Efficacy of single antibiotic therapy versus antibiotic combination in implant-free staphylococcal post-surgical spinal infections: a retrospective observational study

BACKGROUND

Post-surgical spinal infections (pSSIs) are a serious complication of spinal surgeries, with Staphylococcus spp. being one of the most prominent bacteria identified. Optimal antimicrobial therapy for staphylococcal spinal infections without spinal implants is not well documented.

METHODS

This single center retrospective 7-year observational study described and compared the outcome (treatment failure or mortality rate one year after diagnosis) of 20 patients with staphylococcal-implant-free pSSI treated with single or combination antibiotics.

RESULTS

Median duration of treatment was 40 days (IQR 38-42), with 6 days (IQR 5-7) on intravenous antibiotics and 34 days (IQR 30-36) on oral therapy. Four patients (20%) underwent new surgical debridement, all due to surgical failure, and 1 patient died within the first year without significant differences between both treatment group.

CONCLUSION

This study raises the possibility of single antibiotic therapy for patients with implant-free post-surgical spinal infections due to Staphylococcus spp.

Prevalence and risk factors of toxigenic Clostridioides difficile asymptomatic carriage in 11 French hospitals

Clostridioides difficile infection (CDI) incidence has increased over the last 20 years. Studies suggest that asymptomatic carriers may be an important reservoir of C. difficile in healthcare settings. We conducted a point prevalence study to estimate the toxigenic C. difficile asymptomatic carriage rate and the associated risk factors in patients >3 years old. Between September 16, 2019 and January 15, 2020, all patients hospitalized in 11 healthcare facilities in the Paris urban area were included in the study. They were screened on the day of the survey for toxigenic C. difficile carriage by rectal swab and interviewed. Isolates were characterized by PCR ribotyping and multiplex PCR targeting toxin genes. A logistic regression model was used to determine the risk factors associated with toxigenic C. difficile asymptomatic carriage using uni- and multivariate analysis in the subpopulation of patients >3 years old. During the study period, 2,389 patients were included and screened. The median age was 62 years (interquartile range 35-78 years) and 1,153 were male (48.3%). Nineteen patients had a previous CDI (0.9%). Overall, 185/2389 patients were positive for C. difficile (7.7%), including 93 toxigenic strains (3.9%): 77 (82.8%) were asymptomatic (prevalence 3.2%) whereas 12 (12.9%) were diarrheic. Prevalences of toxigenic C. difficile were 3.5% in patients >3 years old and 7.0% in ≤3 years old subjects, respectively. Toxigenic strains mainly belonged to PCR ribotypes 106 (n = 14, 15.0%), 014 (n = 12, 12.9%), and 020 (n = 10, 10.8%). Among toxigenic strains, 6 (6.4%) produced the binary toxin. In multivariate analysis, two factors were positively associated with toxigenic C. difficile asymptomatic carriage in patients >3 years old: multidrug-resistant organisms co-carriage [adjusted Odd Ratio (aOR) 2.3, CI 95% 1.2-4.7, p = 0.02] and previous CDI (aOR 5.8, CI 95% 1.2-28.6, p = 0.03). Conversely, consumption of raw milk products were associated with reduced risk of toxigenic C. difficile colonization (aOR 0.5, CI 95% 0.2-0.9, p = 0.01). We showed that there was a low prevalence of asymptomatic toxigenic C. difficile carriage in hospitalized patients. Consumption of raw milk prevents toxigenic C. difficile colonization, probably due to the barrier effect of milk-associated bacteria.

TIVAP-related infection due to Gram-negative aerobic bacilli: should TIVAP stay or should it go?

