Enterobacterales carrying chromosomal AmpC β-lactamases in Europe (EuESCPM): Epidemiology and antimicrobial resistance burden from a cohort of 27 hospitals, 2020-2022

INTRODUCTION

The ESCPM group (Enterobacter species including Klebsiella aerogenes - formerly Enterobacter aerogenes, Serratia species, Citrobacter freundii complex, Providencia species and Morganella morganii) has not yet been incorporated into systematic surveillance programs.

METHODS

We conducted a multicentre retrospective observational study analysing all ESCPM strains isolated from blood cultures in 27 European hospitals over a 3-year period (2020-2022). Diagnostic approach, epidemiology, and antimicrobial susceptibility were investigated.

RESULTS

Our study comprised 6,774 ESCPM isolates. MALDI-TOF coupled to mass spectrometry was the predominant technique for bacterial identification. Susceptibility to new β-lactam/β-lactamase inhibitor combinations and confirmation of AmpC overproduction were routinely tested in 33.3% and 29.6% of the centres, respectively. The most prevalent species were E. cloacae complex (44.8%) and S. marcescens (22.7%). Overall, third-generation cephalosporins (3GC), combined third- and fourth-generation cephalosporins (3GC + 4GC) and carbapenems resistance phenotypes were observed in 15.7%, 4.6%, and 9.5% of the isolates, respectively. AmpC overproduction was the most prevalent resistance mechanism detected (15.8%). Among carbapenemase-producers, carbapenemase type was provided in 44.4% of the isolates, VIM- (22.9%) and OXA-48-enzyme (16%) being the most frequently detected. E. cloacae complex, K. aerogenes and Providencia species exhibited the most notable cumulative antimicrobial resistance profiles, with the former displaying 3GC, combined 3GC + 4GC and carbapenems resistance phenotypes in 15.2%, 7.4%, and 12.8% of the isolates, respectively. K. aerogenes showed the highest rate of both 3GC resistant phenotype (29.8%) and AmpC overproduction (32.1%), while Providencia species those of both carbapenems resistance phenotype (42.7%) and carbapenemase production (29.4%). ESCPM isolates exhibiting both 3GC and combined 3GC + 4GC resistance phenotypes displayed high susceptibility to ceftazidime/avibactam (98.2% and 95.7%, respectively) and colistin (90.3% and 90.7%, respectively). Colistin emerged as the most active drug against ESCPM species (except those intrinsically resistant) displaying both carbapenems resistance phenotype (85.8%) and carbapenemase production (97.8%).

CONCLUSIONS

This study presented a current analysis of ESCPM species epidemiology in Europe, providing insights to inform current antibiotic treatments and guide strategies for antimicrobial stewardship and diagnostics.

Incidence of bacterial and fungal infections in Polish pediatric patients with acute lymphoblastic leukemia during the pandemic

The most common complications related to the treatment of childhood acute lymphoblastic leukemia (ALL) are infections. The aim of the study was to analyze the incidence and mortality rates among pediatric patients with ALL who were treated in 17 Polish pediatric hematology centers in 2020-2021 during the pandemic. Additionally, we compared these results with those of our previous study, which we conducted in the years 2012-2017. The retrospective analysis included 460 patients aged 1-18 years with newly diagnosed ALL. In our study, 361/460 (78.5%) children were reported to have microbiologically documented bacterial infections during chemotherapy. Ten patients (2.8%) died due to sepsis. Fungal infections were reported in 99 children (21.5%), of whom five (5.1%) died due to the infection. We especially observed an increase in bacterial infections during the pandemic period compared to the previous study. The directions of our actions should be to consider antibiotic prophylaxis, shorten the duration of hospitalization, and educate parents and medical staff about complications (mainly infections) during anticancer therapy. It is necessary to continue clinical studies evaluating infection prophylaxis to improve outcomes in childhood ALL patients.

Candida auris Infection in a Meningococcal Septicemia Survivor, Poland

BACKGROUND

Candida auris is an emerging pathogen that constitutes a serious global health threat. It is difficult to identify without specific approaches, and it can be misidentified with standard laboratory methods, what may lead to inappropriate management.

