Pathogen detection in patients with perihilar cholangiocarcinoma:Implications for targeted perioperative antibiotic therapy

Background:Cholestasis should be relieved by biliary drainage prior to major liver resection.This condition is often associated with bacterial colonization of the otherwise sterile biliary system.Cholangitis reduces the regenerative capacity of the remaining liver.Therefore,targeted antibiotic therapy is a key feature in perioperative treatment in patients with perihilar cholangiocarcinoma(pCCC).Methods:Between December 1999 and December 2017,251 pCCC patients were treated in our center.In total,115 patients underwent a microbiological analysis.In addition to the characterization of the specific microorganisms and antibiotic resistance,we analyzed subgroups according to preoperative intervention.Results:Enterococci(87/254,34%)and Enterobacteria(65/254,26%)were the most frequently detected genera.In 43%(50/115)of patients,Enterococcus faecalis was found in the bile duct sample.Enterococcus faecium(29/115)and Escherichia coli(29/115)were detected in 25%of patients.In patients with percutaneous transhepatic biliary drainage(3/8,38%)or stents(24/79,30%),Enterococcus faecium was diagnosed most frequently(P<0.05).Enterococcus faecium and Klebsiella oxytoca were significantly more frequently noted in the time period after 2012(P<0.05).With regard to fungal colonization,the focus was on various Candida strains,but these strains generally lacked resistance.Conclusions:pCCC patients exhibit specific bacterial colonization features depending on the type of preoperative biliary intervention.Specifically,targeted antibiosis should be applied in this patient cohort to minimize the risk of biliary complications after major liver resection.In our cohort,the combination of meropenem and vancomycin represents an effective perioperative medical approach.

Retrospective study of the incidence, risk factors, treatment outcomes of bacterial infections at uncommon sites in cirrhotic patients

BACKGROUND Bacterial infections(BI)negatively affect the natural course of cirrhosis.The most frequent BI are urinary tract infections(UTI),pneumonia,and spontaneousbacterial peritonitis(SBP).AIM To assess the relevance of bacterial infections beyond the commonly recognized types in patients with cirrhosis and to investigate their relationship with other clinical variables.METHODS We retrospectively analyzed patients with cirrhosis and BI treated between 2015 and 2018 at our tertiary care center.BIs were classified as typical and atypical,and clinical as well as laboratory parameters were compared between the two groups.RESULTS In a cohort of 488 patients with cirrhosis,we identified 225 typical BI(95 UTI,73 SBP,72 pulmonary infections)and 74 atypical BIs,predominantly cholangitis and soft tissue infections(21 each),followed by intra-abdominal BIs(n=9),cholecystitis(n=6),head/throat BIs(n=6),osteoarticular BIs(n=5),and endocarditis(n=3).We did not observe differences concerning age,sex,or etiology of cirrhosis in patients with typical vs atypical BI.Atypical BIs were more common in patients with more advanced cirrhosis,as evidenced by Model of End Stage Liver Disease(15.1±7.4 vs 12.9±5.1;P=0.005)and Child-Pugh scores(8.6±2.5 vs 8.0±2;P=0.05).CONCLUSION Atypical BIs in cirrhosis patients exhibit a distinct spectrum and are associated with more advanced stages of the disease.Hence,the work-up of cirrhosis patients with suspected BI requires detailed work-up to elucidate whether typical BI can be identified.

