A conserved strategy to attack collagen: The activator domain in bacterial collagenases unwinds triple-helical collagen

Bacterial collagenases are important virulence factors, secreted by several pathogenic Clostridium, Bacillus, Spirochaetes, and Vibrio species. Yet, the mechanism by which these enzymes cleave collagen is not well understood. Based on biochemical and mutational studies we reveal that collagenase G (ColG) from Hathewaya histolytica recognizes and processes collagen substrates differently depending on their nature (fibrillar vs. soluble collagen); distinct dynamic interactions between the activator and peptidase domain are required based on the substrate type. Using biochemical and circular dichroism studies, we identify the presumed noncatalytic activator domain as the single-domain triple helicase that unwinds collagen locally, transiently, and reversibly.

Outcomes of collagenase Clostridium histolyticum in men with ventral curvatures: an updated series

BACKGROUND

The efficacy and safety of collagenase Clostridium histolyticum (CCH) have been demonstrated in the treatment of men with Peyronie's disease (PD); however, the pivotal clinical trials excluded men with ventral penile curvature.

AIM

The study sought to evaluate outcomes of CCH treatment in men with ventral curvatures secondary to PD.

METHODS

Men with PD treated with CCH were identified from a prospective database. Patients received up to 4 series of CCH injections using a progressively modified protocol over time. Results were compared between those with baseline ventral vs nonventral penile curvatures.

OUTCOMES

Changes in penile curvature, Peyronie's Disease Questionnaire scores, International Index of Erectile Function scores, nonstandardized assessments, and adverse events.

RESULTS

A total of 560 men with PD (85 ventral curvature, 475 nonventral curvature) were included in the analysis. Baseline median curvature was 60.0° (interquartile range, 48.8°-75.0°) in the ventral cohort and 65.0° (interquartile range, 45.0°-80.0°) in the nonventral cohort. Median change from baseline penile curvature was -25.0° in the ventral cohort vs -24.0° in the nonventral cohort (P = .08, between-group comparison), which corresponded to curvature reductions of 44.7% and 33.6%, respectively (P = .03). In the subset of patients who completed CCH treatment (ie, received 8 injections or discontinued early because of patient satisfaction with curvature reduction), median change from baseline was -35.0° in the ventral cohort vs -25.0° in the nonventral cohort (P < .05); median percent improvement was 48.3% and 37.5%, respectively (P = .11). Median change from baseline in Peyronie's Disease Questionnaire and International Index of Erectile Function domain scores and adverse events were similar between cohorts, with the exception of possibly higher hematoma rates in the nonventral group (50% vs 37%; P = .05). No urethral injuries were sustained in either cohort.

CLINICAL IMPLICATIONS

Data support the use of CCH for the treatment of ventral as well as nonventral penile curvatures in men with PD.

STRENGTHS AND LIMITATIONS

Study strengths are the inclusion of a general clinical population of men with PD, the prospective design, and the relatively large series of men with ventral curvature. Limitations include the single-center and observational nature of the study.

CONCLUSION

CCH was safe and effective in the treatment of both ventral and nonventral penile curvatures in men with PD.

Patient Insight With Collagenase Treatment for Dupuytren: A Prospective Study

PURPOSE

There appears to be controversy regarding differing patient and physician perceptions of adverse effects (AEs) in the treatment of Dupuytren disease with collagenase clostridium histolyticum (CCH). The aim of this study was to compare the number, type, and severity of AEs perceived and reported by patients and by their physician METHODS: To assess AEs following CCH injection in a standardized way, patients were given a list of predefined complications and asked to rate their severity on a 4-point Likert scale ranging from 1 (serious) to 4 (insignificant).

RESULTS

Eighty-five patients were included. Patients reported fewer AEs than their physician (mean, 1.48 vs 2.18). There was no agreement between physician- and patient-reported AEs except for skin lacerations, which showed fair agreement (κ = 0.257).

CONCLUSIONS

Patients and physicians differ in their evaluation of AEs due to CCH treatment in Dupuytren disease. A fair level of agreement was observed for skin lacerations.

CLINICAL RELEVANCE

Greater consensus is needed when defining AEs associated with CCH in the treatment of Dupuytren disease.

Comparison of Collagenase Clostridium histolyticum to Surgery for the Management of Peyronie's Disease: A Randomized Trial

PURPOSE

Since Food and Drug Administration approval of collagenase Clostridium histolyticum for Peyronie's disease, there has been significant debate regarding its role and comparable efficacy to surgery.

