Long-term intensive care unit outbreak of carbapenemase-producing organisms associated with contaminated sink drains.

BACKGROUND: Between 2018 and 2022, a Belgian tertiary care hospital faced a growing issue with acquiring carbapenemase-producing organisms (CPO), mainly VIM-producing P. aeruginosa (PA-VIM) and NDM-producing Enterobacterales (CPE-NDM) among hospitalized patients in the adult intensive care unit (ICU). AIM: To investigate this ICU long-term CPO outbreak involving multiple species and a persistent environmental reservoir. METHODS: Active case finding, environmental sampling, whole-genome sequencing (WGS) analysis of patient and environmental strains, and implemented control strategies were described in this study. FINDINGS: From 2018 to 2022, 37 patients became colonized or infected with PA-VIM and/or CPE-NDM during their ICU stay. WGS confirmed the epidemiological link between clinical and environmental strains collected from the sink drains with clonal strain dissemination and horizontal gene transfer mediated by plasmid conjugation and/or transposon jumps. Environmental disinfection by quaternary ammonium-based disinfectant and replacement of contaminated equipment failed to eradicate environmental sources. Interestingly, efflux pump genes conferring resistance to quaternary ammonium compounds were widespread in the isolates. As removing sinks was not feasible, a combination of a foaming product degrading the biofilm and foaming disinfectant based on peracetic acid and hydrogen peroxide has been evaluated and has so far prevented recolonization of the proximal sink drain by CPO. CONCLUSION: The persistence in the hospital environment of antibiotic- and disinfectant-resistant bacteria with the ability to transfer mobile genetic elements poses a serious threat to ICU patients with a risk of shifting towards an endemicity scenario. Innovative strategies are needed to address persistent environmental reservoirs and prevent CPO transmission.

Are C-reactive protein (CRP) and neutrophil to lymphocyte ratio (NLR) predictive markers of successful two-stage prosthetic joint infection management?

The treatment of prosthetic joint infections (PJI) regularly involves a two-stage surgical strategy. The second stage is generally performed when the surgeon estimates that the infection is under control based on either the treatment length or clinical and biological data. We have raised the question whether standardization of C-reactive protein (CRP) and neutrophil to lymphocyte ratio (NLR) values could be either indicative of infection control or predictive of infection recurrence. This was an analytical retrospective and monocentric cross-sectional observational study. The CRP and NLR values were recorded prior to the second-stage surgery in a sample of 100 patients who underwent a two-stage revision arthroplasty following a PJI, and these values were correlated with the absence of infectious recurrence within a 2-year follow-up. The statistical analysis consisted of evaluating the diagnostic validity of each marker, first individually, and then in combination. CRP was shown associated with a 68% sensitivity, 40% specificity, 27% positive predictive value (PPV), and 79% negative predictive value (NPV). The ROC curve was 51.1%. The NLR displayed a 12% sensitivity, 89% specificity, 27% PPV, and 75% NPV. The ROC curve was 47.9%. The combination of the two markers did not fundamentally improve the statistical results, with only a 43% concordance of the two markers, 27% sensitivity, 84% specificity, 37% PPV, and 77% NPV. Measuring CRP and NLR values, either individually or in combination, before the second-stage revision arthroplasty did not turn out to be predictive of either infection recurrence or cure within two years of follow-up. Therefore, an absolute test is still lacking, which would enable us to predict without failure the absence of control or the control of a PJI before or after second-stage revision. Level of evidence: Level III, retrospective cross-sectional study.

Fungal pneumonia in kidney transplant recipients.

Fungal pneumonia is a dreaded complication encountered after kidney transplantation, complicated by increased mortality and often associated with graft failure. Diagnosis can be challenging because the clinical presentation is non-specific and diagnostic tools have limited sensitivity and specificity in kidney transplant recipients and must be interpreted in the context of the clinical setting. Management is difficult due to the increased risk of dissemination and severity, multiple comorbidities, drug interactions and reduced immunosuppression which should be applied as an important adjunct to therapy. This review will focus on the main causes of fungal pneumonia in kidney transplant recipients including Pneumocystis, Aspergillus, Cryptococcus, mucormycetes and Histoplasma. Epidemiology, clinical presentation, laboratory and radiographic features, specific characteristics will be discussed with an update on diagnostic procedures and treatment.

