[New antibiotics for severe infections due to multidrug-resistant pathogens : Definitive treatment and escalation]

Multidrug-resistant pathogens often lead to treatment failure of antimicrobial regimens. After a period of imbalance between the occurrence/spread of resistance mechanisms and the development of new substances, some new substances have meanwhile been approved and many more are currently undergoing clinical testing. They are particularly effective against specific resistance mechanisms/pathogens and should be preserved for definitive treatment of an isolated pathogen. In the absence of alternatives reserve antibiotics, such as aztreonam and colistin have experienced a renaissance. They are again used in special infection scenarios and clinically tested in combination with new substances. Despite the introduction and development of new substances the building of resistance will at some time also render these (at least partially) ineffective. Therefore, their implementation must be carried out according to the antibiotic or infectious diseases stewardship.

[S2k guidelines of the PEG on calculated parenteral initial treatment of bacterial diseases in adults : Focussed summary and supplementary information on antibiotic treatment of critically ill patients]

In January 2018 the recent revision of the S2k guidelines on calculated parenteral initial treatment of bacterial diseases in adults-update 2018 (Editor: Paul Ehrlich Society for Chemotherapy, PEG) was realized. It is a helpful tool for the complex infectious disease setting in an intensive care unit. The present summary of the guidelines focuses on the topics of anti-infective agents, including new substances, pharmacokinetics and pharmacodynamics as well as on microbiology, resistance development and recommendations for calculated drug therapy in septic patients. As in past revisions the recent resistance situation and results of new clinical studies are considered and anti-infective agents are summarized in a table.

Eradication of Acinetobacter baumannii/Enterobacter cloacae complex in an open proximal tibial fracture and closed drop foot correction with a multidisciplinary approach using the Taylor Spatial Frame®: a case report

Background

Multi-drug-resistant bacteria (e.g. Carbapenem-resistant Acinetobacter baumannii, extended-spectrum betalactamase or carbapenemase-producing enterobacteriaceae) are emerging in early-onset infections. So far, there is no report describing the eradication of these bacteria in a osseous infection of an open proximal tibial fracture in combination with the hexapod technology to address both osseous consolidation and closed drop foot correction.

Case presentation

After sustaining a proximal tibial fracture (Gustilo 3B), a 41-year-old man was primarily treated with open reduction and internal fixation by a locking plate and split-thickness skin graft in the home country. At the time of admission to our hospital there was a significant anterolateral soft tissue defect covered with an already-necrotic split-thickness graft and suspicious secretion. CAT and MRI scans revealed no signs of osseous healing, intramedullary distinctive osteomyelitis, as well as a large abscess zone in the dorsal compartment. Multiple wound smears showed multi-drug-resistant bacteria: Acinetobacter baumannii (Carbapenem resistant) as well as Enterobacter cloacae complex (AmpC overexpression). After implant removal, excessive osseous and intramedullary debridements using the Reamer Irrigator Aspirator (RIA^®) as well as initial negative pressure wound therapy were performed. Colistin hand-modelled chains and sticks were applied topically as well as an adjusted systemic antibiotic scheme was applied. After repetitive surgical interventions, the smears showed bacterial eradication and the patient underwent soft tissue reconstruction with a free vascularized latissimus dorsi muscle flap. External fixation was converted to a hexapod fixator (TSF^®) to correct primary varus displacement, axial assignment and secure osseous healing. A second ring was mounted to address the fixed drop foot in a closed fashion without further intervention. At final follow-up, 12 months after trauma, the patient showed good functional recovery with osseous healing, intact soft tissue with satisfactory cosmetics and no signs of reinfection.

Conclusions

A multidisciplinary approach with orthopaedic surgeons for debridement, planning and establishing osseous and joint correction and consolidation, plastic surgeons for microvascular muscle flaps for soft tissue defect coverage as well as clinical microbiologists for the optimized anti-infective treatment is essential in these challenging rare cases.

Level of evidence

Level IV.

[Bacterial sepsis : Diagnostics and calculated antibiotic therapy]