Bacteriological Profile of Infections Encountered in a Pneumology Service in a Moderate-Income Country [Pneumology Department of CHU Cocody (Côte d’Ivoire)]

Introduction: Infections represent a real public health problem aggravating the morbidity and mortality of hospitalized patients. Methods: This was a retrospective study with descriptive purposes over a period of 05 years, in the Pneumology Department of the University Hospital of Cocody. Results: The average age in our population was 42 years. We observed a male predo- minance of 64.5%, with a sex ratio of 1.8. Medical history was dominated by HIV infection (23.5%), followed by tuberculosis (15.6%). Concerning lifestyle, smoking was found in 38% of cases. Symptoms progressed chronically in 80% of cases. An infectious syndrome was found in 75% of cases. Microbial culture was positive in 42% of cases. Pseudomonas aeruginosa and Klebsiella pneumoniae were encountered in 26.4% of cases each, followed by Echerichia coli in 10.4% of cases. Klebsiella pneumoniae in the first three years topped the list, but gradually. Pseudomonas aeruginosa maintained its leadership over the last three years. Pseudomonas aeruginosa isolates expressed a resistance rate of 9.8% to ceftazidime and 8.1% to imipenem;to aztreonam (36%), ticarcillin (33.3%) and levofloxacin. These strains were susceptible to fosfomycin (100%), mero- penem (96.6%) and amikacin (96%). For isolated strains of Entero- bacteria- ceae, resistance was observed about ticarcillin (83.3%) and amoxicillin clavula- nic acid (71.2%). Streptococcaceae showed resistance to tetracycline (69.2%) and erythromycin (50%). Over the years there has been an increase in re- sistance to amoxicillin-clavulanic acid ceftriaxone. The death rate was 14%. Conclusion: The bacterial profile of infections is dominated by germs respon- sible for nosocomial infection with significant mortality.

De-escalating therapy in gastric aggressive lymphoma

The treatment of primary gastric diffuse large B-cell lymphoma(DLBCL) has changed radically over the last 10–15 years, with the abandonment of routine gastrectomy in favor of more conservative therapies. Low-level evidence suggests that consolidation radiotherapy could be avoided in patients with limited-stage DLBCL of the stomach who achieve complete remission after rituximab-CHOP combination. Small, recent prospective trials suggest that selected patients with limited-stage Helicobacter pylori(H. pylori)-positive DLBCL of the stomach and favorable prognostic factors can be managed with antibiotics alone, with excellent disease control and cure rates, keeping chemo-radiotherapy for unresponsive patients. This recommendation should equally regard patients with mucosa-associated lymphoid tissue-related or de novo DLBCL. Future studies should be focused on the establishment of reliable variables able to distinguish the best candidates for exclusive treatment with H. pylori eradication from those who need for conventional chemo-immunotherapy.

Successful endovascular treatment with long-term antibiotic therapy for infectious pseudoaneurysm due to Klebsiella pneumoniae:A case report

BACKGROUND Infectious common femoral artery pseudoaneurysm caused by Klebsiellapulmonary infection is a relatively infrequent entity but is potentially life andlimb threatening. The management of infectious pseudoaneurysm remainscontroversial.CASE SUMMARY We reported a 79-year-old man with previous Klebsiella pneumoniae pulmonaryinfection and multiple comorbidities who presented with a progressive pulsatemass at the right groin and with right lower limb pain. Computed tomographyangiography showed a 6 cm × 6 cm × 9 cm pseudoaneurysm of the right commonfemoral artery accompanied by occlusion of the right superficial femoral arteryand deep femoral artery. He underwent endovascular treatment (EVT) withstent–graft, and etiology of infectious pseudoaneurysm was confirmed. Then, 3-mo antibiotic therapy was given. One-year follow-up showed the stent–graft waspatent and complete removal of surrounding hematoma.CONCLUSION The femoral artery pseudoaneurysm can be caused by Klebsiella pneumoniaederiving from the pulmonary infection. Moreover, this unusual case highlights theuse of EVT and prolonged antibiotic therapy for infectious pseudoaneurysm.

