Necrotizing soft-tissue infections and sepsis caused by Vibrio vulnificus compared with those caused by Aeromonas species

Imaging of necrotizing fasciitis

Necrotizing Fasciitis (NF) is a rare, but highly lethal, rapidly progressive necrotic infection of the soft-tissue fascia. More common in immunocompromised patients, NF typically affects the extremities, perineal area, genital area (Fournier gangrene), and less commonly the torso. Although classically a clinical diagnosis, imaging is a powerful adjunct to facilitate early diagnosis in equivocal cases. The key features of NF of radiography, ultrasound, CT, and MRI are reviewed, as are the inherent limitations of NF diagnosis for each modality. With a high level of sensitivity, specificity, and soft tissue contrast, MRI remains the gold standard imaging method for evaluation of NF.

Current diagnosis and management of necrotizing soft tissue infections: What you need to know

ABSTRACT

Necrotizing soft tissue infections are rare bacterial infections of the skin and soft tissues with a high morbidity and mortality rate, requiring prompt diagnosis and surgical intervention. These represent a spectrum of disease resulting in tissue necrosis that is rapidly progressive; however, they remain a diagnostic challenge because the average surgeon or emergency medicine provider may only see one or two over the course of their career. Diagnosis is largely clinical and based on subtle physical examination findings, physiologic instability, and laboratory derangements. Aids to diagnosis such as scoring systems and cross-sectional imaging may be used; however, the findings are not specific, so management should not be based on these alone. The most common cause of necrotizing soft tissue infection is polymicrobial infection; however, specific bacteria such as clostridial species, group A streptococcal, methicillin resistant Staphylococcus aureus , and aquatic bacteria may also be causative. Initial management includes broad spectrum antibiotics, fluid resuscitation for severe sepsis, and early aggressive surgical debridement. Often, these patients require multiple operative debridement to achieve source control, and a low threshold for repeat debridement should be maintained because these infections can progress rapidly. Once source control is achieved, patients may be left with extensive wounds requiring multidisciplinary care and wound management. Necrotizing infections have long been viewed based on mortality outcomes alone because of their rarity and severity. Over recent years, more reports have shown a decrease in the mortality rates from those previously reported, allowing for a focus on methods to improve morbidity of these infections.

The Impact of Cefuroxime Susceptibility on Aeromonas Necrotizing Fasciitis Outcomes

Despite aggressive antibiotic therapy and surgical debridement, Aeromonas necrotizing fasciitis (NF) can lead to high amputation and mortality rates. Our study compares the different antibiotic minimum inhibitory concentrations (MICs) via Epsilometer tests (E-tests) between non-survivors and survivors of Aeromonas NF of limbs. A prospective review of 16 patients with Aeromonas NF was conducted for 3.5 years in a tertiary coastal hospital. E-tests were conducted for 15 antimicrobial agents to determine the MIC value for Aeromonas species. These patients were divided into non-survival and survival groups. The clinical outcomes, demographics, comorbidities, presenting signs and symptoms, laboratory findings, and microbiological results between the two periods were compared. A total of four patients died, whereas 12 survived, resulting in a 25% mortality rate. A higher proportion of bloodstream infections (100% vs. 41.7%; p = 0.042), monomicrobial infections (100% vs. 33.3%; p = 0.021), shock (100% vs. 33.3%; p = 0.021), serous bullae (50% vs. 0%; p = 0.009), liver cirrhosis (100% vs. 25%; p = 0.009), chronic kidney disease (100% vs. 33.3%; p = 0.021), lower susceptibility to cefuroxime (25% vs. 83.3%; p = 0.028), and ineffective antibiotic prescriptions (75% vs. 16.7%; p = 0.029) was observed in non-survivors. Aeromonas NF is an extremely rare skin and soft-tissue infection that is associated with high mortality, bacteremia, antibiotic resistance, and polymicrobial infection. Therefore, antibiotic regimen selection is rendered very challenging. To improve clinical outcomes and irrational antimicrobial usage, experienced microbiologists can help physicians identify specific pathogens and test MIC.

A fatal case of Aeromonas jandaei necrotizing fasciitis

Introduction

Necrotizing soft tissue infections (NSTIs) are associated with a fulminating course because of their rapid destruction of tissue planes underlying the skin. Aeromonas -associated monomicrobial NSTIs are usually associated with exposure to fresh water, particularly among agricultural workers and fish handlers. Albeit uncommon in incidence, urgent medical and surgical intervention are required once a diagnosis has been made.

Case report

A 40-year-old male patient, a known case of alcoholic liver disease, presented to the emergency department with pain and diffuse swelling of bilateral lower limbs, which quickly progressed to form blackish discolouration and blebs. Blood for preliminary haematological and biochemical investigations, as well as fluid draining from blebs, were sent for microbiological investigation. The Gram stain revealed occasional neutrophils and Gram-negative bacilli, and pure growth in aerobic culture was identified as Aeromonas jandaei by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The patient was started on empirical antimicrobials, although lesions continued to progress and he ultimately succumbed within 12 h of hospital admission.

Conclusion

As appropriate antimicrobial therapy and early surgical intervention are required for management of the same, occupational exposure and the fulminant course should raise suspicion of Aeromonas -associated infections.

Rational Use of Antibiotics and Education Improved Aeromonas Necrotizing Fasciitis Outcomes in Taiwan: A 19-Year Experience

BACKGROUND

Aeromonas necrotizing fasciitis (NF) causes high rates of amputation and mortality, even after aggressive surgical debridement and antibacterial therapy. This study investigated the effects of rational use of antibiotics and education by infectious disease (ID) physicians on Aeromonas NF treatment outcomes.

METHODS

Retrospective review for conducted for four years (period I, without an ID physician, December 2001 to December 2005) and 15 years (period II, with an ID physician, January 2006 to March 2021). In period II, the hospital-wide computerized antimicrobial approval system (HCAAS) was also implemented. A pretest-posttest time series analysis compared the two periods. Differences in clinical outcomes, demographics, comorbidities, signs and symptoms, laboratory findings, Aeromonas antibiotic susceptibility, and antibiotic regimens were compared between the two periods.

RESULTS

There were 19 patients in period I and 53 patients in period II. Patients had a lower rate of amputation or mortality in period II (35.8%) compared with period I (63.2%). Forty-four patients (61.1%) had polymicrobial infections. In the emergency room, the rate of misdiagnosis decreased from 47.4% in period I to 28.3% in period II, while effective empiric antibiotic usage increased from 21.1% in period I to 66.0% in period II. After the ID physician's adjustment, 69.4% received monotherapy in period II compared to 33.3% in period I.

CONCLUSIONS

Because Aeromonas NF had a high mortality rate and was often polymicrobial, choosing an antibiotic regimen was difficult. Using the HCAAS by an experienced ID physician can improve rational antibiotic usage and clinical outcomes in Aeromonas NF.

Vibrio vulnificus necrotizing fasciitis with sepsis presenting with pain in the lower legs in winter: a case report

Background

Vibrio vulnificus infections develop rapidly and are associated with a high mortality rate. The rates of diagnosis and treatment are directly associated with mortality.