Do fully automated immunoassays for the evaluation of the immune response to SARS-CoV-2 are commutable?

On December 30, 2019, the city of Wuhan, China, experienced an outbreak of unexplained pneumonia. From January 7, 2020, a new betacoronavirus, severe acute respiratory syndrome coronavirus was identified (SARS-CoV-2). The World Health Organization (WHO) has since declared a pandemic with millions of confirmed cases worldwide. As part of the fight against the epidemic, laboratories have a critical role in assessing the reliability of new serological assays before taking part of diagnostic protocols or made available broader to the community and to evaluate commutability between assays. The aim of this study was to perform a comparison between two automated assays for SARS-CoV-2 IgG testing, the MAGLUMI ® 800 and the LIAISON ® XL. Among the patients confirmed positive for COVID-19, the two automated assays were significantly correlated (r = 0.811; p < 0.0001). The overall concordance made for MAGLUMI 2019-nCoV IgG positive/negative vs. LIAISON® SARS-CoV-2 IgG positive/negative results was 79% (Index Kappa of Cohen). We list the discrepancies between the two analyzers among the 44 tested patients. In conclusion, the overall agreement between the two automated assays for SARS-CoV-2 was good. However, the MAGLUMI assay might be more sensitive at the early stages of antibody development and there is a lack of specificity with LIAISON XL.

Clinical characteristics and humoral immune response in healthcare workers with COVID-19 in a teaching hospital in Belgium.

BACKGROUND: Healthcare workers (HCWs) are at high risk of acquiring COVID-19 and could play a role in nosocomial transmission. Since 4th February 2020, Belgian Health authorities reported more than 90,568 cases, of which 8.3% were HCWs. Data on clinical characteristics, sources of infection and humoral immune response of HCWs with COVID-19 remain scarce. AIM: To analyse the clinical characteristics, humoral immune response, sources of contamination, and outcomes among HCWs with COVID-19. METHODS: This retrospective study included 176 HCWs with laboratory-confirmed COVID-19 in a teaching hospital in Belgium. Between 1st March and 31st May 2020, all HCWs with symptoms suspected of COVID-19 were tested by reverse transcription polymerase chain reaction on a nasopharyngeal swab. Serological testing was performed between 55 and 137 days after the onset of symptoms. FINDINGS: Median age was 40.8 years and 75% were female. Median delay between onset of symptoms and diagnosis was 4.39 days. Most frequent symptoms were cough and headache (both 75%). Fever accounted for 68.7%. Most represented professions were nurses (42%). HCWs were mainly infected by patient contact (32.9%); 7.6% required hospitalization and 1.7% were admitted to the intensive care unit. Unfortunately, one HCW died (0.5%). Total antibodies were positive in 109/126 (86.5%). CONCLUSIONS: Clinical presentation of COVID-19 in HCWs does not differ from the general population. However, outcomes were more favourable with a mortality rate lower than that reported in Belgian COVID-19 patients in general (16%). The main source of infection was the hospital setting. Our positive antibodies rate was high but lower than previously reported.

Concordance between superficial swab and deep sampling in post-sternotomy mediastinitis: Single center experience.

OBJECTIVES: Deep sampling (DS) is the gold standard for microbiological diagnosis of post-sternotomy mediastinitis (PSM), however superficial swab (SS) are frequently performed in some centers and antibiotherapy initiated base on their results. We analysed the concordance between superficial swab and deep sampling in PSM. MATERIALS AND METHODS: We analysed retrospectively patients with a PSM between 2010 and 2014 at Saint-Luc University hospital (Belgium). We considered that there was a concordance between SS and DS when the same microorganism was found in the two sampling method in each patient. Patients were stratified in six groups according to microbiology results as Staphylococcus Aureus (SA) sensitive or resistant, coagulase negative Staphylococcus (CoNS), Gram negative bacilli (GNB), other Gram positive bacteria (GPB) and fungi. RESULTS: Thirty-six patients were included. Twenty-five men (69%) and a mean age of 66 years old. The overall concordance between SS and DS was 57%. SA and GNB showed high concordance (100% and 85.7% respectively). For the other groups the concordance was low. The sensitivity and specificity of SS was 97% and 33% respectively. The PPV and NPV of superficial swab was 96% and 50% respectively. CONCLUSION: Microbiological results from SS, even with flocked swabs, except for SA and GNB have low concordance with those obtained from deep sampling. Our data confirm that in PSM, deep sampling is the gold standard for microbiological assessment.