Advances in antibiotic therapy for infection after the surgical installation of implants to treat internal fractures

To summarize the advances in antibiotic therapy for infection after the surgical installation of implants to treat internal fractures. Recent studies on antibiotic therapy for infection after the surgical installation of implants to internal fractures were reviewed and analyzed.In general, systematic antibiotics are selected based on the results of bacterial culture. The duration of antibiotic treatment lasts for no more than 4 to 6 weeks. Orally administered and intravenously injected antibiotics have similar efficacies. Orally administered antibiotics exhibit a lower incidence of complications and are less costly than intravenously injected antibiotics. In addition, the efficacy of daptomycin in the treatment of bone infection is problematic. Rifampicin or fluoroquinolone antibiotics should be jointly administered when infection with bacterial biofilms is likely to occur. Calcium sulfate is a typical topically applied antibiotic delivery vehicle that can be completely degraded, with good biocompatibility, bone conduction, and drug release. The rational, systematic, and combined topical application of antibiotics can effectively decrease the recurrence rates of infection after the surgical installation of implants to treat internal fractures and can improve the quality of life of patients.

Navigating the Third Frontier of Antimicrobial Therapy to Support Women’s Health

This paper explores one of the underappreciated reasons for lack of efficacy in certain cases of antimicrobial therapy, namely the occurrence of a non-genetic resistance to antimicrobial drugs due to a metabolic quiescence of microorganisms. This review has centered on those microorganisms of particular importance in obstetrics and gynecology and accordingly has reviewed the nature and extent of the persister phenotype in relation to infectious agents affecting women’s health. We show how the quiescent persister microbial phenotype represents the next significant issue that could compromise successful antibiotic therapy. A brief history of antimicrobial therapy is provided as context for the problem posed by the persister phenotype. This review has been focused on the current literature having relevance for physicians concerned with women’s health. The study of this phenotype has led to increasing understanding of the molecular mechanisms for this state which also provides ideas for rational development of drug candidates to interdict these organisms in human disease and explores the possibility of developing specifically targeted molecules to address persisters, research on screening botanicals, existing drugs and chemicals to discover novel approaches to the clinical consequence of microbial persisters. Of interest in this review, is the return to naturally occurring botanical substances, first to be used as anti-infectives, now being considered as possible agents to address persister microorganisms. Overall this paper aims to provide information tailored especially to the obstetrics and gynecology specialists.

Probabilistic Antibiotic Therapy in the Infectious Diseases Department of the Yalgado Ouédraogo University Hospital (CHU-YO) in Ouagadougou, Burkina Faso

Introduction: In Burkina Faso, as in most developing countries, limited access to biological tests forces practitioners to resort very often to probabilistic antibiotic therapy. The objective of this study is to determine the extent of this prescription. Patients and Methods: This was a cross-sectional study with retrospective data collection of patients hospitalized in the infectious diseases department in the period from January 1, 2005 to December 31, 2020. The records of patients who received probabilistic antibiotic therapy were included. Results: During the study period, 330 patients had received probabilistic antibiotic therapy. The majority of patients were male (53%), with a sex ratio of 1.12. The mean age of the patients was 33 years ± 14. The age range of 20 to 40 years was the most represented (42%). Fifteen percent (15%) of patients were living with HIV. The majority of patients were from urban areas (56.4%). Forty-nine percent (49%) of the patients worked in the informal sector. Clinically, the reasons for consultation were dominated by fever, alteration of general condition, neurological disorders, digestive disorders, respiratory signs, urinary signs and diffuse pain. The physical examination showed that 48.1% of the patients had meningeal irritation syndrome, 10% had convulsions and 10% had focal signs, trismus was present in 4% of the patients and facial paralysis in 3%. In the digestive system, hepatomegaly was present in 29% of patients and digestive candidiasis in 31%. Respiratory examination showed crepitus and fluid effusion syndrome in 26.83% and 20.62% of patients respectively. The presumptive diagnosis was dominated by bacterial meningitis, salmonellosis and bronchopneumonia with banal germs. In terms of treatment, the beta-lactam family of drugs was the most prescribed. They were followed by aminoglycosides and fluoroquinolones. The evolution was marked by the death of 50 patients (15%). Conclusion: The most prescribed molecules belong to the family of Beta-lactam. And this prescription improved the outcome of patients. Bacterial susceptibility studies will allow better orientation of probabilistic antibiotic therapy in order to limit the emergence of multi-resistant bacteria.