Case presentation

We describe an unusual case of a 61-year-old male patient with chronic liver disease and diabetes who presented with a chief complaint of pain in both lower legs due to V. vulnificus infection in winter. Within 12 h of arrival, typical skin lesions appeared, and the patient rapidly developed primary sepsis. Despite prompt appropriate antibiotic and surgical treatment, the patient died 16 days after admission.

Conclusion

Our case findings suggest that V. vulnificus infection should be suspected in patients with an unclear infection status experiencing pain of unknown origin in the lower legs, particularly in patients with liver disease or diabetes, immunocompromised status, and alcoholism.

Opportunistic Pathogens of Recreational Waters with Emphasis on Antimicrobial Resistance-A Possible Subject of Human Health Concern

Infections caused by exposure to opportunistic pathogens can cause serious health problems during recreational water use. The problem of diseases caused by microbes transmitted by water is a major public health challenge, especially in developing countries with economic problems and poor hygiene conditions. Moreover, the quality of water in natural reservoirs is often at a very low level in terms of microbiological water purity, which means that their use for recreational purposes, but also as a source of drinking water, may have serious health consequences. Recreational waters pose a threat to human health. Therefore, the quality of recreational waters is closely monitored in many jurisdictions. In this review, we summarize key information on the most common pathogens that can be water-based or waterborne. The issue of antimicrobial resistance among opportunistic pathogens remains equally important. It is important not only to fight pathogens, but also to take action to reduce chemical stressors (especially antibiotics) in the aquatic environment, and to understand the various mechanisms of the spread of antibiotic-resistant genes.

In-hospital mortality associated with necrotizing soft tissue infection due to Vibrio vulnificus: a matched-pair cohort study

Background

It remains unclear whether Vibrio vulnificus necrotizing soft tissue infection (NSTI) is associated with higher mortality compared with non-Vibrio NSTI. This study’s objective was to compare outcomes including in-hospital mortality and prognosis between patients with V. vulnificus NSTI and those with non-Vibrio NSTI.

Method

A retrospective 1:2 matched-pair cohort study of hospitalized patients with NSTI diagnosed by surgical finding was conducted in two tertiary hospitals in southern Taiwan between January 2015 and January 2020. In-hospital outcomes (mortality, length of stay) were compared between patients with and without V. vulnificus infection. We performed multiple imputation using chained equations followed by multivariable regression analyses fitted with generalized estimating equations to account for clustering within matched pairs. All-cause in-hospital mortality and length of stay during hospitalization were compared for NSTI patients with and without V. vulnificus.

Result

A total of 135 patients were included, 45 in V. vulnificus NSTI group and 90 in non-Vibrio group. The V. vulnificus NSTI patients had higher mortality and longer hospital stays. Multivariable logistic regression analysis revealed that V. vulnificus NSTI was significantly associated with higher in-hospital mortality compared with non-Vibrio NSTI (adjusted odds ratio = 1.52; 95% confidence interval 1.36–1.70; p < 0.01).

Conclusion

Vibrio vulnificus NSTI was associated with higher in-hospital mortality and longer hospital stay which may increase health care costs, suggesting that preventing V. vulnificus infection is essential.

Comparison of Surgical Outcomes and Predictors in Patients with Monomicrobial Necrotizing Fasciitis and Sepsis Caused by Vibrio vulnificus, Aeromonas hydrophila, and Aeromonas sobria

Background: Monomicrobial necrotizing fasciitis caused by Vibrio vulnificus, Aeromonas hydrophila, and Aeromonas sobria are often associated with high mortality rates. The purpose of this study was to compare the independent predictors related to outcomes between Vibrio vulnificus and Aeromonas species necrotizing fasciitis. Patients and Methods: Monomicrobial necrotizing fasciitis caused by Vibrio vulnificus (60 patients) and Aeromonas species (31 patients) over an 11-year period were reviewed retrospectively. Differences in mortality, patient characteristics, clinical presentations, and laboratory data were compared between the Vibrio vulnificus and Aeromonas species groups, and between the death and the survival subgroups of patients with Aeromonas species. Results: Six patients in the Vibrio vulnificus group (10%) and 11 in the Aeromonas species group (32.3%) died. Fifty-nine patents had bacteremia and 16 patients died (27.1%). Patients who had Vibrio vulnificus had a higher incidence of bacteremia. The patients who had Aeromonas species presenting with bacteremia were significantly associated with death. The death subgroup of patients with Aeromonas necrotizing fasciitis had a higher incidence of bacteremia, higher counts of banded leukocytes, lower platelet counts, lower total lymphocyte counts, and lower serum albumin level than the survival subgroup. Conclusions: Monomicrobial necrotizing fasciitis caused by Aeromonas species was characterized by more fulminating and higher mortality than that of Vibrio vulnificus, even after early fasciotomy and third-generation cephalosporin antibiotic therapy. Those risk factors, such as bacteremia, shock, lower platelet counts, lower albumin levels, and antibiotic resistance were associated with mortality, which should alert clinicians to pay more attention to and aggressively treat those patients with Aeromonas and Vibrio necrotizing fasciitis.

WSES/GAIS/WSIS/SIS-E/AAST global clinical pathways for patients with skin and soft tissue infections

Skin and soft-tissue infections (SSTIs) encompass a variety of pathological conditions that involve the skin and underlying subcutaneous tissue, fascia, or muscle, ranging from simple superficial infections to severe necrotizing infections.Together, the World Society of Emergency Surgery, the Global Alliance for Infections in Surgery, the Surgical Infection Society-Europe, The World Surgical Infection Society, and the American Association for the Surgery of Trauma have jointly completed an international multi-society document to promote global standards of care in SSTIs guiding clinicians by describing reasonable approaches to the management of SSTIs.An extensive non-systematic review was conducted using the PubMed and MEDLINE databases, limited to the English language. The resulting evidence was shared by an international task force with different clinical backgrounds.

Different types of bullae of limbs with necrotizing fasciitis predict different outcome: a prospective study

Study objective

Necrotizing fasciitis (NF) is an uncommon life-threatening necrotizing skin and soft tissue infection. Bullae are special skin manifestations of NF. This study was conducted to analyze the differences between different types of bullae of limbs with NF for providing the information to emergency treatment.

Methods

From April 2015 to August 2018, patients were initially enrolled based on surgical confirmation of limbs with NF. According to the presence of different bullae types, patients were divided into no bullae group (Group N), serous-filled bullae group (Group S), and hemorrhagic bullae group (Group H). Data such as demographics, clinical outcomes, microbiological results, presenting symptoms/signs, and laboratory findings were compared among these groups.

Results

In total, 187 patients were collected, with 111 (59.4%) patients in Group N, 35 (18.7%) in Group S, and 41 (21.9%) in Group H. Group H had the highest incidence of amputation, required intensive care unit care, and most patients infected with Vibrio species. In Group N, more patients were infected with Staphylococcus spp. than Group H. In Group S, more patients were infected with β-hemolytic Streptococcus than Group H. Patients with bacteremia, shock, skin necrosis, anemia, and longer prothrombin time constituted higher proportions in Group H and S than in Group N.

Conclusions

In southern Taiwan, patients with NF accompanied by hemorrhagic bullae appear to have more bacteremia, Vibrio infection, septic shock, and risk for amputation. If the physicians at the emergency department can detect for the early signs of NF as soon as possible, and more patient’s life and limbs may be saved.