We aimed to describe the outcome of totally implantable venous-access port (TIVAP)-related infections due to Gram-negative aerobic bacilli (Pseudomonas aeruginosa and other Pseudomonas spp., Acinetobacter spp., and Stenotrophomonas maltophilia), or GNAB, and assess the safety of conservative treatment. We conducted a retrospective study in a French teaching hospital, from January 2016 to December 2020, including adult patients treated for TIVAP-related infection due to GNAB. Success of conservative treatment was defined as a functional TIVAP 3 months after infection with no recurrence. We performed a bivariate analysis and analyzed causes for treatment failure. We included 68 patients (53 TIVAP-related bloodstream infections, 11 TIVAP-related infections, and 4 probable TIVAP-related infections) due to GNAB, mostly P. aeruginosa (50/68, 74%). TIVAP removal was initially decided for 49/68 patients (72%). Among the 19/68 (28%) patients with conservative treatment (all for infections caused by P. aeruginosa), 5/19 (26%) had successful treatment, 7/19 (37%) experienced failure (without sepsis or septic shock), 6/19 (32%) died within 3 months without TIVAP removal and no signs of infection recurrence, and 1 patient had TIVAP removal as it was no longer required. TIVAP-related infections caused by GNAB frequently require TIVAP removal. Conservative treatment can be performed in selected patients with a non-complicated infection caused by P. aeruginosa, who can benefit from the continuation of antineoplastic chemotherapy or palliative care. Treatment failures were not associated with sepsis or septic shock.

Faecal carriage of multidrug-resistant bacteria and associated risk factors: results from a point prevalence study

OBJECTIVES

Since 2003, incidences of carbapenemase-producing Gram-negative bacilli (CP-GNB) and vancomycin-resistant Enterococcus faecium (VRE) have steadily increased in France. We therefore conducted a point prevalence study to estimate carriage rates of CP-GNB, VRE and ESBL-producing Enterobacterales (ESBL-PE) and associated risk factors.

METHODS

Between September 2019 and January 2020, all inpatients hospitalized on a given day in 11 teaching hospitals in the Paris urban area were eligible. Patient interviews and rectal swab screening results were recorded by dedicated nurses. The swabs were plated onto selective chromogenic media and processed using the GeneXpert® system.

RESULTS

Of 2396 patients, 364 (15.2%) yielded at least one multiresistant bacterial isolate, including 29 CP-GNB carriers (1.2%), 13 VRE carriers (0.5%) and 338 ESBL-PE carriers (14%). In 15 patients (4.4% of ESBL-PE carriers and 36.6% of CP-GNB/VRE carriers), concomitant CP-GNB/VRE and ESBL-PE carriage was observed. In 7/29 CP-GNB and 7/13 VRE carriers, carbapenemase production and vanA in the screening samples was only detected with Xpert® tests. The OXA-48 gene was predominant in 13/34 CP-GNB isolates from 29 carriers. From the 338 ESBL-PE carriers, 372 isolates were recovered, mainly Escherichia coli (61.2%). Among 379 children, 1.1% carried a CP-GNB/VRE strain, and 12.4% carried an ESBL strain. Previous hospitalization outside mainland France, previous antimicrobial treatment and previous ESBL-PE carriage were the main risk factors associated with CP-GNB and/or VRE carriage.

CONCLUSIONS

The low CP-GNB and VRE prevalence likely reflects the French policy to limit intrahospital spread of CP-GNB and VRE strains.

No SARS-CoV-2 reinfection among staff health-care workers: Prospective hospital-wide screening during the first and second waves in Paris

Objectives

Risk of reinfection with SARS-CoV-2 among health-care workers (HCWs) is unknown. We assessed the incidence rate of SARS-CoV-2 reinfection in the real-life setting of a longitudinal observational cohort of HCWs from the Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, France, during the first and second waves of COVID-19 epidemic.

Methods

From March to December 2020, HCWs were subjected to molecular and serology testing of SARS-CoV-2. Reinfection was defined as a positive test result during the first wave, either by serology or PCR, followed by a positive PCR during the second wave. Evolution of COVID-19 status of HWCs was assessed by a Sankey diagram.

Results

A total of 7765 tests (4579 PCR and 3186 serology) were carried out and 4168 HCWs had at least one test result during the follow-up period with a positivity rate of 15.9%. No case of reinfection during the second wave could be observed among 102 positive HCWs of the first wave, nor among 175 HCWs found positive by PCR during the second wave who were negative during the first wave.

Conclusions

SARS-CoV-2 reinfection was not observed among HCWs, suggesting a protective immunity against reinfection that lasts at least 8 months post infection.