Bacterial pneumonia in kidney transplant recipients.

Bacterial pathogens are the most frequent cause of pneumonia after transplantation. Early after transplantation, recipients are at higher risk for nosocomial infections. The most commonly encountered pathogens during this period are gram-negative bacilli (Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa …), but gram-positive coccus such as Staphylococcus aureus or Streptococcus pneumoniae and anaerobic bacteria can also be found. Empirical antibiotic therapy should be guided by previous colonisation of the recipient and bacterial resistance pattern in the hospital. Six months after transplantation, pneumonias are mostly due to community-acquired bacteria (S. pneumonia, H. influenza, Mycoplasma, Chlamydia and others). Opportunistic pathogens take advantage of the state of immunosuppression which is usually highest from one to six months after transplantation. During this period, but also occurring many years later in the setting of a chronically depressed immune system, bacterial pathogens with low intrinsic virulence can cause pneumonia. The diagnosis of pneumonia caused by opportunistic pathogens can be challenging. The delay in diagnosis preventing the early instauration of adequate treatment in kidney transplant recipients with a depressed immune system, frequently coupled with co-morbid conditions and a state of frailty, will affect prognosis and outcome, increasing morbidity and mortality. This review will focus on the most common opportunistic bacterial pathogens causing pneumonia in kidney transplant recipients: Legionella, Nocardia, Mycobacterium tuberculosis/nontuberculous, and Rhodococcus. Recognition of their specificities in the setting of immunosuppression will allow early diagnosis, crucial for initiation of effective therapy and successful outcome. Interactions with immunosuppressive therapy should be considered as well as reducing immunosuppression if necessary.

Fatal thoracic empyema involving Campylobacter rectus: A case report.

We report the case of a 69-year-old man admitted for septic shock secondary to necrotic pneumoniae complicated by thoracic empyema of fatal issue. Microbiological examination of pleural liquid revealed a mixed anaerobic flora involving Campylobacter rectus and Actinomyces meyeri. Campylobacter rectus is an infrequent anaerobic pathogen of oral origin To our knowledge, this is the first case report of fatal C. rectus - associated thoracic empyema, and only the second reported case in which identification was successfully performed by MALDI-TOF MS.

Acute Bacterial Meningitis and Systemic Abscesses due to Streptococcus dysgalactiae subsp. equisimilis Infection.

Disseminated abscesses due to group G ß-hemolytic Streptococcus dysgalactiae were observed in a 57-year-old cirrhotic patient with the skin being the putative way of entry for the pathogen. S. dysgalactiae is a rare agent in human infections responsible for acute pyogenic meningitis. The mortality rate associated with S. dysgalactiae bacteraemia and meningitis may be as high as 50%, particularly in the presence of endocarditis or brain abscesses. In our patient, main sites of infections were meningitis and ventriculitis, spondylodiscitis, septic arthritis, and soft-tissue infections. In contrast, no endocarditis was evidenced. Cirrhosis-related immune suppression was considered as a pathophysiological cofactor for the condition. Fortunately, clinical status improved after long-term (3 months) antimicrobial therapy.

First Robinsoniella peoriensis aortic cross homograft mycotic pseudoaneurysm: A case report and review of the literature.

Mycotic aortic aneurysm is a rare and challenging complication of aortic homografts caused by an infection and is associated with high morbidity and mortality. We report the first case of an aortic cross homograft mycotic pseudoaneurysm caused by Robinsoniella peoriensis in a 70-year-old man. Our patient underwent surgery for a recurrence of aortic cross mycotic pseudoaneurysm at the level of the aortic homograft he had had 7 years before. A clot-removal of the pseudoaneurysm was surgically carried out and the homograft was completely removed. Anaerobic culture from tissue samples yielded pure growth of a spore-forming Gram-positive rod, identified later as Robinsoniella peoriensis by 16S rRNA gene sequencing. The patient was then discharged with oral clindamycin according to the in vitro susceptibility testing. Identification of R. peoriensis might be challenging in clinical laboratories with no access to molecular methods.