Predictors for gram-negative monomicrobial necrotizing fasciitis in southern Taiwan

BACKGROUND

Necrotizing fasciitis (NF) is a rare and life-threatening necrotizing skin and soft-tissue infection. Infectious pathogens of NF must be detected early and treated rapidly to prevent loss of limb or a fatal outcome. This study aimed to detect more reliable predictors between gram-negative and gram-positive monomicrobial NF of limbs.

METHODS

A total of 100 patients with limb monomicrobial NF were diagnosed prospectively from April 2015 to July 2018. These monomicrobial NF pathogens can be divided into gram-negative and gram-positive groups according to the result of Gram staining and final bacterial reports. Data such as demographics, seawater or seafood contact history, infectious location, comorbidities, presenting signs and symptoms, and laboratory findings were recorded and compared.

RESULTS

A total of 55 patients were infected with gram-negative organisms and 45 patients with gram-positive organisms. Among the 55 cases of monomicrobial gram-negative NF, 48 (87.3%) were caused mainly by Vibrio spp. (38, 69.1%) and Aeromonas spp. (10, 18.2%). A higher incidence of chronic kidney disease, cerebrovascular accident, tachypnea, and septic shock; a higher rate of band forms of leukocytes of more than 3%, serum lactate of more than 20 mg/dL, and C-reactive protein level of less than 150 mg/dL; prolonged prothrombin time; and a lower fibrinogen level were observed in patients with gram-negative infection. In a multivariate analysis, a higher incidence of seawater or seafood contact history (odds ratio [OR]: 66.301; 95% confidence interval [CI]: 7.467-588.702), a higher rate of hyperlactatemia (OR: 7.904; 95% CI: 1.231-50.744), and a low fibrinogen level (OR: 1.013; 95% CI: 1.004-1.023) indicated gram-negative infection.

CONCLUSIONS

In southern Taiwan, NF of limbs mainly affected the lower limbs, exhibited monomicrobial infection, and was predominated by gram-negative bacteria. Gram-negative monomicrobial NF of limbs often occurred in individuals with the more seawater or seafood contact history, hyperlactatemia, and low fibrinogen levels.

Surgical intervention and customised dressings in an extremity wound caused by necrotising fasciitis: a case study

Necrotising fasciitis can result in extensive loss of soft tissue and limb function. Therefore, surgical intervention requires a balance between extensive tissue removal and saving the limb. A 56-year-old male presented with necrotising fasciitis of the upper extremity. Debridement resulted in a full-thickness wound of the forearm and upper arm, an exposed olecranon and two proximally-based skin flaps. Reconstruction required multiple debridements to optimise the wound for skin grafting and to obtain flap adherence to underlying tissues of the upper arm. Conventional dressings over the flaps proved unsuccessful. Therefore, a customised versatile dressing to address each area of the wound was developed. Negative pressure wound therapy (NPWT) was applied over the exposed muscle (no exposed bone or tendon) of the lower arm and anterior upper arm; a hydropolymer foam dressing covered the elbow region. Closed incision negative pressure wound therapy (ciNPT) was applied over the incision on the posterior upper arm. Ultimately, complete wound closure was achieved, with normal/near-normal range of motion for all joints of the affected limb. There was complete take of skin grafts on the wrist, lower arm and anterior upper arm. ciNPT was effective in holding the incision together and promoting healing of the posterior upper arm, and the hydropolymer foam dressing aided with healing and coverage of the elbow region. In this case, healing of a large, complex upper extremity wound and restored limb function were achieved following use of a combination of surgical techniques and customisation of wound therapy modalities.

Predicting Morbidity and Mortality in Patients with Lower Extremity Necrotizing Fasciitis

Objectives:

Necrotizing fasciitis (NF) is a rare but limb- and life-threatening soft-tissue infection. It is among the most challenging surgical infections faced by surgeons, and is often accompanied by severe systemic toxicity. The aim of this study was to evaluate the predictive power of serum lactate and creatinine levels for mortality and morbidity in lower extremity NF.

Methods:

A retrospective cohort analysis of 87 patients with lower extremity NF was performed to evaluate the management techniques and the amputation and survival rates according to serum lactate and creatinine levels as well as the time between the onset of symptoms and surgery.

Results:

The mean time between the onset of symptoms and surgery was 3.7 days. As the time between the onset of symptoms and surgery increased, the rate of amputation and mortality significantly increased (p<0.001). In all, 66% of the mortality in the group was seen among the 12 patients who had a serum creatinine level greater than 2 mg/dL at the time of presentation. In 12 of 14 patients (85.7%) who underwent amputation/disarticulation, the mean serum lactate level was 5.7 mmol/L (range: 5.1-8.7 mmol/L), and the mean serum creatinine level was 1.92 mg/dL (range: 1.4 to.3.3 mg/dL). The high levels of serum creatinine and lactate were found to be statistically significant in terms of predicting mortality and amputation (p<0.001).

Conclusion:

Based on the results of this study, it was determined that risk factors for mortality include age, late presentation, increased serum creatinine and lactate levels, and that these factors can predict the rate of death from NF at the time of presentation.

Diagnostic Performance of Initial Serum Albumin Level for Predicting In-Hospital Mortality among Necrotizing Fasciitis Patients

Background: Hypoalbuminemia is known to be associated with adverse outcomes in critical illness. In this study, we attempted to identify whether hypoalbuminemia on emergency department (ED) arrival is a reliable predictor for in-hospital mortality in necrotizing fasciitis (NF). patients. Method: A retrospective cohort study of hospitalized adult patients with NF was conducted in a tertiary teaching hospital in Taiwan between March 2010 and March 2018. Blood samples were collected in the ED upon arrival, and serum albumin levels were determined. We evaluated the predictive value of serum albumin level at ED presentation for in-hospital mortality. All collected data were statistically analyzed. Result: Of the 707 NF patients, 40 (5.66%) died in the hospital. The mean serum albumin level was 3.1 ± 0.9 g/dL and serum albumin levels were significantly lower in the non-survivor group than in the survivor group (2.8 ± 0.7 g/dL vs. 3.5 ± 0.8 g/dL). In the multivariable logistic regression model, albumin was significantly associated with in-hospital mortality (odds ratio (OR) 0.92, 95% confidence interval (CI) 0.88–0.96, p < 0.001). The area under-the-receiver-operating-characteristic curve (AUC) for in-hospital survival was 0.77 (95% CI 0.72–0.82) and corresponding sensitivity, specificity, positive predictive value, negative predictive value, and positive and negative likelihood ratio were 66%, 74%, 33%, 88%, 2.25, and 0.48, respectively. High sensitivity (96%) for survival was shown at albumin level of 4.0 g/dL and high specificity (91%) for mortality was shown at a level of 2.5 g/dL. Conclusion: Initial serum albumin levels strongly predicted in-hospital mortality among patients with necrotizing fasciitis. NF patients with hypoalbuminemia on ED arrival should be closely monitored for signs of deterioration and early and aggressive intervention should be considered to prevent mortality.