MATERIALS AND METHODS

A randomized, controlled trial was performed of Peyronie's disease men treated with either collagenase C histolyticum + RestoreX penile traction therapy + sildenafil or penile surgery + RestoreX penile traction therapy + sildenafil, with 3-month data presented. Primary objectives were overall satisfaction, subjective changes in erectile function, penile sensation, penile length, and changes in the International Index of Erectile Function-Erectile Function Domain score. Secondary outcomes included objective changes in length, curve, adverse events, and other standardized and nonstandardized questionnaires.

RESULTS

A total of 40 men were enrolled, with 38 (collagenase C histolyticum group = 19, surgery group = 19) completing treatment and having 3-month data available. All demographic and clinicopathological variables were similar between groups. Following treatment, 50% of men in the collagenase C histolyticum group reported being very satisfied (vs 21% in the surgery group, P = .08) and noted better subjective erectile function (100% vs 68%, P = .03) and penile length (88% vs 16%, P < .0001), lesser impacts on penile sensation (75% vs 11% no change, P < .001), and similar International Index of Erectile Function-Erectile Function Domain changes (+1.5 vs +2.5, P = .91). Objectively, men in the surgery group had greater curve improvements (84% vs 54%, P < .01) and higher rates of adverse events (50 vs 13 events, P < .001) but decreased penile length (-0.5 cm vs +1.0 cm, P < .01).

CONCLUSIONS

At 3 months posttreatment, collagenase C histolyticum + RestoreX penile traction therapy + sildenafil results in lesser curve improvements but greater penile length and fewer adverse events, including impacts on subjective erectile function and sensation, than men treated with surgery.

Significant Geographic Variation in Access to Certified Collagenase Clostridium histolyticum Injectors for Peyronie's Disease Throughout the United States

INTRODUCTION

We characterize the geographic distribution of providers trained to inject Clostridium histolyticum and identify areas with low provider availability.

METHODS

We utilized a publicly available search tool to identify clinical sites offering Clostridium histolyticum in the US The data gathered included the provider's name, specialty, address, and whether the site was considered high-volume (ie, administer ≥20 Clostridium histolyticum injections per year). Data were compared to the AUA Census.

RESULTS

In total, 2,388 clinical sites offering Clostridium histolyticum were identified. A total of 894 sites (37%) were high-volume sites. The mean number of locations offering Clostridium histolyticum per 100,000 state residents was 0.69 (SD 0.27). Georgia (1.28), Rhode Island (1.13), and Alaska (1.10) had the highest number, whereas New Mexico (0.10), Maine (0.22), and Delaware (0.30) had the lowest. The mean proportion of urologists providing Clostridium histolyticum to total urologists was 0.17 (SD 0.07). The 3 states with the highest proportion were Georgia (0.37), Alaska (0.31), and Utah (0.30), whereas New Mexico (0.03), Maine (0.05), and Vermont (0.06) had the lowest.

CONCLUSIONS

States with low numbers of clinical sites offering Clostridium histolyticum per 100,000 residents relative to other states also had a low total ratio of urologists offering Clostridium histolyticum as a treatment. There is room for urologists in these states and others to expand their practice to offer Clostridium histolyticum and improve patient access to this important nonsurgical treatment option.

Pharmacotherapies in Dupuytren Disease: Current and Novel Strategies

Dupuytren disease is a benign, progressive fibroproliferative disorder of the hands. To date, only one pharmacotherapy (clostridial collagenase) has been approved for use in Dupuytren disease. There is a great need for additional nonsurgical methods that can be used to either avoid the risks of invasive treatments or help minimize recurrence rates following treatment. A number of nonsurgical modalities have been discussed in the past and continue to appear in discussions among hand surgeons, despite highly variable and often poor or no long-term clinical data. This article reviews many of the pharmacotherapies discussed in the treatment of Dupuytren disease and novel therapies used in inflammation and fibrosis that offer potential treatment options.

Predictors of Curvature Improvement in Men with Peyronie's Disease Treated with Intralesional Collagenase Clostridium Histolyticum

INTRODUCTION

Penile curvature is the most common abnormality that is observed by men with Peyronie's disease (PD). Collagenase Clostridium histolyticum (CCH) has become a standard treatment for PD patients.

AIM

To identify predictor factors associated with improvements of penile curvature outcomes in men with PD treated with CCH.