Epidemiology and reporting of candidaemia in Belgium: a multi-centre study.

The primary aim of this study was to collect national epidemiological data on candidaemia and to determine the reporting time of species identification and antifungal susceptibility in clinical practice. During a 1-year period (March 2013 until February 2014), every first Candida isolate from each episode of candidaemia was included prospectively from 30 Belgian hospitals. Identification and susceptibility testing were performed according to local procedures and isolates were sent to the National Reference Center for Mycosis. Species identification was checked by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) and internal transcribed spacer (ITS) sequencing in case no reliable identification was obtained by MALDI-TOF MS. Antifungal susceptibility testing was performed according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) methodology. A total of 355 isolates were retrieved from 338 patients. The mean incidence rate of candidaemia was 0.44 (range: 0.07 to 1.43) per 1000 admissions or 0.65 (range: 0.11 to 2.00) per 10,000 patient days. Candida albicans was most frequently found (50.4 %), followed by C. glabrata (27.3 %) and C. parapsilosis sensu lato (9.8 %). The overall resistance to fluconazole was 7.6 %, ranging from 3.9 % in C. albicans to 20.0 % in C. tropicalis. Only one C. glabrata isolate was resistant to the echinocandins. Four days after blood culture positivity, 99.7 % of the identifications and 90.3 % of the antifungal profiles were reported to the treating clinician. Candidaemia incidence rates differed up to 20-fold among Belgian hospitals; no clear factors explaining this difference were identified. The overall antifungal resistance rates were low but high azole resistance rates were recorded in C. tropicalis.

Neuroinvasive Infection from O117:K52:H-Escherichia coli following Acute Pyelonephritis.

Spontaneous or nosocomial Escherichia coli meningitis remains rare in healthy adults but is still carrying a high mortality rate despite adapted antimicrobial treatment for susceptible strains. A 39-year-old woman was admitted to the hospital with severe subarachnoid haemorrhage complicated by acute hydrocephalus. On hospital day 10, she developed Streptococcus anginosus septicaemia and urinary tract infection due to a multisensitive strain of E. coli. This infection was successfully controlled by antimicrobial therapy. As a late complication in the neurosurgical ward (day 39), she developed fever, alteration of consciousness, and shock, leading to the diagnosis of bacterial meningitis. The culture of blood, cerebrospinal fluid, and urine grew positive for a multisensitive E. coli. The strain was identified as O117:K52:H, a serotype that was until now never associated with acute meningitis or brain abscesses. The source appeared to be the urinary tract with the demonstration of acute pyelonephritis. The patient died on day 94 from delayed complications of multiple brain abscesses.

Difficult to treat osteoarticulars infections : Focus on Mycobacterial and Fungal infection.

Bone and joint infections are rare but often devastating. While bacteria are most commonly encountered organisms, mycobacteria and fungi are less frequent. Management of the latter is often more complex, especially in the presence of foreign material. We will increasingly be faced with mycobacterial and fungal bone infections, as medical conditions and newer therapeutics lead to more immunosuppression. In this article, we will review osteomyelitis, septic arthritis and peri-prosthetic joint infections related to mycobacteria and fungi.

First case of a dog bite wound infection caused by Streptococcus minor in human.

We report the first case of human infection caused by Streptococcus minor in a 51-year-old immunocompetent woman admitted for dog bite injuries. At present, the role of Streptococcus minor in bite wound infections is unknown. Further studies on virulence factors are needed to elucidate its pathogenicity mechanisms.

Breast prosthesis infection and pets: A case report and review of the literature.

INTRODUCTION: Pets are not always the human's best friends, particularly in the presence of comorbidities such as wounds. The following case report describes a Pasteurella multocida infection of a reconstructive breast implant due to a close contact between a cat and its owner. PRESENTATION OF CASE: A 33-year-old woman developed a breast implant infection 13 days after an immediate breast reconstruction following a mastectomy for a multifocal ductal carcinoma. The wound was explored surgically and the implant removed. Culture extracted from fluid around the prosthesis evidenced the presence of P. multocida, a Gram-negative coccobacillus which is present in the oral commensal flora of cats and dogs. CONCLUSION: In the case of breast infection, surgical revision - with or without removal of the implant - is required in order to carry out a meticulous intraoperative cleaning. Antibiotherapy is always necessary in such cases. Particularly when patients presenting comorbidities are concerned, the focus must be put on avoiding close contact of the wound with pets.

