Breakthrough invasive fungal infection among patients with haematologic malignancies: A national, prospective, and multicentre study

OBJECTIVES

We describe the current epidemiology, causes, and outcomes of breakthrough invasive fungal infections (BtIFI) in patients with haematologic malignancies.

METHODS

BtIFI in patients with ≥ 7 days of prior antifungals were prospectively diagnosed (36 months across 13 Spanish hospitals) according to revised EORTC/MSG definitions.

RESULTS

121 episodes of BtIFI were documented, of which 41 (33.9%) were proven; 53 (43.8%), probable; and 27 (22.3%), possible. The most frequent prior antifungals included posaconazole (32.2%), echinocandins (28.9%) and fluconazole (24.8%)-mainly for primary prophylaxis (81%). The most common haematologic malignancy was acute leukaemia (64.5%), and 59 (48.8%) patients had undergone a hematopoietic stem-cell transplantation. Invasive aspergillosis, principally caused by non-fumigatus Aspergillus, was the most frequent BtIFI with 55 (45.5%) episodes recorded, followed by candidemia (23, 19%), mucormycosis (7, 5.8%), other moulds (6, 5%) and other yeasts (5, 4.1%). Azole resistance/non-susceptibility was commonly found. Prior antifungal therapy widely determined BtIFI epidemiology. The most common cause of BtIFI in proven and probable cases was the lack of activity of the prior antifungal (63, 67.0%). At diagnosis, antifungal therapy was mostly changed (90.9%), mainly to liposomal amphotericin-B (48.8%). Overall, 100-day mortality was 47.1%; BtIFI was either the cause or an essential contributing factor to death in 61.4% of cases.

CONCLUSIONS

BtIFI are mainly caused by non-fumigatus Aspergillus, non-albicans Candida, Mucorales and other rare species of mould and yeast. Prior antifungals determine the epidemiology of BtIFI. The exceedingly high mortality due to BtIFI warrants an aggressive diagnostic approach and early initiation of broad-spectrum antifungals different than those previously used.

Impact of the COVID-19 Pandemic on the Clinical Profile of Candidemia and the Incidence of Fungemia Due to Fluconazole-Resistant Candida parapsilosis

Severely ill COVID-19 patients are at high risk of nosocomial infections. The aim of the study was to describe the characteristics of candidemia during the pre-pandemic period (January 2019−February 2020) compared to the pandemic period (March 2020−September 2021). Antifungal susceptibilities were assessed using the EUCAST E.Def 7.3.2 broth dilution method. Fluconazole-resistant C. parapsilosis isolates (FRCP) were studied for sequencing of the ERG11 gene. The incidence of candidemia and C. parapsilosis bloodstream infection increased significantly in the pandemic period (p = 0.021). ICU admission, mechanical ventilation, parenteral nutrition and corticosteroids administration were more frequent in patients with candidemia who had been admitted due to COVID-19. Fifteen cases of FRCP fungemia were detected. The first case was recorded 10 months before the pandemic in a patient transferred from another hospital. The incidence of FRCP in patients admitted for COVID-19 was 1.34 and 0.16 in all other patients (p < 0.001). ICU admission, previous Candida spp. colonization, arterial catheter use, parenteral nutrition and renal function replacement therapy were more frequent in patients with candidemia due to FRCP. All FRCP isolates showed the Y132F mutation. In conclusion, the incidence of candidemia experienced an increase during the COVID-19 pandemic and FRCP fungemia was more frequent in patients admitted due to COVID-19.

Unreliability of Clinical Prediction Rules to Exclude without Echocardiography Infective Endocarditis in Staphylococcus aureus Bacteremia

BACKGROUND

It is unclear whether the use of clinical prediction rules is sufficient to rule out infective endocarditis (IE) in patients with Staphylococcus aureus bacteremia (SAB) without an echocardiogram evaluation, either transthoracic (TTE) and/or transesophageal (TEE). Our primary purpose was to test the usefulness of PREDICT, POSITIVE, and VIRSTA scores to rule out IE without echocardiography. Our secondary purpose was to evaluate whether not performing an echocardiogram evaluation is associated with higher mortality.

METHODS

We conducted a unicentric retrospective cohort including all patients with a first SAB episode from January 2015 to December 2020. IE was defined according to modified Duke criteria. We predefined threshold cutoff points to consider that IE was ruled out by means of the mentioned scores. To assess 30-day mortality, we used a multivariable regression model considering performing an echocardiogram as covariate.