Successful Treatment of Peritoneal Dialysis Related Peritonitis from Multi-Drug Resistant Sphingomonas paucimobilis with Combination Therapy: A Case Report

Sphingomonas paucimobilis is an emerging gram-negative aerobic bacterium, generally causing infections in immunocompromised patients. Few data are available about peritonitis in peritoneal dialysis due to this pathogen. The clinical courses and outcomes of peritonitis are variable, with a high frequency of catheter removal and peritoneal dialysis withdrawal. No guidelines are available for the treatment of Sphingomonas paucimobilis related peritonitis, due to its emerging role as pathogen, the high antibiotic resistance and unpredictable antibiotic sensitivity. Here, we describe a case of Sphingomonas paucimobilis peritonitis in a 52-year-old diabetic patient in Continuous Cycler-Assisted Peritoneal Dialysis (CCPD) for 4 months, successfully treated with a combined intraperitoneally administration of meropenem (250 mg/L) and ciprofloxacin (100 mg/L) for 21 days. No hospital admission and change of peritoneal dialysis scheme were needed;no relapses of peritonitis were observed during 18 months of follow-up.

Aeromonas hydrophila infection in acute myeloid leukemia: A case report

Rationale:Aeromonas hydrophila,a bacterium commonly found in a variety of soils,aquatic habitats,and other natural environments,is known for causing infections and hemorrhagic diseases in both aquatic and terrestrial animals.Patients with leukemia,when infected by Aeromonas hydrophila following chemotherapy,face an increased risk of developing necrotizing fasciitis.Patient concerns:A 48-year-old male with a history of acute myeloid leukemia presented with swelling and pain in his right hand after being stabbed by a grass carp two days ago.The injury occurred on the fifth day after his last chemotherapy session when he was accidentally punctured in the right thumb and ring finger by a carp while fishing.Two days following the injury,the skin isurrounding the wound turned black immediately,while the rest of his hand was reddened,swollen,and bleeding.Diagnosis:Aeromonas hydrophila infection in the soft tissue of the right hand.Interventions:Intravenous antibiotics and local debridement.Outcomes:The patient experienced an alleviation of systemic poisoning symptoms,effective control of the local wound infection.Lessons:It is important for physicians to appreciate the potential for highly unusual and life-threatening infections in patients with acute myeloid leukemia.Early diagnosis and prompt treatment can prevent the development of necrotizing fasciitis and save patients’lives.

Pantoea SPP: A New Nosocomial Infection in the Neonatal Intensive Care Unit

Pantoea SPP is a gram-negative bacillus, which usually colonizes plants, soil and water. This pathogen very rarely causes neonatal sepsis. The most common infections caused by Pantoea SPP are septic arthritis or synovitis, meningitis frequently complicated by brain abscess, upper respiratory infections, and peritonitis. We present the case of a premature infant who presented neonatal respiratory distress and whose evolution was complicated by the occurrence of a nosocomial infection for which a blood culture was performed isolating the germ Pantoea SPP. The patient’s management was initially centered on non-invasive ventilation with antibiotherapy based on carbapenem and aminoglycoside. Due to the clinical and biological worsening, the neonate was intubated and sedated and put on colymicin. The evolution was unfavorable marked by a death at 16th days of life. Considering the high pathogenicity of this germ and its multi-resistance to antibiotics, it is crucial to know the clinical spectrum of Panteoa SPP infections in neonatal intensive care units, in order to palliate the fulminant evolution of multifocal attacks due to this germ.