Reduced sensitivity of SARS-CoV-2 variant Delta to antibody neutralization

The SARS-CoV-2 B.1.617 lineage was identified in October 2020 in India^1-5. Since then, it has become dominant in some regions of India and in the UK, and has spread to many other countries⁶. The lineage includes three main subtypes (B1.617.1, B.1.617.2 and B.1.617.3), which contain diverse mutations in the N-terminal domain (NTD) and the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein that may increase the immune evasion potential of these variants. B.1.617.2-also termed the Delta variant-is believed to spread faster than other variants. Here we isolated an infectious strain of the Delta variant from an individual with COVID-19 who had returned to France from India. We examined the sensitivity of this strain to monoclonal antibodies and to antibodies present in sera from individuals who had recovered from COVID-19 (hereafter referred to as convalescent individuals) or who had received a COVID-19 vaccine, and then compared this strain with other strains of SARS-CoV-2. The Delta variant was resistant to neutralization by some anti-NTD and anti-RBD monoclonal antibodies, including bamlanivimab, and these antibodies showed impaired binding to the spike protein. Sera collected from convalescent individuals up to 12 months after the onset of symptoms were fourfold less potent against the Delta variant relative to the Alpha variant (B.1.1.7). Sera from individuals who had received one dose of the Pfizer or the AstraZeneca vaccine had a barely discernible inhibitory effect on the Delta variant. Administration of two doses of the vaccine generated a neutralizing response in 95% of individuals, with titres three- to fivefold lower against the Delta variant than against the Alpha variant. Thus, the spread of the Delta variant is associated with an escape from antibodies that target non-RBD and RBD epitopes of the spike protein.

Long-lasting successful dissemination of resistance to oxazolidinones in MDR Staphylococcus epidermidis clinical isolates in a tertiary care hospital in France

Objectives

Patient- and procedure-related changes in modern medicine have turned CoNS into one of the major nosocomial pathogens. Treatments of CoNS infections are challenging owing to the large proportion of MDR strains and oxazolidinones often remain the last active antimicrobial molecules. Here, we have investigated a long-lasting outbreak (2010-13) due to methicillin- and linezolid-resistant (LR) CoNS (n = 168), involving 72 carriers and 49 infected patients.

Methods

Antimicrobial susceptibilities were tested by the disc diffusion method and MICs were determined by broth microdilution or Etest. The clonal relationship of LR Staphylococcus epidermidis (LRSE) was first determined using a semi-automated repetitive element palindromic PCR (rep-PCR) method. Then, WGS was performed on all cfr-positive LRSE (n = 30) and LRSE isolates representative of each rep-PCR-defined clone (n = 17). Self-transferability of cfr-carrying plasmids was analysed by filter-mating experiments.

Results

This outbreak was caused by the dissemination of three clones (ST2, ST5 and ST22) of LRSE. In these clones, linezolid resistance was caused by (i) mutations in the chromosome-located genes encoding the 23S RNA and L3 and L4 ribosomal proteins, but also by (ii) the dissemination of two different self-conjugative plasmids carrying the cfr gene encoding a 23S RNA methylase. By monitoring linezolid prescriptions in two neighbouring hospitals, we highlighted that the spread of LR-CoNS was strongly associated with linezolid use.

Conclusions

Physicians should be aware that plasmid-encoded linezolid resistance has started to disseminate among CoNS and that rational use of oxazolidinones is critical to preserve these molecules as efficient treatment options for MDR Gram-positive pathogens.

Infectious complications after liver transplantation in human immunodeficiency virus-infected recipients

BACKGROUND

Few studies have investigated infections in human immunodeficiency virus (HIV)-infected liver transplant patients. The aim of this study was to describe the prevalence, time of onset, mortality of infectious complications, other than hepatitis C virus (HCV), and to identify risk factors for their development in a large single-center cohort of HIV-infected liver transplant patients.

METHODS

We studied 109 consecutive HIV-infected patients who underwent liver transplantation (LT) between 1999 and 2010 and followed until December 2012.