CASE PRESENTATION

We report, probably the first in Poland, C. auris isolation from blood cultures and wound swabs of a young male following meningococcal septicaemia, in February 2019. The patient had been previously hospitalized in the United Arab Emirates. The isolate was rapidly identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry and therefore clinicians were promptly informed on the alert pathogen isolation. The targeted antifungal treatment was successful and infection control measures seemed effective. ITS-based identification and subsequent whole genome sequencing showed that the C. auris isolate belongs to South Asian lineage (clade I).

CONCLUSIONS

C. auris is able to cause outbreaks in healthcare settings. Therefore, it is important to quickly identify C. auris isolates in hospital settings so that healthcare facilities can take proper precautions to limit its spread.

Viral Infection Profile in Children Treated for Acute Lymphoblastic Leukemia—Results of Nationwide Study

Viral infections can be a serious complication of therapy in children with acute lymphoblastic leukemia (ALL). In this study, we focused on the incidence and the profile of viral infection in children with ALL treated in 17 pediatric oncology centers in Poland in the two-year periods of 2018–2019 and 2020–2021. We also compared the frequency of viral infections in 2018–2019 to that in 2020–2021. In 2020–2021, a total of 192 children with ALL had a viral infection during intensive chemotherapy. A total number of 312 episodes of viral infections were diagnosed. The most common infections detected in the samples were: COVID-19 (23%), rhinovirus (18%), and respiratory syncytial virus (14%). COVID-19 and BK virus infections were the reason for the death 1% of all patients. In 2018–2019, a total of 53 ALL patients who had a viral infection were reported and 72 viral events were observed, mainly adenovirus (48.6%), rotavirus (31.9%), and herpes zoster (8.3%). No deaths were reported during this period. The cumulative incidence of viral infections in 2018–2019 was 10.4%, while for 2020–2021, it was 36.7%. In conclusion, a high incidence of COVID-19 infection was observed among pediatric patients with ALL in Poland. The mortality rate in our material was low. The viral profile in ALL children undergoing chemotherapy can be useful for clinicians to improve prophylactic and therapeutic strategies.

Ceftazidime/Avibactam and Other Commonly Used Antibiotics Activity Against Enterobacterales and Pseudomonas aeruginosa Isolated in Poland in 2015–2019

Purpose

Infections caused by resistant Gram-negative bacteria are becoming increasingly common and now pose a serious public health threat worldwide, because they are difficult to treat due to few treatment options and they are associated with high morbidity and mortality. The combination of ceftazidime with the beta-lactamase inhibitor avibactam – seems to be the right choice in this situation. The aim of the study was to evaluate the activity of ceftazidime/avibactam and other commonly used antibiotics against Enterobacterales and Pseudomonas aeruginosa strains isolated within last years in Poland.

Patients and Methods

This study analyzed the antibiotic susceptibility of 1607 Enterobacterales isolates and 543 nonfermenting P. aeruginosa strains collected between 2015 and 2019 in 4 medical laboratories participating in the ATLAS (Antimicrobial Testing Leadership And Surveillance) program in Poland. Unduplicated clinically significant Enterobacterales and P. aeruginosa strains were collected from patients with respiratory, skin and musculoskeletal, genitourinary, abdominal, bloodstream or other infections (ear, eye).

Results

The ceftazidime/avibactam combination demonstrates the highest activity against Enterobacterales (98.9%), in both adults and children, including strains presenting MDR (multidrug-resistant) (97.5%) and ESBL (extended spectrum β-lactamase) (96.3%) phenotypes. The activity of ceftazidime/avibactam increased to 100% when only MBL (metallo-β-lactamase)-negative subset of Enterobacterales was considered. This combination also achieved the second highest activity result (89.3%) after colistin in P. aeruginosa, including isolates of MDR (65.9%) and carbapenem-resistant (CR) phenotypes (54.8%). When MBL-positive isolates were excluded, susceptibility rate of P. aeruginosa increased to 94.7%. It is worth to note that susceptibility of the examined P. aeruginosa strains to ceftazidime/avibactam was very high in children (93.3%), especially in a pediatric intensive care unit (94.2%).