RESULTS

Out of 404 patients, IE was diagnosed in 50 (12.4%). Prevalence of IE within patients with negative PREDICT, POSITIVE, and VIRSTA scores was: 3.6% (95% CI 0.1-6.9%), 4.9% (95% CI 2.2-7.7%), and 2.2% (95% CI 0.2-4.3%), respectively. Patients with negative VIRSTA and negative TTE had an IE prevalence of 0.9% (95% CI 0-2.8%). Performing an echocardiogram was independently associated with lower 30-day mortality (OR 0.24 95% CI 0.10-0.54, p = 0.001).

CONCLUSION

PREDICT and POSITIVE scores were not sufficient to rule out IE without TEE. In patients with negative VIRSTA score, it was doubtful if IE could be discarded with a negative TTE. Not performing an echocardiogram was associated with worse outcomes, which might be related to presence of occult IE. Further studies are needed to assess the usefulness of clinical prediction rules in avoiding echocardiographic evaluation in SAB patients.

Effective definition of low humoral response to Clostridioides difficile infection

BACKGROUND

Determination of the humoral response to Clostridioides difficile (CD) toxins could be of great value in the management of patients with CD infection (CDI).

METHODS

A prospective study was conducted on the clinical characteristics and humoral response in patients with CDI. Determination of ELISA IgG CD anti-toxin B (tgcBiomics, Germany) was performed. The following dilutions were planned for each patient, 1:100, 1: 200, 1: 400, 1: 800: 1: 1600. A significant concentration of antibody was considered to be present in each dilution if an optical density 0.2 units higher than the negative control of the technique was evident.

RESULTS

Eighty-five patients were included during the study period, November 2018-February 2020. The median age was 73 years (interquartile range: 62.5-85 years), with female predominance (45 patients, 52.9%). Thirty-nine patients (45.9%) had a severe infection. Seven patients (8.2%) had suffered an episode of CDI in the previous three months. Seventeen patients (20%) had one or more recurrent episodes during the three-month follow-up: No patient died during admission or required surgery for severe-complicated infection. The incidence of recurrence in patients with no antibody detected at 1:400 dilution was 25.4% (16 patients) while it was 4.3% (one patient) in patients with antibody present at that dilution (p = 0.03). Liver cirrhosis was associated with higher humoral response against CD.

CONCLUSIONS

Antibodies IgG CD anti-toxin B detection at a dilution of 1:400, using a B ELISA technique, effectively identified patients at increased risk of recurrence. This information could help assist in the management of patients.

A retrospective validation of different scores of guideline adherence and infectious diseases consultation on candidaemia: The higher, the better

BACKGROUND

Recently, several scores to quantify compliance with the guidelines in candidaemia management (EQUAL, GEMICOMED, Valerio) have been developed. Evidence supporting the association of these scores to the prognosis is scarce. We aim to evaluate the performance of these candidaemia guideline adherence scores to predict candidaemia outcome.

METHODS

We recorded retrospectively data from candidaemia episodes (January 2017-December 2018). We analysed adherence to guidelines for candidaemia management according to EQUAL, GEMICOMED and Valerio scores, and we correlated those to outcome.

RESULTS

Fifty-four first episodes of candidaemia were retrieved. Five patients who died in the first 48 hours after blood cultures were not included. Thirty-day mortality in evaluable patients was 18.4%. Median adherence to guidelines according to EQUAL score was 17 (interquartile range [IQR]: 15-19), and according to GEMICOMED was 86% (IQR: 72.5%-100%). According to Valerio score, adequacy of antifungal prescription was 8.5/10 (SD: 1.9). A cut-off of ≥17 for EQUAL or compliance >70% for GEMICOMED was associated with inferior 30-day mortality (7.1% vs 33.3%, P = .028 and 7.9% vs 54.5%, P = .002, respectively). Infectious diseases (ID) evaluated cases obtained a better EQUAL score (>17; 82.1% vs 42.9%, P = .006), had inferior 30-day mortality (9.4% vs 35.3%, P = .049) and a better antifungal prescription adequacy (Valerio score 9.0 vs 7.5, P = .011).

CONCLUSION

Adherence to guidelines for candidaemia management evaluated by means of EQUAL and GEMICOMED score was associated with a decreased 30-day mortality. Adequacy of antifungal prescription can be ameliorated. ID consultation improved guideline adherence and was associated with decreased 30-day mortality.

Hospital-acquired infective endocarditis during Covid-19 pandemic

BACKGROUND

The COVID pandemic has had a major impact on healthcare in hospitals, including the diagnosis and treatment of infections. Hospital-acquired infective endocarditis (HAIE) is a severe complication of medical procedures that has shown a progressive increase in recent years.