Nosocomial Klebsiella variicola Infection in Neonatal Intensive Care: A New Emerging Pathogen

Klebsiella variicola is a human pathogen that has been misidentified as K. pneumoniae. This misidentification has led to a lack of understanding of important clinical and biological aspects of this bacterial species. It is responsible for serious and potentially fatal infections, with a prevalence of multi-resistance to routine antibiotics. We present through three clinical observations, the case of three newborns having been hospitalized in the neonatal intensive care unit and whose evolution was complicated by the occurrence of a nosocomial infection in front of which a blood culture was done on blood agar, with a manual antibiogram on antibiotic disks, isolated the germ Klebsiella variicola. The management of the newborns was initially centered on non-invasive ventilation with a bi-antibiotic therapy based on carbapenem and amikacin for two newborns and switched to colymicin for the third case. Newborn follow-up was based on assessment of general condition, clinical signs of infection, as well as a biological control made of a blood count, a c-reactive protein, a complete ionogram, and a blood culture, every four days or if signs of clinical call. The evolution was favorable for two cases with good clinical and biological improvement, and complicated by death due to alveolar hemorrhage in the third case. Given the high pathogenicity of this germ, and the frequency of misidentification, it is crucial to know the clinical spectrum of Klebsiella variicola infections in neonatal intensive care units, in order to adapt the antibiotic therapy and to mitigate the fulminant evolution of this germ.

Erysipelas in Children: Risk Factors and Management in the Pediatric Emergency Department

The aim of this study is to describe the epidemiological, clinical, biological profile, etiology and management of erysipelas in pediatric emergency departments. In this retrospective study carried out over a period of 12 months, we identified 20 cases of erysipelas, with an incidence of 2%, and a female predominance of 65% of cases. Age average patient age was 6 years, and the average consultation time was 5 days. The Diagnosis of erysipelas is mainly based on clinical features, including the presence of erythema associated with inflammatory signs, which were present in all cases. Satellite lymphadenopathy was observed in five cases, and fever was present in all patients. The therapeutic approach is mainly based on the administration of injectable antibiotics in children, using amoxicillin-clavulanate dose of 80 mg/kg/day in three doses.

Osteomyelitis in diabetic foot:A comprehensive overview

Foot infection is a well recognized risk factor for major amputation in diabetic patients. The osteomyelitis is one of the most common expression of diabetic foot infection, being present approximately in present in 10%-15% of moderate and in 50% of severe infectious process. An early and accurate diagnosis is required to ensure a targeted treatment and reduce the risk of major amputation. The aim of this review is to report a complete overview about the management of diabetic foot osteomyelitis. Epidemiology, clinical aspects, diagnosis and treatment are widely described according to scientific reccomendations and our experience.

Incidence and risk factors for potentially suboptimal serum concentrations of vancomycin during cardiac surgery

AIMTo investigate the incidence and risk factors for van-comycin concentrations less than 10 mg/L during cardiac surgery.METHODSIn this prospective study, patients undergoing cardiac surgery received a single dose of 1000 mg of van-comycin. Multiple arterial samples were drawn during surgery. Exclusion criteria were hepatic dysfunction; renal dysfunction; ongoing infectious diseases; solid or hematologic tumors; severe insulin-dependent diabetes; body mass index of 〈 17 or 〉 40 kg/m2; pregnancy or lactation; antibiotic, corticosteroid, orother immunosuppressive therapy; vancomycin or non-steroidal anti-inflammatory drug therapy in the previous2 wk; chemotherapy or radiation therapy in the previous 6 mo; allergy to vancomycin or cefazolin; drug abuse; cardiac surgery in the previous 6 mo; previous or scheduled organ transplantation; preoperative stay in the intensive care unit for more than 24 h; emergency procedure or lack of adequate preparation for surgery; and participation in another trial.RESULTSOver a 1-year period, 236 patients were enrolled, and a total of 1682 serum vancomycin concentrations （median 7/patient） were measured. No vancomycin levels under 10 mg/L were recorded in 122 out of 236 patients （52%）, and 114 out of 236 patients （48%） were found to have at least 1 serum sample with a vancomycin level 〈 10 mg/L; 54 out of 236 patients （22.9%） had at least 5 serum samples with a vancomycin level lower than 10 mg/L. Vancomycin infusion was administered for 60 min in 97 out of 236 patients （41%）. In 47 patients （20%）, the duration of infusion was longer than 60 min, and in 92 patients （39%） the duration of infusion was shorter than 60 min. The maximum concentration and area under the concentration-time curve were significantly higher in patients with no vancomycin levels less than 10 mg/L （ P 〈 0.001）. The multivariate analysis identifiedfemale gender, body mass index （BMI） 〉 25 kg/m , and creatinine clearance above 70 mL/min as risk factors for vancomycin levels less than 10 mg/L.CONCLUSIONResults of this study identified female gender, BMI 〉 25 kg/m2, and creatinine clearance above 70 mL/min as risk factors for suboptimal vancomycin serum concentration during cardiac surgery; no relationship was found bet-ween infusion duration and vancomycin levels less than 10 mg/L. These findings call attention to the risk of facilitating the emergence of vancomycin-resistant methicillin-resistant Staphylococcus aureus strains.