Conclusion

Enterobacterales and P. aeruginosa included in this analysis presented high susceptibility rates to ceftazidime/avibactam. Ceftazidime/avibactam showed the highest activity against Enterobacterales strains among all antibiotics studied, both for the total population as well as for MDR phenotype and ESBL phenotype. Ceftazidime/avibactam also achieved the second highest activity result against P. aeruginosa strains (including MDR and CR phenotypes). These results are much higher when excluding MBL-positive isolates that exhibit intrinsic resistance to ceftazidime/avibactam.

Application of the appropriate molecular biology-based method significantly increases the sensitivity of group B streptococcus detection results

BACKGROUND

Streptococcus agalactiae (group B streptococcus: GBS) is a leading cause of early- and late-onset diseases in neonates. Reliable results of GBS carriage investigation among pregnant women may decrease the incidence of neonatal infection and mortality.

AIM

To compare the results of conventional culture investigation with those of the US Food and Drug Administration-approved nucleic acid amplification test (BD Max GBS (Becton Dickinson)), and to establish our own protocols of standard polymerase chain reaction (PCR).

METHODS

A total of 250 vaginal-rectal swabs from three different hospitals in Bydgoszcz, Poland, were used to evaluate GBS carriage. Standard laboratory technique (overnight culture in broth enrichment media) results were compared with those of BD Max GBS assay (Becton Dickinson) and two standard PCR protocols, established to detect the cfb and 16S rRNA S. agalactiae genes, from the overnight cultures of the samples in the liquid enrichment media.

FINDINGS

The overall GBS carriage was estimated as 16.4-23.2%, depending on the applied detection method. The highest percentage of positive results, from each lab-oratory was obtained with the application of BD Max GBS assay. The differences in the number of positive results obtained with this particular method were statistically significant. Overall, 27 discrepancies were noted for the results obtained with the application of the methods compared.

CONCLUSIONS

The methods applied for GBS detection differ in sensitivity. A culture technique, though very specific, appears to be less sensitive at detecting S. agalactiae compared with the commercially available BD Max GBS assay or in-house PCR protocols established for this purpose.

Varicella-zoster virus infection in the pediatric population with acute lymphoblastic leukemia in Poland

Varicella-zoster virus (VZV) infection in pediatric hemato-oncology patients can be a therapeutic problem when children are exposed to immunosuppression. The aim of this study is to evaluate the incidence of VZV infection, antiviral therapy and outcome in children with ALL treated in polish hemato-oncological centers between 2012 and 2019 years. This study included medical records of 1874 patients, aged 1 to 18 years, with newly diagnosed acute lymphoblastic leukemia. During chemotherapy, 406 children out of 1874 (21.6%) experienced viral infections. The incidence of VZV infection in the whole group children with ALL was 1.8%. Among them, 34 (8.4%) patients were diagnosed with VZV infection. Thirty-five episodes of viral infections were identified. The median time of VCV therapy was 12 days. Herpes zoster infection occurred in 24 (70.6%) children, and varicella in 10 (29.4%) ones. The average time from the start of chemotherapy to the appearance of herpes zoster was 7.26 ± 4.05 months. VZV infection occurred mainly during the maintenance therapy, the reinduction and induction phases. There was no correlation between steroid dosage or type and subsequent zoster. The total lymphocyte count of these patients on the first day of zoster was reduced. No serious complications were observed due to this infection. All patients survived. In conclusion, a low incidence of VZV infection was observed among pediatric patients with ALL in Poland. This analysis indicates that currently used therapeutic methods are effective in children with cancer and VZV infection. The main focus should be on the prevention of delayed chemotherapy.