OBJECTIVES

To determine whether the incidence of HAIE during the first two months of the epidemic (March-April 2020) was higher than previously observed and to describe the clinical characteristics of these cases. The probability of the studied event (HAIE) during the study period was calculated by Poisson distribution.

RESULTS

Four cases of HAIE were diagnosed in our institution during the study period. The incidence of HAIE during the study period was 2/patient-month and 0.3/patient-month during the same calender months in the previous 5 years (p=0.033). Two cases presented during admission for COVID-19 with pulmonary involvement treated with methylprednisolone and tocilizumab. The other two cases were admitted to the hospital during the epidemic. All cases underwent central venous and urinary catheterization during admission. The etiology of HAIE was Enterococcus faecalis (2 cases), Staphylococcus aureus and Candida albicans (one case each). A source of infection was identified in three cases (central venous catheter, peripheral venous catheter, sternal wound infection, respectively). One patient was operated on. Two patients died during hospital admission.

CONCLUSIONS

The incidence of HAIE during COVID-19 pandemic in our institution was higher than usual. In order to reduce the risk of this serious infection, optimal catheter care and early treatment of every local infection should be prioritized during coronavirus outbreaks.

Epidemiology and clinical of infections and colonizations caused by Enterobacterales producing carbapenemases in a tertiary hospital

Objetivos

Describir la epidemiologia de las Enterobacterias portadoras de carbapenemasas (EPC) en un hospital de tercer nivel.

Material y métodos

Estudio observacional retrospectivo, se incluyeron todos los pacientes con muestra positiva para EPC atendidos en hospitalización o en el servicio de Urgencias, entre el 1 Enero de 2014 y el 31 de Diciembre de 2016.

Resultados

Se incluyeron 272 pacientes (316 muestras): 155 (57%) varones. Media de edad de 70,4 años (IC 95% 68,2 -72,7). Media del índice de Charlson 3,6 (IC95% 3,4-3,8). En el 63,2% la adquisición fue nosocomial, en el 35,3% fue asociada a cuidados sanitarios (ACS). Presentaron infección el 55,1%, siendo la más frecuente la infección del tracto urinario (ITU) (58,7%). Las especies más frecuentes fueron Klebsiella pneumoniae (62,7%) y Enterobacter cloacae (10,1%). Los tipos de carbapenemasa más frecuente fueron OXA-48 (53,8%) y VIM (43%). La adquisición nosocomial se asoció con el género masculino, trasplante, inmunosupresión, ingreso en Unidad de Cuidados Intensivos (UCI) o Servicio Quirúrgico, tratamiento antibiótico previo, Enterobacter, VIM, infecciones respiratorias e intraabdominales. La adquisición ACS se asoció con mayor edad y comorbilidad, procedencia de residencia, sondaje vesical, mayor número de procedimientos ambulatorios, ingreso hospitalario previo, K. pneumoniae y E. coli, OXA–48, coproducción de betalactamasas de espectro extendido, ITU y sepsis.

Conclusiones

Los pacientes que adquieren la EPC en residencias presentan frecuentemente infección. Los pacientes con adquisición nosocomial se colonizan por EPC en la UCI, en relación a procedimientos invasivos y trasplante. Esta población presenta mayor mortalidad por desarrollar infecciones respiratorias por EPC.

First national survey of the diagnosis of Helicobacter pylori infection in Clinical Microbiology Laboratories in Spain

INTRODUCTION

The aim of this study was to know, through a national survey, the methods and techniques used for the diagnosis of Helicobacter pylori (Hp) in the different Clinical Microbiology Services/Laboratories in Spain, as well as antibiotic resistance data.

METHODS

The survey requested information about the diagnostic methods performed for Hp detection in Clinical Microbiology laboratories, including serology, stool antigen, culture from gastric biopsies, and PCR. In addition, the performance of antibiotic susceptibility was collected. Data on the number of samples processed in 2016, positivity of each technique and resistance data were requested. The survey was sent by email (October-December 2017) to the heads of 198 Clinical Microbiology Laboratories in Spain.

RESULTS

Overall, 51 centers from 29 regions answered the survey and 48/51 provided Hp microbiological diagnostic testing. Concerning the microbiological methods used to diagnose Hp infection, the culture of gastric biopsies was the most frequent (37/48), followed by stool antigen detection (35/48), serology (19/48) and biopsy PCR (5/48). Regarding antibiotic resistance, high resistance rates were observed, especially in metronidazole and clarithromycin (over 33%).

CONCLUSION

Culture of gastric biopsies was the most frequent method for detection of Hp, but the immunochromatographic stool antigen test was the one with which the largest number of samples were analyzed. Nowadays, in Spain, it concerns the problem of increased antibiotic resistance to 'first-line' antibiotics.