What is the optimal treatment for appendiceal mass formed after acute perforated appendicitis?

We read with great interest the editorial article by Meshikhes AWN published in issue 25 of World J Gastroenterol 2011.The article described the advantages of emergency laparoscopic appendectomy compared with interval appendectomy as a new safe treatment modality for the appendiceal mass.The author concluded that the emergency laparoscopic appendectomy was a safe treatment modality for the appendiceal mass,and might prove to be more cost-effective than conservative treatment,with no need for interval appendectomy.However,we would like to highlight certain issues regarding the possibility of percutaneous catheter drainage to successfully treat the appendiceal mass,with no need for appendectomy,too.

Mycobacterium abscessus infection after facial injection of argireline:A case report

BACKGROUND The incidence of infection with Mycobacterium abscessus(M.abscessus)has increased in recent years.This increase is partly associated with invasive cosmetic procedures.CASE SUMMARY The purpose of this case summary is to increase clinicians'awareness of M.abscessus infection and reduce mycobacterial infection caused by cosmetic procedures.We report the case of a 45-year-old woman who received acetyl hexapeptide-8(argireline)injections in the forehead and temples,and erythema,nodules,and abscesses appeared at the injection sites after one week.The pus specimens were examined by microbiological culture and confirmed to be positive for M.abscessus.Clarithromycin 500 mg twice daily and moxifloxacin 400 mg once daily were administered for 5 mo and the lesions gradually subsided.CONCLUSION We report here for the first time a case of infection with M.abscessus after argireline injection.This condition is easily misdiagnosed as a common bacterial infection.Microbiological examinations are helpful for diagnosis and standardized cosmetic procedures can prevent infection with M.abscessus.

Successful management of infected right iliac pseudoaneurysm caused by penetration of migrated inferior vena cava filter:A case report

BACKGROUND Indwelling inferior vena cava(IVC)filters might cause various complications,including filter penetration,filter fracture,filter migration,and thrombosis of the IVC.Penetration and migration complications are common,while a caudal migrated double-basket filter with associated infected iliac pseudoaneurysm has seldom been reported.CASE SUMMARY We report a 64-year-old female admitted for sudden onset of severe right abdominal pain after IVC filter placement for 3 mo.The patient had a history of failed endovascular IVC filter retrieval.Computed tomography showed that the retrieval hook of the filter penetrated the right common iliac artery and vein,leading to right iliac artery pseudoaneurysm accompanied by right ureteral obstruction with ipsilateral hydronephrosis,and bilateral iliac veins were occluded.Emergency open repair was performed to remove the IVC filter,the right iliac pseudoaneurysm,and the compromised segments of the iliac veins and IVC with right common iliac artery reconstruction.Staphylococcus aureus was isolated from the tissue culture.The patient was discharged on postoperative day 12 with anticoagulation therapy and antibiotic therapy after discharge.Six-month follow-up computed tomography revealed that the right common iliac artery was patent,and only mild hydronephrosis was detected.CONCLUSION An indwelling IVC filter,even‘embedded’within organized thrombus,could still cause life-threatening complications.Open procedures remain the last resort for IVC filters with severe complications.