Adenovirus infection among pediatric patients with cancer and in pediatric recipients of hematopoietic stem cell: A multicenter nationwide study

The aim was to evaluate the incidence, clinical course, and outcome of adenoviral infection (AdVI) in pediatric patients diagnosed and treated due to cancer and in pediatric recipients of hematopoietic stem cell. Over a 72-month period, all-in 5599 children with cancer: 2441 patients with hematological malignancy (HM) and 3158 with solid tumors (ST), and 971 patients after transplantation: 741 after allogeneic (allo-HSCT) and 230 after autologous (auto-HSCT) were enrolled into the study. Among cancer patients, 67 episodes of AdVI appeared in 63 (1.1%) children, including 45 (1.8%) with HM and 18 (0.6%; P < .001) with ST. Within transplanted patients, AdVIs were responsible for 88 episodes in 81 (8.3%) children (P < .001), including 78 (10.5%) patients after allo-HSCT and 3 (1.3%) after auto-HSCT. Time to develop AdVI was short, especially after allo-HSCT. The most common clinical manifestation in cancer patients was enteritis diagnosed in 63 (94.0%) cases, while among HSCT recipient asymptomatic adenoviremia was found in 36 (40.9%) cases and the most common clinical manifestation was urinary tract infection. Cancer patients with disseminated disease, as well as HSCT recipients with either asymptomatic viremia or disseminated disease, received antiviral treatment. The most commonly used first-line therapy was cidofovir. None of the cancer patients died due to AdVI, while within HSCT recipients three patients developed disseminated adenoviral disease and died despite antiviral treatment. In cancer patients, AdVIs are rare and associated with very good prognosis even without specific treatment. However, in allo-HSCT recipients, disseminated disease with fatal outcome is more likely to occur.

Infectious complications after hematopoietic stem cell transplantation for primary immunodeficiency in children: A multicenter nationwide study

PURPOSE

The aim of this nationwide study was to evaluate the characteristics of bacterial infections (BI), invasive fungal disease (IFD), and viral infections (VI) in pediatric patients with PID after allogeneic hematopoietic stem cell transplantation (allo-HSCT).

PATIENTS AND METHODS

In total, 114 HSCT recipients were enrolled into the study. At least one infectious complication (IC) was diagnosed in 60 (52.6%) patients aged 0.1-17.7 years, that is, 59.5% with SCID and 49.4% with non-SCID.

RESULTS

Among 60 HSCT recipients diagnosed with at least one IC, 188 episodes of infectious complications (EIC) were recorded, that is, 46.8% of BI, 41.5% of VI, and 11.7% of proven/probable IFD. According to PID and HSCT donor type, the incidence of EIC was comparable (P = .679). The localization of infections differed significantly due to PID type (P = .002). After each HSCT donor type, the most common site of infection was GI. Overall, BI caused by Gram-positive strains (59.1%) were prevalent, especially Staphylococcaceae. The multidrug-resistant (MDR) pathogens were diagnosed in 52.3%, especially ESBL + Enterobacteriaceae. The profile of VI was comparable for SCID and non-SCID patients (P = .839). The incidence of IFD was comparable for each PID and HSCT donor type. Survival after infection was 91.5% and was comparable for PID and HSCT donor type.

CONCLUSIONS

The rate of patients diagnosed with IC among pediatric PID-HSCT recipients did not depend on PID type, but rather on HSCT donor type. The localization of IC depended on PID and HSCT donor type. Within bacterial infections, predominated Gram-positive strains and the MDR pathogens were responsible for more than half of EIC.

Hematopoietic stem cell transplantation does not increase the risk of infection-related complications for pediatric patients with Hodgkin and non-Hodgkin lymphomas: A multicenter nationwide study

BACKGROUND

Hodgkin (HL) and non-Hodgkin lymphoma (NHL) represent a spectrum of lymphoid malignancies that are often curable with currently applied treatment regimens; however, 15%-30% of lymphoma patients still suffer from relapsed or refractory (rel/ref) disease. Although hematopoietic stem cell transplantation (HSCT) improves outcomes of second-line therapy for lymphoma in childhood, the complication rates in this group of patients, especially infectious complications (IC), remain unclear.

OBJECTIVE

The aim of this population-based cohort study was a retrospective analysis of incidence, epidemiology and profile of bacterial infections (BI), invasive fungal disease (IFD), and viral infections (VI) in primary or rel/ref lymphoma patients, both HL and NHL.

PATIENTS AND METHODS

We subdivided lymphoma patients into three groups: patients with primary conventional chemotherapy/radiotherapy regimens (group A), patients with rel/ref lymphoma treated with second-line chemotherapy (group B), and rel/ref lymphoma patients who underwent HSCT (group C). The medical records of the patients were biannually reported by each pediatric oncology center, and the data were analyzed centrally.