In-Silico Prediction and Modeling of the Quorum Sensing LuxS Protein and Inhibition of AI-2 Biosynthesis in Aeromonas hydrophila

luxS is conserved in several bacterial species, including A. hydrophila, which causes infections in prawn, fish, and shrimp, and is consequently a great risk to the aquaculture industry and public health. luxS plays a critical role in the biosynthesis of the autoinducer-2 (AI-2), which performs wide-ranging functions in bacterial communication, and especially in quorum sensing (QS). The prediction of a 3D structure of the QS-associated LuxS protein is thus essential to better understand and control A. hydrophila pathogenecity. Here, we predicted the structure of A. hydrophila LuxS and characterized it structurally and functionally with in silico methods. The predicted structure of LuxS provides a framework to develop more complete structural and functional insights and will aid the mitigation of A. hydrophila infection, and the development of novel drugs to control infections. In addition to modeling, the suitable inhibitor was identified by high through put screening (HTS) against drug like subset of ZINC database and inhibitor ((-)-Dimethyl 2,3-O-isopropylidene-l-tartrate) molecule was selected based on the best drug score. Molecular docking studies were performed to find out the best binding affinity between LuxS homologous or predicted model of LuxS protein for the ligand selection. Remarkably, this inhibitor molecule establishes agreeable interfaces with amino acid residues LYS 23, VAL 35, ILE76, and SER 90, which are found to play an essential role in inhibition mechanism. These predictions were suggesting that the proposed inhibitor molecule may be considered as drug candidates against AI-2 biosynthesis of A. hydrophila. Therefore, (-)-Dimethyl 2,3-O-isopropylidene-l-tartrate inhibitor molecule was studied to confirm its potency of AI-2 biosynthesis inhibition. The results shows that the inhibitor molecule had a better efficacy in AI-2 inhibition at 40 μM concentration, which was further validated using Western blotting at a protein expression level. The AI-2 bioluminescence assay showed that the decreased amount of AI-2 biosynthesis and downregulation of LuxS protein play an important role in the AI-2 inhibition. Lastly, these experiments were conducted with the supplementation of antibiotics via cocktail therapy of AI-2 inhibitor plus OXY antibiotics, in order to determine the possibility of novel cocktail drug treatments of A. hydrophila infection.

Illnesses Associated with Freshwater Recreation During International Travel

PURPOSE OF REVIEW

International travel, adventure travel, and eco-tourism are increasing over the past few decades. This review aims to summarize the spectrum of infections associated with recreational freshwater activities and international travel.

RECENT FINDINGS

Recreational water activities can be associated with a wide range of infections. Acute febrile illnesses due to leptospirosis and schistosomiasis are not uncommon in travelers following extensive freshwater exposure. Aeromonas and other water-associated pathogens are important to consider in a traveler presenting with a skin and soft tissue infection. Recreational water activities are often associated with diarrheal illnesses, especially in children, and the range of enteric pathogens includes bacterial pathogens such as Escherichia coli O157:H7 and Shigella species and the protozoan parasites Cryptosporidium and Giardia duodenalis. Infections due to free-living amebas though rare can lead to fulminant central nervous system infections. A diverse range of infections may be associated with freshwater exposure, and it is important that these entities are considered in a returning traveler presenting with an acute illness.

Rapid identification of pathogens responsible for necrotizing fasciitis on an integrated microfluidic system

Necrotic fasciitis (NF) is a particularly aggressive and serious infection of the fascia that can penetrate into the musculature and internal organs, resulting in death if not treated promptly. In this work, an integrated microfluidic system composed of micropumps, microvalves, and micromixers was used to automate the detection of pathogens associated with NF. The entire molecular diagnostic process, including bacteria isolation, lysis, nucleic acid amplification and optical detection steps, was enacted on this developed system. Mannose binding lectin coated magnetic beads were first used as probes to isolate all bacteria in a sample. In this work, polymerase chain reaction assays featuring primers specific to genes from each of four NF-causing bacteria (Vibrio vulnificus, Aeromonas hydrophila, and methicillin-sensitive and resistant Staphylococcus aureus) were used to rapidly and exclusively verify the presence of the respective bacterial strains, and the limits of detection were experimentally found to be 11, 1960, 14, and 11 400 colony forming units/reaction, respectively; all values reflect improvement over ones reported in literature. This integrated microfluidic chip may then be valuable in expediting diagnosis and optimizing treatment options for those with NF; such diagnostic improvements could ideally diminish the need for amputation and even reduce the morality rate associated with this life-threatening illness.

Involvement of the Arg566 residue of Aeromonas sobria serine protease in substrate specificity

Aeromonas sobria serine protease (ASP) is an extracellular serine protease secreted by the organism. Here, we identified the amino acid residue of ASP that contributes to substrate specificity by using both synthetic peptides and biological protein components. The results showed that the arginine residue at position 566 (Arg-566) of ASP, which is located in the extra occluding region of ASP close to an entrance of the catalytic cavity, is involved in the substrate specificity. A substitutional point mutation of the Arg-566 residue of ASP to Ala residue (ASP[R566A]) caused a decrease of the proteolytic efficiency for a certain substrate. In addition, ASP lost the ability to recognize the primary substrate by such a point mutation, and ASP[R566A] reacted to a wide range of synthetic substrates. It is likely that Arg-566 causes an interaction with the amino acid residue at position P3 of the substrate, which is the third amino acid residue upstream from the cleavage site. Another study using ORF2 protein, a chaperone protein of ASP, further suggested that Arg-566 could also play an important role in interaction with ORF2. We therefore conclude that the Arg-566 residue of ASP is likely responsible for the selection of substrates.

Management and Novel Adjuncts of Necrotizing Soft Tissue Infections

Necrotizing soft tissue infections (NSTI) have been recognized for millennia and continue to impose considerable burden on both patient and society in terms of morbidity, death, and the allocation of resources. With improvements in the delivery of critical care, outcomes have improved, although disease-specific therapies are lacking. The basic principles of early diagnosis, of prompt and broad antimicrobial therapy, and of aggressive debridement have remained unchanged. Clearly novel and new therapeutics are needed to combat this persistently lethal disease. This review emphasizes the pillars of NSTI management and then summarizes the contemporary evidence supporting the incorporation of novel adjuncts to the pharmacologic and operative foundations of managing this disease.

A Disease Model of Muscle Necrosis Caused by Aeromonas dhakensis Infection in Caenorhabditis elegans

A variety of bacterial infections cause muscle necrosis in humans. Caenorhabditis elegans has epidermis and bands of muscle that resemble soft-tissue structures in mammals and humans. Here, we developed a muscle necrosis model caused by Aeromonas dhakensis infection in C. elegans. Our data showed that A. dhakensis infected and killed C. elegans rapidly. Characteristic muscle damage in C. elegans induced by A. dhakensis was demonstrated in vivo. Relative expression levels of host necrosis-associated genes, asp-3, asp-4, and crt-1 increased significantly after A. dhakensis infection. The RNAi sensitive NL2099 rrf-3 (pk1426) worms with knockdown of necrosis genes of crt-1 and asp-4 by RNAi showed prolonged survival after A. dhakensis infection. Specifically knockdown of crt-1 and asp-4 by RNAi in WM118 worms, which restricted RNAi only to the muscle cells, conferred significant resistance to A. dhakensis infection. In contrast, the severity of muscle damage and toxicity produced by the A. dhakensis hemolysin-deletion mutant is attenuated. In another example, shiga-like toxin-producing enterohemorrhagic E. coli (EHEC) known to elicit toxicity to C. elegans with concomitant enteropathogenicty, did not cause muscle necrosis as A. dhakensis did. Taken together, these results show that Aeromonas infection induces muscle necrosis and rapid death of infected C. elegans, which are similar to muscle necrosis in humans, and then validate the value of the C. elegans model with A. dhakensis infection in studying Aeromonas pathogenicity.