RESULTS

The median age was 44 years (interquartile range [IQR] 41-49), 82.6% were male, and the median follow-up was 45.7 months (IQR 14-65). The major indications for LT were HCV cirrhosis (61%) and hepatocellular carcinoma (19%). Forty patients (37%) developed at least 1 infection during the first year after LT. Twenty-eight (26%) patients had an episode of bacteremia. Five (4.6%) patients developed a cytomegalovirus infection. Fungal infections occurred in 5 (4.5%) patients. Four (3.6%) patients developed an HIV-related opportunistic infection. A total of 43 (39.4%) patients died during follow-up. Mortality related to infection occurred in 9 (7%) cases, and 20 (42.5%) patients died because of HCV recurrence. No patients died from opportunistic infections. Model for end-stage liver disease (MELD) score >17 was associated with a 2-fold higher risk (hazard ratio 1.96; 95% confidence interval 1.01-3.80) of developing infectious complications.

CONCLUSIONS

Infections are not a major cause of mortality after LT in HIV patients and opportunistic infections of acquired immunodeficiency syndrome are infrequent. A MELD score >17 increased the risk of developing post-LT infectious complications. Recurrence of HCV infection remains a major cause of mortality.

Link between carbapenemase-producing Enterobacteria carriage and cross-border exchanges: eight-year surveillance in a large French multihospitals institution

Assistance Publique-Hôpitaux de Paris launched a specific strategy to survey and control the spread of emerging multidrug-resistant bacteria such as carbapenemase-producing Enterobacteria (CPE). Among the 63 CPE events that occurred between 2004 and 2011, 87% involved patients with a link with cross-border exchanges, justifying the recommendation to screen and isolate such patients.

Long-term control of vancomycin-resistant Enterococcus faecium at the scale of a large multihospital institution: a seven-year experience

Binary file ES_Abstracts_Final_ECDC.txt matches

Long-term control of vancomycin-resistant Enterococcus faecium at the scale of a large multihospital institution: a seven-year experience

Repeated outbreaks of vancomycin-resistant Enterococcus faecium (VRE) occurred between 2004 and 2010 in Assistance Publique--Hôpitaux de Paris (AP-HP), a 23,000-bed multi-hospital institution. From August 2004 to December 2005, the French guidelines for preventing cross-transmission of multiresistant bacteria were applied. Because the number of VRE cases continued to increase, an institutional control programme was implemented from January 2006 onwards: it foresees stopping transfer of VRE and contact patients, separating VRE and contact patients in distinct cohorts, intervention of a central infection control team to support local teams, and quick application of measures as soon as first VRE cases are identified. Between August 2004 and December 2010, 45 VRE outbreaks occurred in 21 of the 38 AP-HP hospitals, comprising 533 cases. Time series analysis showed that the mean number of cases increased by 0.8 cases per month (95% confidence interval (CI): 0.3 to 1.3, p=0.001) before, and decreased by 0.7 cases per month after implementation of the programme (95% CI: -0.9 to -0.5, p<0.001), resulting in a significant trend change of -1.5 cases per month (95% CI: -2.1 to -0.9, p<0.001). The number of cases per outbreak was significantly lower after implementation of the programme. A sustained and coordinated strategy can control emerging bacteria at the level of a large regional multihospital institution.

Control of a multi-hospital outbreak of KPC-producing Klebsiella pneumoniae type 2 in France, September to October 2009

An outbreak of Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae type 2 was detected in September 2009 in two hospitals in a suburb south of Paris, France. In total, 13 KPC-producing K. pneumoniae type 2 cases (four with infections and nine with digestive-tract colonisations) were identified, including a source case transferred from a Greek hospital. Of the 13 cases, seven were secondary cases associated with use of a contaminated duodenoscope used to examine the source case (attack rate: 41%) and five were secondary cases associated with patient-to-patient transmission in hospital. All isolated strains from the 13 patients: (i) exhibited resistance to all antibiotics except gentamicin and colistin, (ii) were more resistant to ertapenem (minimum inhibitory concentration (MIC) always greater than 4 mg/L) than to imipenem (MIC: 1–8 mg/L, depending on the isolate), (iii) carried the blaKPC-2 and blaSHV12 genes and (iv) had an indistinguishable pulsed-field gel electrophoresis (PFGE) pattern. These cases occurred in three hospitals: some were transferred to four other hospitals. Extended infection control measures implemented in the seven hospitals included: (i) limiting transfer of cases and contact patients to other wards, (ii) cohorting separately cases and contact patients, (iii) reinforcing hand hygiene and contact precautions and (iv) systematic screening of contact patients. Overall, 341 contact patients were screened. A year after the outbreak, no additional case has been identified in these seven hospitals. This outbreak emphasises the importance of rapid identification and notification of emerging highly resistant K. pneumoniae strains in order to implement reinforced control measures.