RESULTS

Within 637 patients with primary lymphoma, at least one IC was diagnosed in 255 (40.0%), among 52 patients with rel/ref lymphoma 24 (46.2%) ICs were observed, and in transplanted group, 28 (57.1%) out of 49 children were diagnosed with IC (P = .151). The distribution of etiology of IC differed between the patient groups (A, B, C), with a predominance of BI in group A (85.6% vs 72.0% and 47.9%, respectively), VI in group C (9% and 16.0% vs 46.6%, respectively), and IFD in group B (5.4% vs 12.0% vs 5.5%, respectively). Overall, 500 (68.0%) episodes of bacterial IC were diagnosed in the entire group. Apart from HL patients treated with chemotherapy, in all the other subgroups of patients Gram-positives were predominant. The rate of multidrug-resistant bacteria was high, especially for Gram-negatives (41.1% in group A, 62.5% in group B, and 84.6% in group C). The infection-related mortality was comparable for each group.

CONCLUSIONS

The incidence of IC was comparable during first- and second-line chemotherapy and after HSCT, but their profile was different for primary or re/ref lymphoma and depended on the type of therapy.

Antimicrobial susceptibility of multi-drug and extensively-drug-resistant Escherichia coli to ceftolozane-tazobactam and ceftazidime-avibactam: An in vitro study*

Aim: <i>Escherichia coli</i> is one of the Gram-negative bacteria, known to cause many nosocomial infections. Multi-drug (MDR) and extensively-drug resistant (XDR). <i>E. coli</i> are of particular note, due to significant limitations in antibiotic therapy. Ceftolozane-tazobactam and ceftazidime-avibactam are novel therapeutic options against Gram-negative bacteria; hence the aim of this study was to evaluate and compare the <i> in vitro </i> activity of ceftolozane-tazobactam and ceftazidime-avibactam against MDR and XDR clinical <i>E. coli</i> isolates. Material/Methods: The study included 100 non-replicate <i>E. coli</i> isolates derived from clinical samples of patients hospitalized in teaching hospitals. Bacteria were identified by applying mass spectrometry in the MALDI Biotyper system (Bruker). ESBL (bla_CTX-M-1group, bla_CTX-M-9group) and carbapenemase (bla_KPC, bla_VIM, bla_NDM, bla_OXA-48, bla_OXA-181) genes were detected using the eazyplex® SuperBug CRE test, based on a loop-mediated isothermal amplification (LAMP). The in vitro susceptibility to ceftolozane-tazobactam and ceftazidime-avibactam was tested using validated MIC Test strips (Liofilchem). Results: All 84 extended-spectrum β-lactamase-producing (ESBL) <i>E. coli</i> isolates were susceptible to ceftazidime-avibactam and 83 to ceftolozane-tazobactam. Among 17 <i>E. coli</i> isolates with resistance to at least one of the carbapenems, three (17.6%) were susceptible to ceftolozane-tazobactam and ceftazidime-avibactam. All 14 blaVIM gene-positive <i>E. coli</i> isolates were resistant to both ceftolozane-tazobactam and ceftazidime-avibactam. Both antibiotics were active against bla_CTX-M-9group and bla_OXA-48 gene-positive <i>E. coli</i> isolates, but they were not active against bla_CTX-M-1group and bla_VIM gene-positive isolates. Conclusions: Ceftolozane-tazobactam and ceftazidime-avibactam are alternative, non-carbapenem therapeutic options for ESBL-positive <i>E. coli</i> strains, and they are promising in the treatment of carbapenem-resistant <i>E. coli</i> strains, but not for those carrying the metallo-β-lactamase enzymes. Both drug combinations have comparable activity against ESBL, however, lower MIC values were found for ceftazidime-avibactam.