Richter's Type of Incarcerated Obturator Hernia that Presented with a Deep Femoral Abscess: An Autopsy Case Report

Patient: Female, 89

Final Diagnosis: Obturator hernia

Symptoms: Coxalgia • femoral abscess • gait disorder

Medication: —

Clinical Procedure: —

Specialty: Surgery

Synchronous multifocal necrotizing fasciitis prognostic factors: a retrospective case series study in a single center

Purpose

No reports have been published on synchronous multifocal necrotizing fasciitis (SMNF), a multifocal presence of necrotizing fasciitis in different extremities. We evaluated the clinical characteristics and outcomes of SMNF.

Methods

Eighteen patients (14 men, 4 women; mean age: 59 years) diagnosed with SMNF of the extremities between January 2004 to December 2012 were enrolled and evaluated.

Results

Vibrio species were the most commonly (78%; n = 14) isolated; others were two cases (11%) of Aeromonas spp., one case (6%) of group A β-hemolytic streptococcus, and one case of coagulase-negative staphylococcus. SMNF was in the bilateral lower limbs (72%; n = 13), bilateral upper limbs (17%; n = 3), and one patient with one upper and one lower limb (11%). Non-surviving patients had more bilateral lower limb involvement and thrombocytopenia.

Conclusions

Most patients with SMNF were male and had bilateral lower limb and marine Gram-negative bacteria involvement. The mortality of SMNF remained extremely high in patients with involvement of bilateral lower limb and initial thrombocytopenia.

The Infectious and Noninfectious Dermatological Consequences of Flooding: A Field Manual for the Responding Provider

Meteorological data show that disastrous floods are increasingly frequent and more severe in recent years, perhaps due to climatic changes such as global warming. During and after a flood disaster, traumatic injuries, communicable diseases, chemical exposures, malnutrition, decreased access to care, and even mental health disorders dramatically increase, and many of these have dermatological manifestations. Numerous case reports document typical and atypical cutaneous infections, percutaneous trauma, immersion injuries, noninfectious contact exposures, exposure to wildlife, and exacerbation of underlying skin diseases after such disasters as the 2004 Asian tsunami, Hurricane Katrina in 2005, and the 2010 Pakistan floods. This review attempts to provide a basic field manual of sorts to providers who are engaged in care after a flooding event, with particular focus on the infectious consequences. Bacterial pathogens such as Staphylococcus and Streptococcus are still common causes of skin infections after floods, with atypical bacteria also greatly increased. Vibrio vulnificus is classically associated with exposure to saltwater or brackish water. It may present as necrotizing fasciitis with hemorrhagic bullae, and treatment consists of doxycycline or a quinolone, plus a third-generation cephalosporin and surgical debridement. Atypical mycobacterial infections typically produce indolent cutaneous infections, possibly showing sporotrichoid spread. A unique nontuberculous infection called spam has recently been identified in Satowan Pacific Islanders; combination antibiotic therapy is recommended. Aeromonas infection is typically associated with freshwater exposure and, like Vibrio infections, immunocompromised or cirrhotic patients are at highest risk for severe disease, such as necrotizing fasciitis and sepsis. Various antibiotics can be used to treat Aeromonas infections. Melioidosis is seen mainly in Southeast Asia and Australia, particularly in rice farmers, and can remain latent for many years before presenting as the host's immunocompetence wanes. It can present with a variety of skin findings or as a nonspecific febrile illness, and preferred treatment consists of ceftazidime or a carbapenem with trimethoprim/sulfamethoxazole (TMP/SMX) for 2 weeks, then continuing TMP/SMX for at least 3 months. Leptospirosis is a waterborne zoonosis that is often prevalent after heavy rains or flooding. Different forms exist, including Fort Bragg fever, which produces a distinctive erythematous papular rash on the shins. Doxycycline is often sufficient; however, volume and potassium repletion may be necessary if renal involvement exists. Chromobacterium violaceum infection may occur after open skin is exposed to stagnant or muddy water. Cultured colonies produce a unique violacein pigment, and treatment typically consists of a carbapenem. Both typical and atypical fungal infections are increased in the flooding disaster scenario, such as dermatophytosis, chromoblastomycosis, blastomycosis, and mucormycosis. Appropriate antifungals should be used. In addition, land inundated with water expands the habitat for parasites and/or vectors, thus increased vigilance for regional parasitic infections is necessary after a flood. Lastly, noninfectious consequences of a flooding disaster are also common and include miliaria, immersion foot syndromes, irritant and allergic contact dermatitis, traumatic wounds and animal bites, and arthropod assault, as well as exacerbation of existing skin conditions such as atopic dermatitis, psoriasis, and alopecia areata due to increased stress or nonavailability of daily medications.

Vibrio Vulnificus Necrotizing Fasciitis Associated with Acupuncture

Necrotizing fasciitis is a severe life-threatening infection of the deep subcutaneous tissues and fascia. Infection with Vibrio vulnificus, a halophilic Gram-negative bacillus found worldwide in warm coastal waters, can lead to severe complications, particularly among patients with chronic liver diseases. We herein present an unusual case of necrotizing fasciitis caused by V. vulnificus triggered by acupuncture needle insertion. The patient, who suffered from diabetes mellitus and nonalcoholic fatty liver disease and worked at a fish hatchery, denied any injury prior to acupuncture. This is the first ever reported case of V. vulnificus infection triggered by acupuncture needle insertion, clearly emphasizing the potential hazards of the prolonged survival of V. vulnificus on the skin. The potential infectious complications of acupuncture needle insertion are discussed.

Prognostic factors in necrotizing soft-tissue infections (NSTI): A cohort study

BACKGROUND

Necrotizing soft-tissue infection (NSTI) is uncommon but life-threatening. A recent meta-analysis estimated the overall mortality at 23.5%.

OBJECTIVE

We sought to identify risk factors associated with mortality in a cohort of patients with NSTI in a tertiary care center.

METHODS

We identified 512 patients with NSTI between 1996 and 2012 in the national hospital database Program for Medicalization of Information Systems and examined risk factors of mortality with NSTI by univariate and multivariate analysis.

RESULTS

We included 109 patients with a confirmed diagnosis of NSTI; 31 (28%) died at a median follow-up of 274 days (range 2-6135 days). On multivariate analysis, independent risk factors of mortality were age older than 75 years (hazard ratio [HR] 4.4, 95% confidence interval [CI] 1.8-10.3), multifocal NSTI (HR 5.9, 95% CI 1.9-18.5), severe peripheral vascular disease (HR 5.1, 95% CI 1.5-17.0), hospital-acquired infection (HR 3.9, 95% CI 1.4-10.7), severe sepsis (HR 7.4, 95% CI 1.7-33.1), and septic shock on hospital admission (HR 13.9, 95% CI 3.8-50.4).

LIMITATIONS

This was a retrospective cohort, which disallows a precise record of the delay between diagnosis and surgery.