Extended measures for controlling an outbreak of VIM-1 producing imipenem-resistant Klebsiella pneumoniae in a liver transplant centre in France, 2003-2004

We report the successful control of an outbreak caused by imipenem-resistant VIM-1-producing Klebsiella pneumoniae (IR-Kp) in France. This outbreak occurred in a care centre for abdominal surgery that includes a 15-bed liver intensive care unit and performs more than 130 liver transplantations per year. The index case was a patient with acute liver failure transferred from a hospital in Greece for urgent liver transplantation who was carrying IR-Kp at admission as revealed by routine culture of a rectal swab. Infection control measures were undertaken and included contact isolation and promotion of hand hygiene with alcohol-based hand rub solution. Nevertheless, secondary IR-Kp cases were identified during the six following months from 3 December 2003 to 2 June 2004. From 2 June to 21 October, extended infection control measures were set up, such as cohorting IR-Kp carriers, contact patients and new patients in distinct sections with dedicated staff, limiting ward admission, and strict control of patient transfer. They led to a rapid control of the outbreak. The global attack rate of the IR-Kp outbreak was 2.5%, 13% in liver transplant patients and 0.4% in the other patients in the care centre (p<0.005). Systematic screening for IR-Kp of all patients admitted to the care centre is still maintained to date and no secondary IR-Kp case has been detected since 2 June 2004.

First outbreak of multidrug-resistant Klebsiella pneumoniae carrying blaVIM-1 and blaSHV-5 in a French university hospital

OBJECTIVES

We studied eight imipenem-resistant isolates of Klebsiella pneumoniae involved in an outbreak in a French teaching hospital.

METHODS

The eight isolates were recovered from clinical specimens or rectal swabs. Antibiotic susceptibilities were determined using standard agar diffusion and dilution methods including synergy tests. PFGE was used to study the relatedness of isolates. Genes encoding beta-lactamases were characterized by transfer assays, specific amplification and cloning.

RESULTS

The eight isolates were closely related by PFGE analysis and highly related to a K. pneumoniae strain from Greece. They were highly resistant to beta-lactams, including aztreonam and imipenem (MIC > or =32 mg/L), and were positive by the imipenem-EDTA disc synergy test. Isolates were also resistant to aminoglycosides, newer quinolones and sulfamethoxazole, and showed an intermediate level of resistance to tetracycline. VIM-1 and SHV-5 beta-lactamases were revealed in all isolates by PCR. The analysis of plasmid contents of Escherichia coli DH10B electroporants expressing the VIM-1 beta-lactamase or the SHV-5 beta-lactamase confirmed that the two enzymes were coded by two different plasmids. The bla(VIM-1) gene was part of a class 1 integron that also included aac6, dhfrI and aadA genes and was similar to those reported from strains isolated in Greece.

CONCLUSIONS

This study confirms the potential risk of spread of multiresistant bacteria with international transfer of patients.

Intranasal immunization with protein-linked phosphorylcholine protects mice against a lethal intranasal challenge with streptococcus pneumoniae

Immunization against phosphorylcholine (PC) linked to a protein protects mice against Streptococcus pneumoniae when used parenterally, and against Salmonella typhimurium when used orally after entrapment in D,L-Lactide-co-Glycolide microspheres. Here, we immunized BALB/c mice intranasally with a serotype 3 S. pneumoniae strain. Immunization was followed by a rise in anti-PC IgA and IgG titers in serum and in pulmonary secretions, but not by any rise in anti ds-DNA antibody nor any glomerular Ig deposition. The survival rates were 91 and 76% in the two groups of mice, respectively. These rates were significantly higher than those in control mice immunized intranasally either with Thyr loaded in microspheres (0%), blank microspheres (22%), free Thyr (17%), and saline (18%). This demonstrates that the mucosal route is effective for vaccination against S. pneumoniae pneumonia with PC linked to a protein carrier. It constitutes another important step forward in the development of the concept that PC can be used as a mucosal immunogen for protection against the different diseases caused by PC-bearing bacteria.