Epidemiology and outcome of invasive fungal disease in children after hematopoietic cell transplantation or treated for malignancy: Impact of national programme of antifungal prophylaxis

The objective of the study was the analysis of incidence and outcome of invasive fungal disease (IFD) in children treated for malignancy (PHO, paediatric hematology-oncology) or undergoing hematopoietic cell transplantation (HCT) over a period of six consecutive years in nationwide study. A total number of 5628 patients with newly diagnosed malignancies and 971 patients after HCT (741 allo-HCT and 230 auto-HCT) were screened for infectious complications in biennial reports. IFD incidence was lower among PHO patients: 8.8% vs 21.2% (P < .0001) and survival from IFD was better: 94.2% vs 84.1% (P < .0001). Auto-HCT patients had lower incidence (10.9% vs 24.4%) and lower mortality than allo-HCT patients. Introduction of national antifungal prophylaxis programme in HCT and acute leukaemia patients decreased incidence of IFD in HCT (from 23.1% to 13.4%) and AML on conventional chemotherapy (from 36% to 23%) but not in ALL patients during chemotherapy. In multivariate analysis, the incidence of IFD was higher in patients after HCT, diagnosed for ALL, AML or NHL, and in patients > 10 years old. Factors contributing to death with infection were as follows: undergoing HCT, diagnosis of acute leukaemia (ALL or AML) and duration of treatment of infection > 21 days. In conclusion, the incidence of IFD in allo-HCT and in AML patients on chemotherapy has decreased after introduction of national programme of antifungal prophylaxis, while the incidence of IFD in ALL patients on chemotherapy did not change significantly. The outcome of IFD both in PHO and HCT patients has largely improved in comparison with historical international data.

Age-dependent determinants of infectious complications profile in children and adults after hematopoietic cell transplantation: lesson from the nationwide study

Incidence and outcome of microbiologically documented bacterial/viral infections and invasive fungal disease (IFD) in children and adults after hematopoietic cell transplantation (HCT) were compared in 650 children and 3200 adults in multicenter cross-sectional nationwide study. Infections were diagnosed in 60.8% children and 35.0% adults, including respectively 69.1% and 63.5% allo-HCT, and 33.1% and 20.8% auto-HCT patients. The incidence of bacterial infections was higher in children (36.0% vs 27.6%; p < 0.0001). Infections with Gram-negative bacteria were more frequent than Gram-positives in adults (64.6% vs 44.8%; p < 0.0001). Outcome of bacterial infections was better in children (95.5% vs 91.4%; p = 0.0011). The IFD incidence (25.3% vs 6.3%; p < 0.0001) and outcome (88.0% vs 74.9%; p < 0.0001) were higher in children. The incidence of viral infections was higher in children after allo-HCT (56.3% vs 29.3%; p < 0.0001), and auto-HCT (6.6% vs 0.8%; p < 0.0001). Outcome of viral infections was better in children (98.6% vs 92.3%; p = 0.0096). Infection-related mortality was 7.8% in children and 18.4% in adults (p < 0.0001). No child after auto-HCT died of infection. Adult age, mismatched transplants, acute leukemia, chronic GVHD, CMV reactivation, infection with Gram-negatives, and duration of infection > 21 days were risk factors for death from infection. In conclusion, pediatric patients have 2.9-fold higher incidence and 2.5-fold better outcome of infections than adults after HCT.

Infections in children with acute myeloid leukemia: increased mortality in relapsed/refractory patients

The aim of this nationwide study was to describe the epidemiology and profile of bacterial infections (BI), invasive fungal disease (IFD) and viral infections (VI) in patients with de novo and relapsed/refractory (rel/ref) acute myeloid leukemia (AML). Within the studied group of 250 children with primary AML, at least one infectious complication (IC) was diagnosed in 76.0% (n = 190) children including 85.1% (n = 504) episodes of BI, 8.3% (n = 49) - IFD and 6.6% (n = 39) - VI. Among 61 patients with rel/ref AML, at least one IC was found in 67.2% (n = 41) of children including 78.8% (n = 78) of BI, 14.1% (n = 14) of IFD and 7.1% (n = 7) of VI. In all AML patients, within BI Gram-negative strains were predominant. Half of these strains were multi-drug resistant. Characteristics of IFD and VI were comparable for de novo and rel/ref AML. The infection-related mortality was significantly higher, while survival from infection was significantly lower in patients with rel/ref disease.