CONCLUSION

Our findings for this robust cohort of patients with a definite diagnosis of NSTI could help clinicians stratify NSTI severity at clinical course onset.

Necrotizing soft tissue infection following a peripheral bypass

BACKGROUND

Necrotizing soft tissue infection (NSTI), formerly referred to as necrotizing fasciitis, is a rare but serious postoperative complication. NSTI following arterial bypass is seen only once in the literature (for a coronary artery bypass) and is not mentioned following peripheral bypass. Although surgical site infections have been studied extensively, there are limited published data on postoperative NSTI and no data for NSTI following peripheral arterial bypass.

CASE PRESENTATION

Here we present the first, to our knowledge, reported instance of an NSTI following a lower extremity peripheral bypass. Despite the continued function of the bypass, the patient became rapidly systemically ill with a focus at the surgical site. Because of prompt surgical debridement, the patient survived this severe infection, though did require an above the knee amputation to control the rapid spread of the disease. The patient, a native of American Samoa, was infected with organisms infrequently associated with NSTI, Morganella morganii and Aeromonas hydrophila. This article discusses the diagnosis and treatment of this rare postoperative complication, along with a brief review of the microbiology of the disease.

CONCLUSIONS

NSTI is a rare but lethal postoperative complication. To our knowledge, this is the first reported case of an NSTI following an arterial peripheral bypass. This patient survived because of prompt and aggressive intervention.

Monomicrobial Necrotizing Fasciitis Caused by Aeromonas hydrophila and Klebsiella pneumoniae

OBJECTIVE

To compare specific characteristics and clinical outcomes of monomicrobial necrotizing fasciitis caused by Aeromonashydrophila and Klebsiella pneumoniae.

MATERIAL AND METHODS

Cases of monomicrobial necrotizing fasciitis caused by A. hydrophila (n = 11) and K. pneumoniae (n = 7) over an 8-year period were retrospectively reviewed. Differences in mortality, patient characteristics, clinical presentations, and laboratory data were compared between the A. hydrophila and the K. pneumoniae groups.

RESULTS

The clinical signs and symptoms at the time of presentation did not differ significantly (p > 0.05) between the two groups. The A. hydrophila group had a significantly shorter interval between contact and admission (1.55 ± 0.52 vs. 5.14 ± 2.12 days, p < 0.001) and significant lower total white blood cell counts (10,245 ± 5,828 vs. 19,014 ± 11,370 cells/mm(3), p < 0.045) than the K. pneumoniae group in the emergency room. Hepatic dysfunction was associated with mortality in patients with A. hydrophila infection, while diabetes mellitus was associated with mortality in patients with K. pneumoniae infection. Overall, 5 (45.5%) patients in the A. hydrophila group and 3 (42.8%) in the K. pneumoniae group died.

CONCLUSION

The initial clinical course of A. hydrophila monomicrobial necrotizing fasciitis was characterized by more rapidly progressive disease than that of the K. pneumoniae infection. Patients with hepatic dysfunction and necrotizing fasciitis should be suspected of having A. hydrophila infection, and diabetic patients with necrotizing fasciitis should be suspected of having K. pneumoniae infection initially.

Comparison of skin and soft tissue infections caused by Vibrio and Aeromonas species

BACKGROUND

The aim of this study was to compare skin and soft tissue infections (SSTIs) caused by Vibrio and Aeromonas spp.

METHODS

Patients whose cultures yielded Vibrio or Aeromonas spp. from July 2004 to June 2010 were retrieved from the computerized database of the bacteriology laboratory at a hospital in southern Taiwan. The medical records were reviewed for all patients fulfilling the criteria of monomicrobial Vibrio or Aeromonas spp. SSTIs and the clinical characteristics were analyzed.

RESULTS

During the study period, there were 28 patients with Vibrio spp. and 26 patients with Aeromonas spp., respectively. Vibrio vulnificus (n=25) and A. hydrophila (n=14) were the most common spp. There were no significant differences in age, gender, underlying diseases between patients with Vibrio and Aeromonas SSTIs. In comparison to Aeromonas SSTIs, more patients with Vibrio SSTIs were complicated with acute respiratory failure (39.3% vs. 3.8%, p=0.002) and required intensive care unit admission (50.0% vs. 7.7%, p<0.001). Furthermore, patients with Aeromonas SSTIs had a higher likelihood of discharge alone within 30 days than Vibrio SSTIs (p=0.049). The difference in in-hospital mortality among the two groups was not statistically significant (p=0.11).

CONCLUSION

Both Aeromonas and Vibrio spp. cause SSTIs in southern Taiwan and the pathogenicity of Vibrio spp. might be higher than Aeromonas spp.

Properties of hemolysin and protease produced by Aeromonas trota

We examined the properties of exotoxins produced by Aeromonas trota (A. enteropelogenes), one of the diarrheagenic species of Aeromonadaceae. Nine of 19 A. trota isolates that grew on solid media containing erythrocytes showed hemolytic activity. However, the hemolytic activities of the culture supernatants of these hemolytic strains of A. trota were markedly lower than those of A. sobria when cultured in liquid medium, and the amount of hemolysin detected by immunoblotting using antiserum against the hemolysin produced by A. sobria was also low. A mouse intestine loop assay using living bacterial cells showed that A. trota 701 caused the significant accumulation of fluid, and antiserum against the hemolysin produced suppressed the enterotoxic action of A. trota 701. These results indicated that A. trota 701 was diarrheagenic and the hemolysin produced was the causative agent of the enterotoxic activity of A. trota. The hemolysin in A. sobria was previously shown to be secreted in a preform (inactive form) and be activated when the carboxy-terminal domain was cleaved off by proteases in the culture supernatant. Since mature hemolysin was detected in the culture supernatants of A. trota, we analyzed the extracellular protease produced by A. trota. Fifteen of 19 A. trota isolates that grew on solid media containing skim milk showed proteolytic activity. We subsequently found that most A. trota isolates possessed the serine protease gene, but not the metalloprotease gene. Therefore, we determined the nucleotide sequence of the serine protease gene and its chaperone A. trota gene. The results obtained revealed that the deduced amino acid sequences of serine protease and the chaperone were homologous to those of A. sobria with identities of 83.0% and 75.8%, respectively.

Necrotizing fasciitis caused by Aeromonas caviae

Aeromonads are rarely associated with human intestinal and extra-intestinal diseases and syndromes, ranging from relatively mild illnesses such as acute gastroenteritis to life-threatening conditions, including septicemia, necrotizing fasciitis, and myonecrosis. Among the aeromonas species known to cause human infection, Aeromonas caviae has been associated with septicemia and only one reported case of human soft tissue infection. Most of the infections due to aeromonas occur in immunocompromised patients. Herein we describe a successfully treated case of post-traumatic skin and soft-tissue infections due to A. caviae in an otherwise immunocompetent individual.

Fatal non-O1, non-O139 Vibrio cholerae septicaemia in a patient with chronic liver disease

A 49-year-old male with underlying liver disease presented with fever and signs of sepsis. Non-O1/non-O139 Vibrio cholerae was isolated from his blood culture, which was positive for the hlyA and toxR genes. We report this fatal case of non-O1/non-O139 V. cholera sepsis and review the literature on non-O1/non-O139 V. cholerae sepsis in patients with chronic liver disease.