Impact of Pseudomonas aeruginosa bacteraemia in a tertiary hospital: Mortality and prognostic factors

BACKGROUND AND OBJECTIVES

Pseudomonas aeruginosa bacteraemia is associated with a very high mortality, conditioned by comorbidity, source, severity of the episode and lack of adequate treatment. The aim of the study is to know the mortality and prognostic factors of bacteraemia by P.aeruginosa in our hospital.

PATIENTS AND METHODS

We conducted a retrospective study of P.aeruginosa bacteraemia detected between 2009 and 2014. Epidemiological, clinical and microbiological characteristics were described. A risk factor analysis for mortality was performed.

RESULTS

We analysed 110 episodes of bacteraemia, which was more frequent in men of advanced age and with a history of hospitalisation, comorbidity and immunosuppression. Most of the bacteraemias were secondary (mainly of respiratory or urinary source) and led to a significant clinical deterioration. The presence of antibiotic resistance was very high, with 27.3% of multiresistant strains. Empirical treatment was adequate in 60.0% and 92.3% for definite treatment. Overall mortality was 37.3% and attributable mortality was 29.1%. The most important prognostic factors were Charlson index ≥3, history of haematologic malignancy, neutropenia and previous use of corticosteroids, source of bacteraemia, Pitt index ≥4, renal insufficiency, adequate definite treatment, empiric treatment with piperacillin/tazobactam in severe episodes and focus control.

CONCLUSION

P.aeruginosa bacteraemia is associated with a very high mortality, possibly more related to previous comorbidity and severity of the episode than to the treatment chosen. However, the main goal in management remains to optimise treatment, including focus control.

Epidemiology and prognosis of candidaemia in elderly patients

The aim of the study was to analyse the epidemiology and prognosis of candidaemia in elderly patients. We performed a comparison of clinical presentation of candidaemia according to age and a study of hazard factors within a prospective programme performed in 29 hospitals. One hundred and seventy-six episodes occurred in elderly patients (>75 years), 227 episodes in middle-aged patients (61-75 years) and 232 episodes in younger patients (16-60 years). Central venous catheter, parenteral nutrition, neutropenia, immunosuppressive therapy and candidaemia caused by Candida parapsilosis were less frequent in elderly patients. These patients received inadequate antifungal therapy (57.3%) more frequently than middle-aged and younger patients (40.5% P < .001). Mortality during the first week (20%) and 30 days (42%) was higher in elderly patients. The variables independently associated with mortality in elderly patients during the first 7 days were acute renal failure (OR: 2.64), Pitt score (OR: 1.57) and appropriate antifungal therapy (OR: 0.132). Primary candidaemia (OR: 2.93), acute renal failure (OR: 3.68), Pitt score (OR: 1.38), appropriate antifungal therapy (OR: 0.3) and early removal of the central catheter (OR: 0.47) were independently associated with 30-day mortality.In conclussion, inadequate antifungal treatment is frequently prescribed to elderly patients with candidaemia and is related with early and late mortality.

Risk factors, clinical presentation and prognosis of mixed candidaemia: a population-based surveillance in Spain

The low incidence of mixed candidaemia (MC) may have precluded a better knowledge of its clinical presentation. The aim of the study was to analyse the risk factors, clinical presentation and prognosis of MC episodes. A comparison between MC and monomicrobial candidaemia within a prospective programme on candidaemia was performed in 29 hospitals between April 2010 and May 2011. In fifteen episodes of candidaemia corresponding to 15 patients, out of 752, two species of Candida (1.9%) were isolated. MC was more frequent in patients with HIV infection (12%, P = 0.038) and those admitted due to extensive burns (23%, P = 0.012). The Candida species most frequently identified in MC were C. albicans 12 patients (40%), C. glabrata seven patients (23.3%) and C. parapsilosis six patients (20%). Early mortality was higher (nine patients, 60%) in patients with MC than in patients with MMC (223 patients, 30.3%, P = 0.046). In conclusion, MC was was independently associated with increased mortality even after considering other prognostic factors. MC is an infrequent event that is more common in HIV infection and in patients suffering from burns, and is associated with increased mortality.

Risk factors for Clostridium difficile diarrhea in patients with inflammatory bowel disease

BACKGROUND

Despite the growing incidence of Clostridium difficile diarrhea (CCD) in patients with inflammatory bowel disease (IBD), little is known about the associated risk factors.

METHOD

A retrospective study comparing cases of CCD in patients with IBD to IBD carriers who did not develop CCD. A comparison was also made with patients who developed CCD but did not suffer IBD.