Infectious profile in children with ALL during chemotherapy: A report of study group for infections

INTRODUCTION

The treatment-related mortality in currently published studies of acute lymphoblastic leukemia (ALL) in children is 2-4%, mainly due to infections. The aim of the study was to analyse the incidence, epidemiology, profile of infection and the death rate in children with ALL.

PATIENTS AND METHODS

The retrospective analysis included 1363 patients, aged 1-18 years, with newly diagnosed ALL, who were treated in 17 pediatric hematology centers between 2012 and 2017 in Poland. The patients received therapy according to the ALL IC-BFM 2002 and 2009 (International Berlin-Frankfurt-Munster Study Group) protocols.

RESULTS

In our study, 726 out of 1363 (53.2%) children were reported to have a microbiologically documented bacterial infection during chemotherapy. 1511 episodes of these infection were diagnosed. A total number of 251/1363 (18.4%) children experienced a viral infection. 304 episodes were documented by PCR test (polymerase chain reaction). A fungal infection was reported in 278 (20.4%) children, including 10.1% of probable, 6.0% of proven, 83% of possible diagnosis. A higher frequency of fungal infection was noted in the recent years. In our material, the rate of death was 2.4%, mainly due to fungal infection.

CONCLUSIONS

Our results present the epidemiology of infectious disease in the Polish ALL patient population. The most frequent were bacterial infections, followed by fungal and viral ones. Similar to the previously published data, the mortality rate in our material was 2.4%.

Incidence, course, and outcome of Clostridium difficile infection in children with hematological malignancies or undergoing hematopoietic stem cell transplantation

Clostridium difficile infection (CDI) is one of the most common causes of nosocomial infectious diarrhea in children during anticancer therapy or undergoing hematopoietic stem cell transplantation (HSCT) in Europe. Immunosuppression in these patients is a risk factor for CDI. Malignant diseases, age, acute graft-versus-host disease (aGVHD), HLA mismatch, or use of total body irradiation may play an important role in CDI course. The aim of this study was to evaluate the incidence, course, and outcome of CDI in children treated for malignancy or undergoing HSCT. Between 2012 and 2015, a total number of 1846 patients were treated for malignancy in Polish pediatric oncological centers (PHO group) and 342 underwent transplantation (HSCT group). In PHO group, episodes of CDI occurred in 210 patients (14%). The incidence of CDI was higher in patients with hematological malignancies in comparison to that with solid tumors. Patients with acute myeloblastic leukemia had shorter time to episode of CDI than those with acute lymphoblastic leukemia. Patients over 5 years and treated for acute leukemia had more severe clinical course of disease in PHO group. In HSCT group, CDI occurred in 29 (8%) patients. The incidence of CDI was higher in patients transplanted for acute leukemia. The recurrence rate was 14.7% in PHO and 20.7% in HSCT patients. CDI incidence was highest in patients with hematological malignancies. Most of patients experienced mild CDI. Age < 5 years and diagnosis other than acute leukemia were the positive prognostic factors influencing clinical CDI course.

Diversity of extended-spectrum beta-lactamase-producing Escherichia coli rods

INTRODUCTION

The aim of the study was to evaluate genetic relatedness and antimicrobial susceptibility of extended-spectrum beta-lactamase-producing E. coli strains isolated from patients hospitalized in the University Hospital in Bydgoszcz (Poland).

MATERIAL AND METHODS

The study included 33 extended-spectrum beta-lactamase-producing E. coli strains isolated from 31 patients. The chromosomal DNA was extracted from the strains and separated by pulsed-field gel electrophoresis. Antimicrobial susceptibility testing was performed by the agar dilution method and carried out according to the European Committee on Antimicrobial Susceptibility Testing recommendations.

RESULTS

According to the pulsed-field gel electrophoresis results, 32 distinct pulsotypes were revealed. Based on Molecular Analyst Fingerprinting software analysis, the studied isolates were divided into four subgroups: 6 (18.2%) isolates showing similarity greater than 90% (group A); 19 (57.6%) showing 80-90% similarity (group B); 7 (21.2%) showing 70-79% similarity (group C); and one isolate with less than 70% similarity (group D). Among E. coli isolates showing similarity greater than 90%, four antimicrobial patterns were noted. Among the isolates showing 80-90% similarity, 18 antimicrobial patterns were observed. E. coli isolates showing 70-79% similarity presented 6 antimicrobial patterns.