[Necrotizing soft tissue infection of the upper limb]

Necrotizing soft tissue infections and necrotizing fasciitis are life-threatening infections affecting the hypodermis, muscular fascia, and dermis secondarily. Mortality is high, with an average of 30%. The early diagnosis of necrotizing soft tissue infection is challenging, but is key to successful management of these patients. The mainstay of therapy includes early and wide surgical debridement, antibiotics and supportive care. Adjunctive therapies may have a role, but their effectiveness remains unproven. A review of the literature allows us to highlight this multidisciplinary management.

Skin and soft-tissue infections caused by Aeromonas species

This study investigated the clinical characteristics of patients with skin and soft-tissue infections (SSTIs) due to Aeromonas species. Patients with SSTIs caused by Aeromonas species during the period from January 2009 to December 2011 were identified from a computerized database of a regional hospital in southern Taiwan. The medical records of these patients were retrospectively reviewed. A total of 129 patients with SSTIs due to Aeromonas species were identified. A. hydrophila (n = 77, 59.7 %) was the most common pathogen, followed by A. veronii biovar sobria (n = 22, 17.1 %), A. veronii biovar veronii (n = 20, 15.5 %), A. caviae (n = 9, 7.0 %), and A. schubertii (n = 1, 0.8 %). The most common isolates obtained from patients with polymicrobial infections were Klebsiella species (n = 33), followed by Enterococcus spp. (n = 24), Enterobacter spp. (n = 21), Escherichia coli (n = 17), Staphylococcus spp. (n = 17), Streptococcus spp. (n = 17), and Acinetobacter spp. (n = 15). Liver cirrhosis and concomitant bacteremia were more common among patients with monomicrobial Aeromonas SSTIs than among patients with polymicrobial SSTIs. Nine (7 %) patients required limb amputations. The in-hospital mortality rate was 1.6 %. In conclusion, Aeromonas species should be considered as important causative pathogens of SSTIs, and most infections are polymicrobial. In addition, the clinical presentation differs markedly between patients with monomicrobial and those with polymicrobial Aeromonas SSTIs.

Enterobacter asburiae and Aeromonas hydrophila: soft tissue infection requiring debridement

Enterobacter asburiae and Aeromonas hydrophila are gram-negative bacilli that have been isolated in soil and water. Enterobacter asburiae can cause an array of diseases, and exposure to A hydrophila can cause soft tissue infections, including necrotizing faciitis.A healthy-appearing 22-year-old man presented with an innocuous soft tissue injury to his leg due to an all-terrain vehicle crash. He received intravenous antibiotics and was discharged with prophylactic oral antibiotics. After the rapid onset of high fevers (102°F-103°F) <24 hours postinjury, he returned to the emergency department. Emergent surgical debridement was performed, and broad-spectrum intravenous antibiotics were started. Fevers persisted, and the patient underwent repeat extensive surgical debridement and antibiotic bead placement <30 hours after the initial surgical debridement and broad-spectrum antibiotics. Intraoperative cultures found E asburiae and A hydrophila in the wound. Following a long course of antibiotics and a skin graft, he fully recovered and had no functional deficits 1 year postoperatively.Extensive research revealed that these organisms are rare in soft tissue infections. E asburiae is opportunistic but has not been reported as a primary wound organism, and A hydrophila infections have been reported following motor vehicle crashes involving wound contamination. At presentation, it is challenging to determine rare organisms in a timely fashion; however, emergent extensive surgical intervention of an accelerated aberrant disease process should be considered to avoid catastrophic outcomes.

Soft tissue infections caused by marine bacterial pathogens: epidemiology, diagnosis, and management

Skin and soft tissue infections (SSTIs) are one of the most common infection syndromes and may be caused by a large number of microorganisms. Some principles of aquatic injuries are different than those of land-based trauma. Wounds sustained in marine environment are exposed to a milieu of bacteria rarely encountered in different settings. These include Vibrio spp., Aeromonas spp., Shewanella spp., Erysipelothrix rhusiopathiae, Mycobacterium marinum, Streptococcus iniae, and other microbes. Failure to recognize and treat these uncommon pathogens in a timely manner may result in significant morbidity or death. These infections are frequently contracted as a result of recreational swimming, fishing injuries, or seafood handling. The spectrum of manifestations is wide, varying from cases of mild cellulitis, to severe life-threatening necrotizing fasciitis requiring radical surgery, to sepsis and death. This review will focus on the epidemiology, clinical manifestations, and treatment of SSTIs caused by the most important marine pathogens.

The microbiological profile and presence of bloodstream infection influence mortality rates in necrotizing fasciitis

Introduction

Necrotizing fasciitis (NF) is a life threatening infectious disease with a high mortality rate. We carried out a microbiological characterization of the causative pathogens. We investigated the correlation of mortality in NF with bloodstream infection and with the presence of co-morbidities.

Methods

In this retrospective study, we analyzed 323 patients who presented with necrotizing fasciitis at two different institutions. Bloodstream infection (BSI) was defined as a positive blood culture result. The patients were categorized as survivors and non-survivors. Eleven clinically important variables which were statistically significant by univariate analysis were selected for multivariate regression analysis and a stepwise logistic regression model was developed to determine the association between BSI and mortality.

Results

Univariate logistic regression analysis showed that patients with hypotension, heart disease, liver disease, presence of Vibrio spp. in wound cultures, presence of fungus in wound cultures, and presence of Streptococcus group A, Aeromonas spp. or Vibrio spp. in blood cultures, had a significantly higher risk of in-hospital mortality. Our multivariate logistic regression analysis showed a higher risk of mortality in patients with pre-existing conditions like hypotension, heart disease, and liver disease. Multivariate logistic regression analysis also showed that presence of Vibrio spp in wound cultures, and presence of Streptococcus Group A in blood cultures were associated with a high risk of mortality while debridement > = 3 was associated with improved survival.

Conclusions

Mortality in patients with necrotizing fasciitis was significantly associated with the presence of Vibrio in wound cultures and Streptococcus group A in blood cultures.

Predictors of mortality in skin and soft-tissue infections caused by Vibrio vulnificus

BACKGROUND

Vibrio vulnificus infection can progress rapidly in skin or soft tissue, and it is potentially life-threatening. The purpose of the present study was to explore the predictors of mortality in patients with V. vulnificus infections of skin or soft tissue.

METHODS

The medical records of 119 consecutive patients aged > or =18 years, hospitalized for V. vulnificus infections of skin or soft tissue between January 2000 and December 2007 were reviewed. Co-morbidities, clinical manifestations, laboratory studies, treatments, and outcomes were analyzed. Multiple logistic regression with the exact method was performed.

RESULTS

The mean age of the patients was 63.7 +/- 12.0 years. Twenty-four patients died, yielding an overall case fatality rate of 20%. Of the 24 deaths, 20 (83%) occurred within 72 h after hospital admission. Of 119 patients, 45 patients had primary septicemia, and 74 patients had wound infection. Multivariate analysis revealed that the following factors were associated with mortality: hemorrhagic bullous skin lesions/necrotizing fasciitis (p = 0.003), primary septicemia (p = 0.042), a greater organ dysfunction and/or infection score (p = 0.005), absence of leukocytosis (p = 0.0001), and hypoalbuminemia (p = 0.003). Treatment with surgical intervention plus antibiotics (p = 0.038) and surgical intervention within 24 h after admission (p = 0.017) were protective factors.