METHODS

We retrospectively collected the data of patients with PD treated with CCH up to 8 injections divided into 4 cycles between January 2014 and July 2020. Per protocol, penile curvature was assessed at baseline, and after the second and ford CCH cycle. If after cycle 2, curvature demonstrated no improvement, or penile curvature was significantly improved and the patient was happy, no further treatment was recommended. However, if penile curvature was significantly improved and the patient remained dissatisfied, 4 cycles were completed. Three categories of response were evaluated: improvement (≥10 degrees or ≥20%, either 1 happens), unchanged (±10 degrees or ±20%) or worsened (≥10 degrees or ≥20%, either 1 happens). Logistic regression analyses were performed to evaluate predictive factors associated with penile curvature improvements.

OUTCOMES

Degrees of the curvature changes between the baseline and after the cycles of CCH.

RESULTS

A total of 114 patients underwent CCH treatment. Median age was 57 years. Median PD duration was 11 months. At baseline, mean curvature was 47 degrees, 65% had dorsal curvature, 53% mid-shaft location, and 15% calcification. After CCH treatment, the mean final curvature was 40 degrees. A total of 44% improved the curvature, 39% had no change while 17% worsened after CCH treatment. Of men who had penile curvature improvement with CCH treatment, the mean curvature decreasing in degrees and percentage were 22 degrees and 41%, respectively. Men with baseline curvature ≤ 30, 31-59, and ≥ 60 degrees, the percentage curvature improvement were 29%, 43%, and 60%, respectively. Baseline curvature was the only significant predictor of penile curvature improvement after CCH (OR 1.33, 95% CI = 1.1, 1.7).

CLINICAL IMPLICATIONS

We confirmed baseline penile curvature is the most important predictive factor, and this is the first report describing proportions of penile curvature improvement with CCH treatment.

STRENGTHS AND LIMITATIONS

This study has several strengths, including the use of validated instruments. Nonetheless, there are limitations: the retrospective nature of the study, a single institution; and modelling device was not controlled.

CONCLUSION

Penile curvature improvement was significantly more common in patients with greater baseline curvature, reaching up to 60% for patients with ≥ 60 degrees.

Discovery and Characterization of Synthesized and FDA-Approved Inhibitors of Clostridial and Bacillary Collagenases

In view of the worldwide antimicrobial resistance (AMR) threat, new bacterial targets and anti-infective agents are needed. Since important roles in bacterial pathogenesis have been demonstrated for the collagenase H and G (ColH and ColG) from Clostridium histolyticum, collagenase Q1 and A (ColQ1 and ColA) from Bacillus cereus represent attractive antivirulence targets. Furthermore, repurposing FDA-approved drugs may assist to tackle the AMR crisis and was addressed in this work. Here, we report on the discovery of two potent and chemically stable bacterial collagenase inhibitors: synthesized and FDA-approved diphosphonates and hydroxamates. Both classes showed high in vitro activity against the clostridial and bacillary collagenases. The potent diphosphonates reduced B. cereus-mediated detachment and death of cells and Galleria mellonella larvae. The hydroxamates were also tested in a similar manner; they did not have an effect in infection models. This might be due to their fast binding kinetics to bacterial collagenases.

The collagenase of the bacterium Clostridium histolyticum does not favor metastasis of breast cancer

BACKGROUND

Breast cancer is the most common malignancy among women worldwide. As survival rates increase, breast reconstruction and quality of life gain importance. Of all women undergoing breast reconstruction, approximately, 70% opt for silicone implants and 50% of those develop capsular contracture, the most prevalent long-term complication. The collagenase of the bacterium Clostridium histolyticum (CCH) showed promising results in the therapy of capsule contracture; however, its influence on residual cancer cells is unknown. The aim of this study was to investigate whether CCH-treatment negatively impacts breast cancer cells in vitro and in vivo.

METHODS

MDA-MB-231 and MCF-7 cells were used in this study. In vitro, we tested the influence of CCH on proliferation, wound healing, migration and cell cycle by MTT-assay, scratch-assay, transwell-migration-assay, and flow cytometry. In vivo, solid tumors were induced in immune-deficient mice. CCH was injected into the tumors and tumor growth and metastasis formation was monitored by caliper measurement, in vivo bioluminescence imaging and histology. Gene expression analysis was performed by microarray including 27,190 genes.