The mortality of patients with sepsis and septic shock is still unacceptably high. An effective antibiotic treatment within 1 h of recognition of sepsis is an important target of sepsis treatment. Delays lead to an increase in mortality; therefore, structured treatment concepts form a rational foundation, taking relevant diagnostic and treatment steps into consideration. In addition to the assumed focus and individual risks of each patient, local resistance patterns and specific problem pathogens must be taken into account for selection of anti-infection treatment. Many pathophysiological alterations influence the pharmacokinetics of antibiotics during sepsis. The principle of standard dosing should be abandoned and replaced by an individual treatment approach with stronger weighting of the pharmacokinetics/pharmacodynamics (PK/PD) index of the substance groups. Although this is not yet the clinical standard, prolonged (or continuous) infusion of beta-lactam antibiotics and therapeutic drug monitoring (TDM) can help to achieve defined PK targets. Prolonged infusion is sufficient without TDM but for continuous infusion TDM is basically necessary. A further argument for individual PK/PD-oriented antibiotic approaches is the increasing number of infections due to multidrug resistant pathogens (MDR) in the intensive care unit. For effective treatment antibiotic stewardship teams (ABS team) are becoming more established. Interdisciplinary cooperation of the ABS team with infectiologists, microbiologists and clinical pharmacists leads not only to a rational administration of antibiotics but also has a positive influence on the outcome. The gold standards for pathogen detection are still culture-based detection and microbiological resistance testing for the various antibiotic groups. Despite the rapid investigation time, novel polymerase chain reaction (PCR)-based procedures for pathogen identification and resistance determination, are currently only an adjunct to routine sepsis diagnostics due to the limited number of studies, high costs and limited availability. In complicated septic courses with multiple anti-infective treatment or recurrent sepsis, PCR-based procedures can be used in addition to therapy monitoring and diagnostics. Novel antibiotics represent potent alternatives in the treatment of MDR infections. Due to the often defined spectrum of pathogens and the practically absent resistance, they are suitable for targeted treatment of severe MDR infections (therapy escalation).

[Epidemiology, Diagnosis and Treatment of Adult Patients with Nosocomial Pneumonia - Update 2017 - S3 Guideline of the German Society for Anaesthesiology and Intensive Care Medicine, the German Society for Infectious Diseases, the German Society for Hygiene and Microbiology, the German Respiratory Society and the Paul-Ehrlich-Society for Chemotherapy, the German Radiological Society and the Society for Virology]

Nosocomial pneumonia (HAP) is a frequent complication of hospital care. Most data are available on ventilator-associated pneumonia. However, infections on general wards are increasing. A central issue are infections with multidrug resistant (MDR) pathogens which are difficult to treat in the empirical setting potentially leading to inappropriate use of antimicrobial therapy.This guideline update was compiled by an interdisciplinary group on the basis of a systematic literature review. Recommendations are made according to GRADE giving guidance for the diagnosis and treatment of HAP on the basis of quality of evidence and benefit/risk ratio.This guideline has two parts. First an update on epidemiology, spectrum of pathogens and antimicrobials is provided. In the second part recommendations for the management of diagnosis and treatment are given. New recommendations with respect to imaging, diagnosis of nosocomial viral pneumonia and prolonged infusion of antibacterial drugs have been added. The statements to risk factors for infections with MDR pathogens and recommendations for monotherapy vs combination therapy have been actualised. The importance of structured deescalation concepts and limitation of treatment duration is emphasized.

[Epidemiology, diagnosis and treatment of adult patients with nosocomial pneumonia. S-3 Guideline of the German Society for Anaesthesiology and Intensive Care Medicine, the German Society for Infectious Diseases, the German Society for Hygiene and Microbiology, the German Respiratory Society and the Paul-Ehrlich-Society for Chemotherapy]

Nosocomial pneumonia (HAP) is a frequent complication of hospital care. Most data are available on ventilator-associated pneumonia. However infections on general wards are also increasing. A central issue are infections with multi drug resistant (MDR) pathogens which are difficult to treat particularly in the empirical setting potentially leading to inappropriate use of antimicrobial therapy. This guideline was compiled by an interdisciplinary group on the basis of a systematic literature review. Recommendations are made according to GRADE giving guidance for the diagnosis and therapy of HAP on the basis of quality of evidence and benefit/risk ratio. The guideline has two parts. First an update on epidemiology, spectrum of pathogens and antiinfectives is provided. In the second part recommendations for the management of diagnosis and treatment are given. Proper microbiologic work up is emphasized for knowledge of the local patterns of microbiology and drug susceptibility. Moreover this is the optimal basis for deescalation in the individual patient. The intensity of antimicrobial therapy is guided by the risk of infections with MDR. Structured deescalation concepts and strict limitation of treatment duration should lead to reduced selection pressure.

[Disseminated nocardiosis : Diagnostic challenge]

Nocardiosis is a rarely found bacterial infection in Europe which can particularly affect immunocompromized patients. Localized infections of the dermis and lungs, as well as disseminated infections can be observed. Suspicion of nocardiosis should be reported to the microbiological laboratory so that goal-directed molecular genetic techniques and extended cultivation can be implemented for identification of the causative agent. A multitude of antibiotics can be used for successful therapy but the duration of therapy must be extended over 6-12 months. The mortality of disseminated infections ranges between 15-85% depending on the underlying immune status of the patient. The polymorphic appearance of nocardiosis is described based on the case of an intensive care patient.