Analysis of the clinical efficacy of two-stage revision surgery in the treatment of periprosthetic joint infection in the knee:A retrospective study

BACKGROUND Periprosthetic joint infection(PJI)is a catastrophic complication that can occur following total knee arthroplasty(TKA).Currently,the treatment for PJI mainly includes the use of antibiotics alone,prosthetic debridement lavage,primary revision,secondary revision,joint fusion,amputation,etc.AIM To explore the clinical effect of two-stage revision surgery for the treatment of PJI after TKA.METHODS The clinical data of 27 patients(3 males and 24 females;age range,47–80 years;mean age,66.7±8.0 years;27 knees)with PJI treated with two-stage revision surgery in our hospital between January 1,2010 and December 31,2020 were analyzed retrospectively.The following outcomes were compared for changes between preoperative and last follow-up results:Erythrocyte sedimentation rate(ESR),C-reactive protein(CRP),visual analogue scale(VAS)scores,Hospital for Special Surgery(HSS)scores,knee range of motion(ROM),and infection cure rates.RESULTS All 27 patients were followed up(range,13–112 mo).The ESR(14.5±6.3 mm/h)and CRP(0.6±0.4 mg/dL)of the patients at the last follow-up were significantly lower than those at admission;the difference was statistically significant(P<0.001).The postoperative VAS score(1.1±0.7),HSS score(82.3±7.1),and knee ROM(108.0°±19.7°)were significantly improved compared with those before the surgery;the difference was statistically significant(P<0.001).Of the 27 patients,26 were cured of the infection,whereas 1 case had an infection recurrence;the infection control rate was 96.3%.CONCLUSION Two-stage revision surgery can effectively relieve pain,control infection,and retain good joint function in the treatment of PJI after TKA.

Obligate aerobic, gram-positive, weak acid-fast, nonmotile bacilli, Tsukamurella tyrosinosolvens: Minireview of a rare opportunistic pathogen

Tsukamurella species are obligate aerobic,gram-positive,weak acid-fast,nonmotile bacilli.They are found in various environments,such as soil,water,sludge,and petroleum reservoir wastewater,and belong to the order Actinomycetales.In 2016,there was a reclassification of species within the genus Tsukamurella,merging the species Tsukamurella tyrosinosolvens(T.tyrosinosolvens)and Tsukamurella carboxydivorans.Tsukamurella species are clinically considered to be a rare opportunistic pathogen,because most reported cases have been related to bacteremia and intravascular prosthetic devices and immunosuppression.To date,it has been isolated only from human specimens,and has always been associated with clinical disease;human infections are very rare.Reported infections have included pneumonia,brain abscesses,catheter-related bloodstream infections,ocular infections,bacteremia,and sepsis presenting with septic pulmonary emboli in patients who are immunocompromised.To date,there is no commercially available test for identification.On the other hand,sequence-based identification,including matrix-assisted laser desorption ionization time-of-flight mass spectrometry,is an alternative method for identifying clinical isolates that are either slow growers or difficult to identify through biochemical profiling.The golden standards for diagnosis and optimal management still remain to be determined.However,newer molecular biological techniques can provide accurate identification,and contribute to the appropriate selection of definitive therapy for infections caused by this organism.Combinations of several antimicrobial agents have been proposed for treatment,though the length of treatment for infections has yet to be determined,and should be individualized according to clinical response.Immunocompromised patients often experience severe cases due to infection,and life-threatening T.tyrosinosolvens events associated with dissemination and/or failure of source control have occurred.Favorable prognoses can be achieved through earlier identification of the cause of infection,as well as successful management,including appropriate antibiotic therapy together with source control.Further analyses of similar cases are required to establish the most adequate diagnostic methods and treatment regimens for infections.