RESULTS

CCH-incubation led to a dose-dependent reduction in proliferation for both cell lines, while wound healing was reduced only in MDA-MB-231 cells. No morphological alterations were monitored in cell cycle or apoptosis. In vivo, bioluminescence imaging and histology did not show any evidence of metastasis. Although CCH led to changes in gene expression of breast cancer cells, no relevant alterations in metastasis-related genes were monitored.

CONCLUSION

CCH has no impact on tumor growth or metastasis formation in vitro and in vivo. This paves the way for first clinical trials.

Limited Fasciectomy Versus Collagenase Clostridium histolyticum for Dupuytren Contracture: A Propensity Score Matched Study of Single Digit Treatment With Minimum 5 Years of Telephone Follow-Up

PURPOSE

The purpose of this study was to compare reintervention and perceived recurrence, with minimum 5 years of telephone follow-up, after limited fasciectomy or collagenase Clostridium histolyticum (CCH) in the treatment of Dupuytren contracture affecting a single digit.

METHODS

We performed a retrospective cohort study of 48 patients with single digit treatment who underwent limited surgical fasciectomy at one hospital and 111 patients who underwent CCH treatment at a second hospital from 2010 to 2013. Patients were contacted by telephone about reintervention and perceived recurrence. Average length of telephone follow-up was 7.3 years in the CCH group and 7.4 years in the surgery group. The 2 groups were compared using 2 methods to control for potential confounding bias: (1) propensity score matching and (2) multivariable analysis accounting for potential confounders.

RESULTS

After propensity score matching, there were 44 patients in each group with similar disease and demographic characteristics. Rates of reintervention and perceived recurrence were significantly higher in the CCH group than the surgery group at a minimum of 5 years following treatment.

CONCLUSIONS

Long-term overall reintervention and perceived recurrence following treatment of Dupuytren contracture affecting a single digit were higher with CCH treatment than surgical fasciectomy when comparing groups with similar baseline characteristics. Our findings may be used to counsel patients on the durability of the outcomes of treatment when considering treatment options for Dupuytren contractures.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

The Treatment of Capsular Contracture Around Breast Implants Induced by Fractionated Irradiation: The Collagenase of the Bacterium Clostridium Histolyticum as a Novel Therapeutic Approach

BACKGROUND

Irradiation therapy limits the utilization of silicone implants for breast reconstruction due to a significant risk for capsular contracture. The injection of the collagenase of the bacterium Clostridium histolyticum (CCH) might trivialize this risk by providing a minimal-invasive treatment option by capsular contracture degradation. However, efficacy in degrading breast implant capsules induced by fractionated irradiation remains unclear.

METHODS

Twenty-four rats in three groups received miniature silicone implants in a submuscular pocket. After 3D dose calculation and treatment field definition, rats of two groups underwent fractionated radiotherapy (6 × 8 Gy) using a linear accelerator. A third group served as control. On day 120, one irradiated group received injections of 0.3 mg/ml collagenase. Administration of plain solvent solution served as control in the two other groups. Outcome parameters included CT-imaging, histology, vessel wall analysis, immunohistochemistry, chemical collagen quantification and gene expression analysis.

RESULTS

Fractioned irradiation leads to a significant increase in collagen deposition around silicone implants with higher capsule thickness and collagen density when comparing all groups. Additionally, significant alterations of collagen fiber deposition were evident. Vessel wall thickness was significantly increased after radiotherapy. The injection of collagenase led to a significant reduction of capsule thickness, collagen density and content. However, the collagenase application induced a significant overexpression of TGFβ1. No side effects were monitored.

CONCLUSIONS

The CCH proved to be a safe and effective approach to degrade capsule tissue induced by fractionated irradiation in an animal model. This may pave its way for clinical application in implant-based breast reconstruction patients.

LEVEL OF EVIDENCE

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

OPTIMAL INJECTION DEPTH FOR COLLAGENASE CLOSTRIDIUM HISTOLYTICUM DETERMINED BY ULTRASONOGRAPHY IN THE TREATMENT OF DUPUYTREN´S DISEASE

INTRODUCTION

A non-surgical procedure for the treatment of Dupuytrens disease is a palmar injection of Collagenase Clostridium Histolyticum to the recommended depth of &#8220;around 2-3 mm&#8221;. However, there is little supporting evidence from the literature to substantiate this. The aim of this study was to evaluate the &#8220;optimal depth&#8221; for injection of Collagenase Clostridium Histolyticum by ultrasonography for the treatment of Dupuytrens disease.