CONCLUSIONS

This study demonstrates that the presence of hemorrhagic bullous skin lesions/necrotizing fasciitis, primary septicemia, a greater severity-of-illness, absence of leukocytosis, and hypoalbuminemia were the significant risk factors for mortality in these patients. Moreover, patients treated with surgery plus antibiotics, especially those receiving a prompt surgical evaluation within 24 h after hospital admission, may have a better prognosis.

Prognostic factors and monomicrobial necrotizing fasciitis: gram-positive versus gram-negative pathogens

BACKGROUND

Monomicrobial necrotizing fasciitis is rapidly progressive and life-threatening. This study was undertaken to ascertain whether the clinical presentation and outcome for patients with this disease differ for those infected with a gram-positive as compared to gram-negative pathogen.

METHODS

Forty-six patients with monomicrobial necrotizing fasciitis were examined retrospectively from November 2002 to January 2008. All patients received adequate broad-spectrum antibiotic therapy, aggressive resuscitation, prompt radical debridement and adjuvant hyperbaric oxygen therapy. Eleven patients were infected with a gram-positive pathogen (Group 1) and 35 patients with a gram-negative pathogen (Group 2).

RESULTS

Group 2 was characterized by a higher incidence of hemorrhagic bullae and septic shock, higher APACHE II scores at 24 h post-admission, a higher rate of thrombocytopenia, and a higher prevalence of chronic liver dysfunction. Gouty arthritis was more prevalent in Group 1. For non-survivors, the incidences of chronic liver dysfunction, chronic renal failure and thrombocytopenia were higher in comparison with those for survivors. Lower level of serum albumin was also demonstrated in the non-survivors as compared to those in survivors.

CONCLUSIONS

Pre-existing chronic liver dysfunction, chronic renal failure, thrombocytopenia and hypoalbuminemia, and post-operative dependence on mechanical ventilation represent poor prognostic factors in monomicrobial necrotizing fasciitis. Patients with gram-negative monobacterial necrotizing fasciitis present with more fulminant sepsis.

Clinical outcomes and prognostic factors for patients with Vibrio vulnificus infections requiring intensive care: a 10-yr retrospective study

OBJECTIVE

Vibrio vulnificus infection is uncommon but potentially life-threatening. The aim of this study was to evaluate clinical outcomes and prognostic factors for patients with V. vulnificus infections admitted to an intensive care unit.

DESIGN

Retrospective study.

SETTING

Multidisciplinary intensive care unit in a 2300-bed teaching hospital.

PATIENTS

Eighty-five adult patients (≥ 18 yrs) with V. vulnificus infections who required intensive care were enrolled and reviewed during a 10-yr period.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Thirty-four of the 85 patients died, giving an intensive care unit mortality rate of 40%. The mean Acute Physiology and Chronic Health Evaluation II score on intensive care unit admission was 18.4 (95% confidence interval, 17.1-19.8). The most common underlying disease was hepatic disease (48%) followed by diabetes mellitus (22%). Multivariate analysis showed that risk factors for intensive care unit mortality were the presence of hemorrhagic bullous skin lesions/necrotizing fasciitis (relative risk, 2.4; 95% confidence interval, 1.3-4.5; p = .006), skin/soft tissue infections involving two or more limbs (relative risk, 2.5; 95% confidence interval, 1.1-5.7; p = .025), and higher Acute Physiology and Chronic Health Evaluation II scores on intensive care unit admission (relative risk, 1.2; 95% confidence interval, 1.1-1.3; p = .0001). In contrast, surgical treatment < 24 hrs after arrival was inversely associated with intensive care unit mortality (relative risk, 0.35; 95% confidence interval, 0.15-0.79; p = .012). In addition, the area under the receiver operating characteristic curve for Acute Physiology and Chronic Health Evaluation II for predicting intensive care unit mortality was 0.945 (95% confidence interval, 0.873-0.983; p = .0001). An optimal cutoff Acute Physiology and Chronic Health Evaluation II score of ≥ 20 had a sensitivity of 97% and a specificity of 86% with a 41.4-fold increased risk of fatality (p = .0003).

CONCLUSIONS

This study found that V. vulnificus-infected patients with hemorrhagic bullous skin lesions/necrotizing fasciitis, skin/soft tissue infections involving two or more limbs, or higher Acute Physiology and Chronic Health Evaluation II scores have high risks of intensive care unit mortality. However, patients receiving prompt surgical treatments within 24 hrs after admission have better prognoses.

Necrotizing soft tissue infections in the intensive care unit

Necrotizing soft tissue infection is a severe illness that is associated with significant morbidity and mortality. It is often caused by a wide spectrum of pathogens and is most frequently polymicrobial. Care for patients with necrotizing soft tissue infection requires a team approach with expertise from critical care, surgery, reconstructive surgery, and rehabilitation specialists. The early diagnosis of necrotizing soft tissue infection is challenging, but the keys to successful management of patients with necrotizing soft tissue infection are early recognition and complete surgical debridement. Early initiation of appropriate broad-spectrum antibiotic therapy must take into consideration the potential pathogens. Critical care management components such as the initial fluid resuscitation, end-organ support, pain management, nutrition support, and wound care are all important aspects of the care of patients with necrotizing soft tissue infection. Soft tissue reconstruction should take into account both functional and cosmetic outcome.

Laboratory indicators for early detection and surgical treatment of vibrio necrotizing fasciitis

BACKGROUND

Vibrio necrotizing fasciitis is a rare and life-threatening soft tissue infection, with fulminant clinical courses and high mortality rates. However, the lack of specific disease characteristics and diagnostic tools during the initial examination may delay diagnosis.

QUESTIONS/PURPOSES

We (1) asked whether the clinical indicators could predict laboratory findings during the initial stage of Vibrio necrotizing fasciitis and (2) determined the relationships between the laboratory risk indicator for necrotizing fasciitis (LRINEC) score and the diagnosis of Vibrio infection.

METHODS

We retrospectively reviewed 70 patients with 71 episodes of Vibrio necrotizing fasciitis and sepsis. Of the 70 patients, 68 had a history of contact with seawater or raw seafood; 66 had underlying chronic diseases.

RESULTS

Eighteen patients (25.7%) died a mean 18.7 days after admission, and 52 patients survived. A systolic blood pressure of 90 mm Hg or less at the time of admission to the emergency room was associated with mortality. Patients who died had lower leukocyte counts, segmented leukocyte counts, platelet counts, and serum albumin levels compared with the patients who survived and higher counts of band forms of leukocytes. Only eight patients (11%) who survived had a LRINEC score of 6 or greater.

CONCLUSIONS

The LRINEC scoring system is not applicable when treating such a highly lethal disease. We propose that severe hypoalbuminemia, severe thrombocytopenia, and increased banded forms of leukocytes are laboratory risk indicators of necrotizing fasciitis that aid in pointing toward initiation of early surgery and predict a higher risk of death.

LEVEL OF EVIDENCE

Level III Prognostic study. See the Guidelines for Authors for complete descriptions of levels of evidence.