CONCLUSIONS

Our results show a high degree of genetic diversity of extended-spectrum beta-lactamase-producing E. coli isolates. However, based on a similarity of ≥80%, almost 75% of E. coli isolates were clonally related. Although it is difficult to identify definitive transmission events based on the recovery of indistinguishable pulsed-field gel electrophoresis types alone, we speculate that extended-spectrum beta-lactamase-producing E. coli strains may have disseminated throughout the hospital.

Comparison of detection methods for extended-spectrum beta-lactamases in Escherichia coli strains

INTRODUCTION

Detection of extended-spectrum beta-lactamases (ESBLs) could be a major challenge for microbiologists--the difficulties arise mainly from the phenotypic differences among strains.

MATERIALS AND METHODS

Evaluation of ESBLs was performed on 42 strains of E. coli by: 1) DDST on MHA, 2) DDST on MHA with cloxacillin, 3) CT on MHA, according to CLSI, 4) CT on MHA with cloxacillin, 5) Etest ESBL (AB Biodisk), 6) CHROMagarTM ESBL (GRASO), 7) ChromID® ESBL (bioMérieux), and 8) automatic system VITEK2 ESBL test (bioMérieux).

RESULT

Positive results were obtained for 20 strains using method 1, for 18 strains using method 2, 17 by method 3, 14 by method 4, 11 by method 5, 39 by method 6, 40 by method 7, and 15 by method 8. Using Etest ESBL 6.0 non-determinable results were obtained. The most consistent results were obtained when comparing the results of method 3 with results of method 2 (97.6%), and comparing the results obtained using methods 3 and 8 (95.2%).

CONCLUSIONS

Based on our study we conclude that the chromogenic media can only be used as a screening method for the detection of ESBLs in E. coli rods. Etest is less useful compared to other phenotype methods, due to the impossibility of obtaining results for all the tested strains. Adding cloxacillin to MHA does not increase the frequency of detection of ESBLs in E. coli strains. DDST seems to be the most reliable among phenotypic methods for the detection of ESBLs in E. coli rods.

Human meningitis caused by Streptococcus suis

Streptococcus suis is an important swine pathogen worldwide, which can be transmitted to human beings by direct contact; therefore, S. suis infections occur mainly in people who handle pigs or pork. We present a case of a patient with S. suis meningitis who worked as a butcher in a meat processing plant for 5 years. The 35-year-old man was admitted to the Department of Infectious Diseases in T. Browicz Memorial Central Infectious Disease and Observation Hospital in Bydgoszcz, Poland, with suspected bacterial meningitis. According to his medical history, the patient had been injured during the processing of pork. A microbiological examination of the cerebrospinal fluid and blood revealed S. suis as a single aetiological factor of this infection. The patient was empirically administered cefotaxime (2.0 g at 8-h intervals) and penicillin (9 million U at 8-h intervals). The patient made a complete recovery and his inflammatory markers normalized. Only the hearing deficit of his right ear did not disappear. An otolaryngologist recommended a 4-week steroid therapy. The patient was not examined because he did not report to the clinic. To our knowledge this is the first described case of human meningitis caused by S. suis in Poland.

[Morganella sp. rods--characteristics, infections, mechanisms of resistance to antibiotics]

The Morganella genus is one member of the tribe Proteae, which also includes the genera Proteus and Providencia. These bacteria are commonly present in the environment. Morganella sp. rods are known to be a causative agent of opportunistic hospital infections, mainly urinary tract, wound and blood infections of severe and high mortality, even in cases of an appropriate antibiotic. These bacteria may produce many virulence factors, for example urease, hemolysins, LPS, adhesins and enzymes hydrolyzing and modifying antibiotics commonly used to treat infections. Understanding the diverse biological properties of these rods may be of importance in the development of effective methods of prevention and control of infections with their participation.