MATERIAL AND METHODS

A total of 43 patients were enrolled in this study. We marked the collagenase injection point on the skin above the cord before injection. We then measured the distance from the surface of the skin to the middle of the cord by ultrasonography long axis imaging and defined this as the &#8220;optimal depth&#8221;.

RESULTS

The average depth from the skin to the centre of the cord was 2.4 mm. The average distance from the surface of the skin to the proximal surface of the cord was 1.0 mm and the average thickness of the cord was 2.7 mm.

CONCLUSION

By precise measurement of individual cases utilising ultrasonography we were able to confirm that the recommendations for injection depth as provided by the supplier of Collagenase Clostridium Histolyticum (2-3 mm) were in agreement with our findings. However no objective guide was supplied as with regards to interindividual variability between patients and we suggest that the use of preliminary ultrasonography will likely provide improved outcomes.

DIFFUSION OF INJECTED COLLAGENASE CLOSTRIDIUM HISTOLYTICUM FOR DUPUYTREN´S DISEASE: AN IN-VIVO STUDY

INTRODUCTION

While injecting Clostridium Histolyticum as a non-surgical tratment for Dupuytrens disease on the palmar side of the hand the recommended depth of the needle should be &#8220;around 2 to 3 mm in depth&#8221;. The diffusion of CCH inside the soft tissues around the cord might explain the occurrence of common adverse events reported in the literature such as oedema, injection site swelling, blood blisters, skin laceration, and pain in extremity. We hypothesized that the injected Collagenase Clostridium Histolyticum does not only concentrate inside the cord but also dissipates both along the cord and into the adjacent tissues. This study investigated our hypothesis by visual intraoperative findings after injecting Povidone iodine into the cord.

MATERIAL AND METHODS

Povidone iodine  (PI)was injected into the cord on six patients with Dupuytrens contracture before an open surgical operation (partial fasciectomy). We marked three hypothetical Collagenase Clostridium Histolyticum injection points at 2 mm intervals on the skin above the cord around the metacarpo-phalangeal joint and the depth of the injection (distance from the skin surface to the middle of the cord) was measured by ultrasonography. After dispensing 0.25 ml of Povidone iodine into the three points at the measured depths, we performed careful dissection and investigated the extent of diffusion of Povidone iodine visually.

RESULTS

The injection depth averaged 2.6 mm. In all cases, the cord was homogenously stained about 10 mm along its extent centrally to the injected sites and infiltration of Povidone iodine into the subcutaneous structure and fat tissue occurred. Three cases showed diffusion into the neurovascular bundles and two cases showed infiltration underneath the cord structure.

CONCLUSIONS

This study simulated the likely diffusion outcomes of injected Collagenase Clostridium Histolyticum around the cord. This implies that even if Collagenase Clostridium Histolyticum is injected into the centre of the cord, it does not concentrate inside the cord only but also dissipates along the cord and infiltrates into the adjacent tissues with potential secondary damages.

Collagenase Clostridium histolyticum for the Treatment of Distal Interphalangeal Joint Contractures in Dupuytren Disease

PURPOSE

To explore the efficacy of injectable collagenase Clostridium histolyticum (CCH) in distal interphalangeal (DIP) joint contractures in Dupuytren disease.

METHODS

A retrospective review was conducted for patients with DIP joint contractures treated with CCH. Baseline contracture and posttreatment residual contracture were recorded. The primary end point was achievement of 0° to 5° of residual contracture 30 days postmanipulation. Recurrence and adverse events are also reported.

RESULTS

Twenty-one patients were treated with collagenase for DIP joint contractures and had a mean follow-up of 2.6 months. Seventeen of 21 patients reached the primary end point of less than 5° residual flexion contracture. Eleven of 21 patients experienced an adverse event, most commonly bruising and edema. No serious complications such as neurovascular injuries or tendon ruptures were recorded. Two patients had recurrence of disease.

CONCLUSIONS

Injection with CCH is an option for the treatment of DIP joint contractures in Dupuytren disease.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Toxic dermatitis secondary to treatment with collagenase clostridium histolyticum for Dupuytren´s disease

OBJECTIVE

Secondary effects and drug reactions relative to collagenase Clostridium histolyticum treatment for Dupuytren's contracture are frequent. In only a few cases these secondary effects are considered serious. The mechanism that produces these effects of production is not well understood.

CLINICAL REPORT

We present the case report of a woman with fifth finger interphalangeal joint treatment with generalized skin rash as a complication of collagenase Clostridium histolyticum treatment.