Clinical features and outcome of typhoid fever and invasive non-typhoidal salmonellosis in a tertiary hospital in Belgium: analysis and review of the literature.

OBJECTIVES: Typhoid fever (TF) occurs rarely in industrialized countries because of advances in health care and improvement of drinking water. Conversely, non-typhoid salmonellosis (NTS) remains widespread, because of food contamination or asymptomatic carriage. Non-typhoid salmonellosis can be severe when becoming invasive non-typhoid salmonellosis (iNTS). Although established prognostic indicators of the two pathologies are different, direct comparisons between iNTS and TF in the literature remain scarce. The purpose of this study was to analyse and compare demographic, clinical features and outcome of hospitalized patients with TF and iNTS. METHODS: Demographic, clinical features and outcome were retrospectively analysed in a series of patients hospitalized between 2007 and 2012. RESULTS: A total of 33 patients were enrolled, including 13 with established TF and 20 with iNTS. No differences between TF and iNTS patients were observed in incidence of fever, abdominal cramps, diarrhoea, headache, nausea and vomiting and duration of antibiotic therapy (≤ 7 days in both groups). Although the clinical outcome of TF patients was identical to that of iNTS patients, including incidence of complications, length of hospitalization and mortality (1/13 (7.7%) vs 2/20 (10%), P = 0.43), comorbidities were less frequent in the TF group than in the iNTS group (2/13 vs 15/20, P = 0.003). CONCLUSION: The clinical profile and outcome of TF patients are similar to those with iNTS. Although comorbidities are more often associated with iNTS, the results of our study suggest that clinical management of these two diseases should remain similar.

Nocardia prosthetic knee infection successfully treated by one-stage exchange: case report and review.

A 64-year-old man with a history of sarcoidosis on corticosteroids and azathioprine was admitted to our hospital with complaints of worsening left knee pain and swelling for the past 3 weeks. His past medical history is also significant for severe osteoarthritis requiring a cemented total left knee arthroplasty 1 year ago. Diagnostic investigation during his hospital admission eventually led to the diagnosis of Nocardia nova knee prosthetic joint infection in the setting of a disseminated nocardiosis. He was successful treated by one-stage complete hardware exchange in conjunction with an adapted antibiotic therapy regimen (meropenem and doxycycline followed by ceftriaxone and doxycycline). Two years later, his recovery was deemed excellent.

Emergence and dissemination of multi-resistant Gram negative Enterobacteriaceae: lessons to be learnt from local and national surveillance programs in Belgium.

Infections caused by multi drug resistant bacteria (MDRB) constitutes an international health care problem. Since the year 2000, a longitudinal surveillance programme (LSP) and two multicentric surveys (100 hospitals, 826 isolates) were performed to monitor the emergence of MDRB in Belgium. The implementation of a LSP detected the emergence and spread of new types of ESBLs (CTX-M), mostly among community associated E. coli in the setting of a university hospital several years before the large spread and recognition in Belgium of a pathogenic E. coli CTX-M-15 (B2-O25:H4-ST131) pandemic clone (found in extra-intestinal virulent strains). This finding supports the progressive increase in Belgium of systemic infections including UTI caused by MDRB with limited therapeutical options. The real burden of the problem remains however, difficult to estimate in the absence of any surveillance network in Belgium to monitor the epidemiology of antimicrobial resistance in the community. The current Belgian national recommendations for the detection, surveillance, prevention and control of epidemics by ESBL-producing organisms and possibly other MDRBs (eg: Carbapenemase producing Enterobacteriaceae [CPE]) must be updated taking into accounts these new elements. A global coordinated network for antimicrobial surveillance resistance gathering experts (e.g: public health epidemiologists, representative of the national reference centres of antimicrobial resistance, field experts in infection control, infectious disease specialists, other clinicians and general practitioners) must be urgently implemented, including the longitudinal analysis of resistance in different ecosystems (human, animal, water and food).