patient age.

Increased resistance among isolates causing bacteremia constitutes a major challenge to medical practitioners and institutions. Variability between institutes is substantial, and requires the individual analysis of local trends. An eight-year (1997-2004) surveillance study of episodes of bacteremia was conducted in an 850-bed university hospital in central Israel. Trends of incidence, resistance, age, and mortality were analyzed. We studied 6,096 patient-unique episodes of bacteremia, of which, 2,722 (45.3%) were nosocomial and 523 (9.2%) involved children less than 18 years of age. The overall incidence of bacteremia episodes has increased over the study years by 39% and the patient mean age by 7.5 years. Gram-negative organisms accounted for 72% of hospital-acquired cases and 69% of community-acquired cases. There was a substantial increase in the incidence of nosocomial episodes, predominantly due to Gram-negative isolates, mainly Acinetobacter baumannii, Klebsiella pneumoniae, and Escherichia coli. Increased resistance to broad-spectrum antibiotics was noted among Gram-negative organisms, including quinolones (in K. pneumoniae), imipenem (A. baumannii and P. aeruginosa), piperacillin-tazobactam (K. pneumoniae), and amikacin (A. baumannii and P. aeruginosa). Increased resistance to oxacillin among coagulase-negative staphylococci was also noted. The all-cause mortality rates showed a significant rise. The patient age, intensive care unit (ICU) stay, and hospital acquisition were independently associated with mortality. We describe an increase in the incidence and resistance of Gram-negative organisms causing bacteremia and concomitant ageing of the patients with bacteremia. Similar patterns have been reported from other localities, and are of real concern.

Acinetobacter baumannii: emergence and spread in Israeli hospitals 1997-2002.

The incidence of multi-drug-resistant Acinetobacter baumannii bloodstream infections (BSIs) increased two- to four-fold in three Israeli hospitals between 1997 and 2002, accounting for 3.5-18% of all hospital-acquired BSIs. This was associated with increasing carbapenem resistance reaching 35-54%, and by a dramatic increase in carbapenem consumption. In-hospital fatality rates ranged between 47% and 58% and were significantly higher than those seen with other nosocomial Gram-negative pathogens. A. baumannii was not restricted to intensive care units, but had spread to all hospital wards. Multi-drug-resistant A. baumannii has the potential to reach endemicity in hospitals and warrants more vigorous and innovative efforts to limit its spread.

Molecular epidemiology of Legionnaires' disease in Israel.

National surveillance of Legionnaires' disease (LD) is important to inform control measures and facilitate international networking for timely reporting. This study is the first to describe the molecular epidemiology of LD in Israel. Case notifications for 2006-2011, collated through mandatory reporting, were identified and demographic, clinical and laboratory data were extracted. Unrelated clinical and environmental Legionella pneumophila strains were characterized using standard procedures, Dresden panel of monoclonal antibodies and the ESCMID Study Group for Legionella Infections (ESGLI) Sequence-Based Typing scheme. In all, 294 cases were reported (crude incidence 0.67 cases/100 000; age-standardized incidence 1/100 000). LD epidemiological trends and features largely resembled those of the EU, except for a larger proportion of nosocomial cases. Of 28 clinical and 23 environmental strains analysed, 71.4% and 21.7% were serogroup (sg) 1 and the most common immunological subgroup was OLDA/Oxford (64%). Of the clinical strains, OLDA/Oxford, ST1 was the most common (43%) followed by Allentown/France, ST40 (14%). The unusual sg 3 ST338 was found in 17.4% of environmental strains. Novel STs were detected amongst 23.5% of strains. These findings warrant further molecular investigation. Molecular epidemiology data generated from neighbouring countries newly adopting the ESGLI typing scheme for L. pneumophila contribute to understanding of regional strain diversity.

Swab cultures accurately identify bacterial pathogens in diabetic foot wounds not involving bone.

AIMS: Current clinical practice assumes swab cultures from wounds are unreliable. However, this assumption is based upon data culled only from wounds in which osteomyelitis and/or gangrene were present. This study aimed to re-evaluate the accuracy of swab cultures vs. deep tissue cultures in diabetic wounds of varying depth and severity. METHODS: A total of 60 infected diabetic foot wounds were cultured. Two specimens were taken from each wound: superficial swab before debridement and deep tissue specimen towards the end of surgical debridement. RESULTS: In 37 wounds (62%), the micro-organisms isolated from the swab specimen and those isolated from the deep tissue specimen were identical. In another 12 wounds (20%), the swab culture contained all micro-organisms isolated from the deep tissue culture, but also contained additional micro-organisms. Analysis according to the depth of the wound, demonstrated that swabs identified all micro-organisms isolated from the deep tissue specimens in 36/40 wounds (90%) that did not extend to bone as opposed to 13/20 wounds (65%) that extended to bone. CONCLUSIONS: Swab cultures are valuable in identifying pathogens in diabetic foot wounds when bone is not involved. When surgical debridement is contraindicated or delayed, swab cultures can be used to select appropriate antibiotic therapy.

Simultaneous detection of three common sexually transmitted agents by polymerase chain reaction.

OBJECTIVE: Human papillomaviruses, herpes simplex viruses, and Chlamydia trachomatis are very common infections of the genital tract. The purpose of our study was to develop a polymerase chain reaction-based assay for the simultaneous detection of these organisms from a single genital swab. STUDY DESIGN: To prove the technical feasibility of a simultaneous polymerase chain reaction assay for these organisms, a mixture of deoxyribonucleic acids extracted from cells infected by these three agents was amplified in the same tube with three different sets of primers corresponding to specific regions of the human papillomavirus genome, the herpes simplex virus 1 and 2 genomes, and the Chlamydia trachomatis plasmid, respectively. Then genital swabs from patients with suspected infection by one or more of these agents were assayed by polymerase chain reaction for the presence of herpes simplex virus, human papillomavirus, and Chlamydia trachomatis independently and simultaneously. Most of the samples were analyzed in parallel by other methods: herpes simplex virus by culture., Chlamydia trachomatis by culture and antigen staining, and human papillomavirus by the filter in situ hybridization method. RESULTS: Analysis of the polymerase chain reaction products amplified from the deoxyribonucleic acid mixture revealed three bands corresponding to the respective amplified region of each microorganism. A total of 391 genital swabs were assayed independently by polymerase chain reaction for the presence of herpes simplex virus (113 samples), human papillomavirus (200 samples), and Chlamydia trachomatis (78 genital swabs and four urethral swabs). Forty-nine were herpes simplex virus positive (47 by culture), 45 were human papillomavirus positive (43 by filter in situ hybridization), and one sample was positive for Chlamydia trachomatis, both by polymerase chain reaction and by culture. Ninety-two of the 391 samples were analyzed simultaneously by polymerase chain reaction for the presence of the three agents. The correlation between the results obtained independently and simultaneously was of the order of 100%: 29 were positive for herpes simplex virus, 16 were positive for human papillomavirus, and one was positive for Chlamydia trachomatis, in one sample we could detect both human papillomavirus and herpes simplex virus. CONCLUSIONS: The polymerase chain reaction simultaneous assay is a quick and efficient way of detecting herpes simplex virus, human papillomavirus, and Chlamydia trachomatis from a single genital swab. This method can greatly simplify the diagnostic procedures in the laboratory.