DISCUSSION

We discuss treatment, causes and mechanisms of this rare complication from this treatment and review the bibliography about mechanisms for the different types of immunological reactions that may occur after treatment with collagenase Clostridium histolyticum and the possibility of crossed reactions with Clostridiopeptidase A used to treat skin lacerations.

Outbreak of Clostridium histolyticum infections in injecting drug users in England and Scotland

Clostridial infections in injecting drug users in the United Kingdom are a relatively new phenomenon that came to light in 2000 when cases of serious illness and deaths due to Clostridium novyi were recorded. In the period December 2003 to April 2004, the Anaerobe Reference Laboratory received twelve referrals of an extremely rare isolate, Clostridium histolyticum, from cases of infection in injecting drug users submitted from nine different hospitals in England and Scotland. Molecular typing of these isolates by two different methods of pulsed-field gel electrophoresis and PCR ribotyping revealed they are all indistinguishable, indicating a common source of the infections, most probably a batch of heroin that was recently distributed across the UK.

Enzymatic debridement of third-degree burns on guinea pigs by Clostridium histolyticum proteinases

Webster, Marion E. (Walter Reed Army Institute of Research, Washington, D. C.), Patricia L. Altieri, David A. Conklin, Sanford Berman, Joseph P. Lowenthal, and Raymond B. Gochenour. Enzymatic debridement of third-degree burns on guinea pigs by Clostridium histolyticum proteinases. J. Bacteriol. 83:602-608. 1962.-An attempt has been made to correlate in vitro activities of Clostridium histolyticum H-4 proteinases, as measured against azocasein, azocoll, gelatin, and collagen, with their ability to debride full-thickness third-degree burns (360 C, 15 sec) on guinea pigs. The major portion of the debriding activity is tentatively identified as due to the delta-proteinase, in the absence of cysteine, and to a new proteinase contained in the same fraction in the presence of cysteine. Other proteinases produced by this strain were also capable of debriding burns. However, collagenase and the gelatinase of the 0 to 22% fraction did not appear to be essential for the debridement of these burns.Studies of the proteinases produced by this organism have suggested that at least nine and probably more proteolytic enzymes are present. The need for more highly purified proteinases, in order to determine which enzyme(s) is responsible for debridement of guinea pig burns, is evident.

FACTORS AFFECTING THE ELABORATION BY CLOSTRIDIUM HISTOLYTICUM OF PROTEINASES CAPABLE OF DEBRIDING THIRD DEGREE BURN ESCHARS ON GUINEA PIGS

Berman, Sanford (Walter Reed Army Institute of Research, Washington, D. C.), Joseph P. Lowenthal, Marion E. Webster, Patricia L. Altieri, and Raymond B. Gochenour . Factors affecting the elaboration by Clostridium histolyticum of proteinases capable of debriding third degree burn eschars on guinea pigs. J. Bacteriol. 82: 582–588. 1961.—A comparison of three strains of Clostridium histolyticum grown in two different media indicated that the H-4 strain produced the greatest yield of enzyme(s) capable of debriding third degree burn eschars on guinea pigs. Some of the nutritional and physiological factors affecting the elaboration of enzymes by this strain have been investigated. Maximal yields have been obtained after incubation for 14 to 16 hr at 30 C in a medium consisting of 5% proteose-peptone, 1.5% trypticase soy broth, and vitamins; pH 7.5. A medium consisting of 2% proteose-peptone and 2% Casamino acids yields somewhat lower enzyme titers, but has the compensating advantage of being less costly and may be more amenable to purification and concentration procedures because of its reduced precipitable nitrogen content.

LARGE SCALE PURIFICATION OF PROTEINASES FROM CLOSTRIDIUM HISTOLYTICUM FILTRATES

Conklin, David A. (Walter Reed Army Institute of Research, Washington, D. C.), Marion E. Webster, Patricia L. Altieri, Sanford Berman, Joseph P. Lowenthal, and Raymond B. Gochenour . Large scale purification of proteinases from Clostridium histolyticum filtrates. J. Bacteriol. 82: 589–594. 1961.—A method for the large scale preparation and partial purification of Clostridium histolyticum proteinases by fractional precipitation with ammonium sulfate is described. Conditions for adequate separation and purification of the δ-proteinase and the gelatinase were obtained. Collagenase, on the other hand, was found distributed in four to five fractions and little increase in purity was achieved as compared to the crude ammonium sulfate precipitates.

Effects of Clostridium Histolyticum Enzymes upon Burned and Unburned Tissues in Vitro *

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