[Relevance of ESBL-producing pathogens for clinical surgery: diagnostics, therapy, and prevention]

BACKGROUND

Multiresistant, extended spectrum beta lactamase (ESBL)-producing pathogens are an increasing problem in daily clinical life. This paper summarizes the development of resistance as well as epidemiology, diagnostics, and treatment of ESBL-producing micro-organisms. We analyzed microbiological data collected at the Grosshadern Clinic in Germany between 1996 and 2007, in order to assess the importance of these micro-organisms to medical practice and surgical care units.

PATIENTS AND METHODS

Pathogens were isolated from 28,894 patients with Escherichia coli and 10,903 with Klebsiella pneumoniae pathogens between 1996 and 2006 and tested for ESBL production. For the year 2007 we have analyzed the complete spectrum of ESBL-producing pathogens and their distribution to different departments of the clinic. The agar diffusion test with five cephalosporins and an automated detection system (BD Phoenix) were used for screening purposes. Positive results were verified with the E- and double-disc agar diffusion tests.

RESULTS

The most important pathogens isolated from patients were E. coli and K. pneumoniae. Analysis of ESBL-producing E. coli pathogens from 1996 to 2006 showed the prevalence increasing from 0% to 4.1%. For ESBL-producing K. pneumoniae, we also found a prevalence rising from 0.3% in 1996 to 6.6% in 2006. For the year 2007 a further increase in ESBL-producing pathogens was detected, reaching 182 cases, with 118 of ESBL-producing E. coli (5.7 %) and 39 of ESBL-producing K. pneumoniae (7.4%). Of these, 24 cases with E. coli and nine with K. pneumoniae were surgery patients (20% and 23%, respectively).

CONCLUSION

The results show an increasing prevalence of ESBL-producing pathogens in hospitalized patients and in surgical departments. The resulting rise in treatment costs and patient risk require thorough knowledge of risk factors, therapy, and preventive measures.

Results of two worldwide surveys into physician awareness and perceptions of extended-spectrum β-lactamases

An omnibus survey of microbiologists (n = 400) and a survey of participants (n = 49) in the Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) programme were conducted to determine the awareness and prevalence of extended-spectrum beta-lactamases (ESBLs), and the regularity and method of screening. Of the omnibus survey participants, 69% screened regularly for ESBLs, compared with 83% of MYSTIC participants. In both surveys, ESBLs were more common in Klebsiella pneumoniae (73% and 79%, respectively) and Escherichia coli (63% and 81%, respectively) than in other bacteria. The surveys demonstrated that awareness of, and testing for, ESBLs is inconsistent.

[Prevention of meningococcal meningitis]

In Germany, the incidence of meningococcal disease is approximately 1/100,000 and has not risen during recent years. Transmission occurs by direct contact with respiratory droplets, mostly from asymptomatic carriers and less frequently from patients with meningococal disease. The incubation period can vary from 2-10 days but usually is 3-4 days. Incidence is highest in children and decreases with age. The mortality from meningococcal disease is approximately 10%. In case meningococcal meningitis is clinically suspected antibiotic treatment (in Germany with penicillin G or a cephalosporin) should not be delayed. Patients must be isolated for at least 24 hours after the institution of antibiotic therapy. For early detection of local outbreaks, public health authorities should be quickly informed of suspected cases. Persons in close contact should be treated with antimicrobial chemoprophylaxis. In addition to rifampin, ciprofloxacin or ceftriaxone can be used for chemoprophylaxis. For control of local outbreaks of serogroup C meningococcal disease, the meningococcal vaccine can be used.

Group A streptococcal toxic shock syndrome with severe necrotizing fasciitis following hysterectomy--a case report

In the last 10 years an increasing number of cases of group A streptococcal toxic shock syndrome have appeared in various clinical settings. The manifestation of this syndrome includes rapidly progressive multiorgan failure and soft-tissue necrosis. This report presents a case of streptococcal toxic shock syndrome caused by Streptococcus pyogenes with severe necrotizing fasciitis of the abdominal wall following hysterectomy. Aggressive surgical intervention with debridement of all necrotic tissue necessitated resection of the complete abdominal wall (skin, subcutaneous tissue, muscle and peritoneum). The abdominal wall defect was covered with free myocutaneous flaps and split-skin grafts. Optimal treatment, including adequate antibiotic therapy and radical surgical intervention, is an indispensable prerequisite of successful outcome.

[Generalized gas gangrene infection with rhabdomyloysis following cholecystectomy]

We report a rare case of spontaneously developing generalised gas gangrene with massive rhabdomyolysis after a cholecystectomy and drainage of a hepatic abscess. On preoperative physical examination the patient appeared severely ill and was icteric and oliguric. Laboratory evaluation showed signs of systemic inflammation, elevated lactate levels, evidence of disseminated intravascular coagulation (DIC), and increased levels of serum creatine kinase (CK) activity. Abdominal ultrasound and endoscopic retrograde cholangiography showed a gallbladder perforation and a hepatic abscess. Cholecystectomy and drainage of the abscess was performed immediately and without technical problems. After postoperative admission to the intensive care unit, the patient showed evidence of generalised myonecrosis with subcutaneous gas formation and acute renal failure. Initially, there were few other signs of systemic toxicity; the patient was not hypotensive and the pulmonary gas exchange was normal. Within hours diffuse swelling of his right leg developed with cutaneous gangrene and a compartment syndrome. After fasciectomy and extensive surgical debridement, uncontrollable bleeding due to DIC developed from the fasciectomy site, which finally required exarticulation of the leg at the hip joint. At this point, multiple organ failure including severe adult respiratory distress syndrome was present. Two days after cholecystectomy, the patient died from hypoxic cardiocirculatory failure. Clostridium perfringens was repeatedly isolated from the wounds. Besides gas gangrene, the differential diagnosis of such infections includes localised clostridial cellulitis, nonclostridial anaerobic cellulitis caused by mixed aerobes and anaerobes, and type I or type II necrotising fasciitis. Patients with systemic necrotising infections should be treated with broad-spectrum antimicrobial regimens (penicillin G, 3rd generation cephalosporins, clindamycin, and aminoglycosides). An otherwise unexplained elevation of serum CK activity in the presence of acute cholecystitis may suggest haematologic spread of an aggressive myolytic agent and the beginning of myonecrosis. This should prompt immediate surgical exploration after establishing broad-spectrum antibiotic coverage. The role of hyperbaric oxygen treatment in this situation remains to be established. If hyperbaric oxygen is to be employed, it should neither delay surgical exploration nor jeopardize the patient with the hazards of an interhospital transport.

Risk factors for systemic fungal infections in liver transplant recipients

The risk factors for systemic fungal infections were analysed retrospectively in 186 orthotopic liver transplant procedures performed in 152 patients between June 1985 and January 1993. The total incidence of systemic fungal infections was 16.5% (25/152). The incidence of disseminated candidiasis, aspergillosis, and combined candidiasis and aspergillosis was 6.5% (n = 10), 7.2% (n = 11) and 2.6% (n = 4), respectively. Mortality associated with systemic fungal infections was 80% (20 of 25 patients). There were ten cases of disseminated candidiasis, with 4 patients surviving, and 11 cases of invasive aspergillosis, with 1 patient surviving. All patients with combined systemic fungal infection died. To identify perioperative risk factors, 39 variables were used to compare patients with systemic fungal infections versus those without fungal infections. Fourteen variables were significantly associated with systemic fungal infections by univariate analysis. A consecutive logistic regression analysis revealed that the amount of fresh frozen plasma transfused due to poor initial function of the allograft and acute renal failure requiring hemofiltration were independently significant risk factors for systemic fungal infections. There was no statistical correlation between systemic fungal infections and the underlying liver disease, previous long-term corticosteroids and the postoperative immunosuppressive therapy. Risk factors identified in this study should be considered in the postoperative care of the individual liver transplant recipient. In our study a poor initial function of the hepatic allograft substantially increased the risk of systemic fungal infection.

Antibiotic prophylaxis of infectious complications with endoscopic retrograde cholangiopancreatography. A randomized controlled study

Biliary sepsis represents a major percentage of fatal complications after endoscopic retrograde cholangiopancreatography. We performed a randomized controlled study to investigate the value of antibiotic prophylaxis, and to assess the frequency and source of infectious complications associated with ERCP. Ninety-six patients who underwent 100 endoscopic retrograde cholangiopancreatographies were included in the study. Half of the patients received antibiotic prophylaxis (Cefotaxime 2 g i.v. 15 min before the procedure). Bacteremia was detected in 2% of the patients receiving antibiotic prophylaxis, as compared with 16% (p less than 0.02) in the control group. In order to determine the source of bacteremia, bile samples and irrigation fluid from the suction channel of the endo-scope were obtained for bacteriological evaluation. Several lines of evidence suggested that bacteremia associated with ERCP was essentially caused by mucosal lesions of the oropharynx. Bacteremia was asymptomatic, with the exception of two patients who subsequently developed fever, but recovered rapidly under antibiotic therapy. The frequency of cholangitis following ERCP was not significantly reduced by antibiotic prophylaxis (4% vs. 2%). Recommendations for antibiotic prophylaxis are discussed.