RESULTS

Three cases (20%) with IBD and CCD had received antibiotics during the previous three months versus none of the controls (IBD without CCD, p = 0.22). Ten cases (67%) received treatment with proton pump inhibitors (PPIs) versus 2 (13%) in the control group (IBD without CCD, p = 0.001). Seven cases underwent colonoscopy and pseudomembranes were seen in one (14%). Fourteen (93%) patients demonstrated a favourable response to metronidazole. Patients with IBD and CCD presented with younger age (36 ± 10 years), a higher degree of community-acquired infection (13 patients, 87%), immunosuppressive treatment (7 patients, 47%) and less patients had received previous antibiotic treatment (3 patients, 20%) than those with CCD without IBD. The proportion of patients who received treatment with PPIs was similar (66% and 80%, respectively p = 0.266).

CONCLUSIONS

CCD in IBD carriers affects younger patients, the majority are community acquired (less nosocomial) and it is more related to previous treatment with PPIs than with the antibiotic treatment. Clinical evolution is also favourable.

Antimicrobial stewardship in patients recently transferred to a ward from the ICU

PURPOSE

Inappropriate use of antibiotics is an important health problem that is related to increasing bacterial resistance. Despite its relevance, many health institutions assign very limited resources to improving prescribing practices. An antimicrobial stewardship programme (APS) centred on patients discharged from the ICU could efficiently undertake this task.

METHODS

During this six month study the main activity was performing a programmed review of antimicrobial prescriptions in patients transferred to the ward from the ICU. In the case of inadequate antimicrobial treatment, a recommendation was included in the medical record.

RESULTS

A total of 437 antimicrobial prescriptions for 286 patients were revised during a six month period. In all, 271 prescriptions (62%) were considered inappropriate in 183 patients. The most common reasons for inappropriateness were treating unconfirmed infection (43%), inadequate antimicrobial coverage (34%) and intravenous administration when the oral route was feasible (11%). Proposed recommendations were addressed in 212 cases (78%). There was no significant difference in adherence with respect to the type of recommendation (p=0.417). There was a 5% lower use of antibiotics during the year the study was conducted compared to the previous one.

CONCLUSIONS

ASPs centred on patients discharged from the ICU may be an efficient strategy to ameliorate antimicrobial use in hospitals.

Contamination of liquid soap for hospital use with Raoultella planticola

This article reports the contamination of a batch of liquid soap for hospital use with Raoultella planticola. The micro-organism was first identified as Klebsiella pneumoniae due to the inability of automated systems to characterize this species. There is a need to strengthen the inspection of cosmetic products to be used in the hospital setting. It is recommended that hospitalized patients at the highest risk of infection should use antimicrobial soaps for personal hygiene. The incidence of infections due to R. planticola is unknown as it is usually misclassified as Klebsiella spp. by automated systems.

Gonococcal endocarditis: a case report and review of the literature

A 59-year-old Caucasian male presented with progressive dyspnea, arthralgias and fever for three days. A diastolic regurgitation murmur was detected in the aortic area. A transesophageal echocardiograph showed several vegetations and severe aortic regurgitation. Blood cultures yielded Neisseria gonorrhoeae beta-lactamase negative. The patient had not noticed any urogenital discomfort or urethral discharge. The patient successfully underwent surgery for septal abscess debridement. The patient received ceftriaxone 2 g bid for eight weeks and the clinical follow-up was uneventful. The review of the literature revealed a total of the 38 additional cases reported between 1980 and the present. The majority of the patients were young, male and with native valve involvement. There has been a clear tendency for left-sided valve involvement (especially in the aortic valve). All valve cultures were reported negative despite, in most cases, the marked tissue destruction. Polymerase chain reaction was performed in two patients and positive results were shown in both. Cultures of exudates from other locations were negative in most cases. One striking fact is the high proportion of patients who underwent surgery (72 %). Information regarding antibiotic sensitivity was available in 28 cases, with penicillin resistance reported in six patients (21 %) and intermediate sensitivity in four patients (14 %). Resistance to ciprofloxacin was reported in two cases (7 %). A rapid increase and distribution of isolates resistant to third generation cephalosporins have been recently detected. The mortality is high, particularly taking into account that most were young patients who had not presented previous heart disease.

Emergence of OXA-48-producing Klebsiella pneumoniae and the novel carbapenemases OXA-244 and OXA-245 in Spain

OBJECTIVES

To describe the molecular and population-level characterization of a selected group of OXA-48-like-producing Klebsiella pneumoniae isolates collected in Spain between January 2011 and May 2012.

METHODS

During the study period, 151 OXA-48-like-producing K. pneumoniae isolates were collected from 10 hospitals in six different Spanish regions. From these, a representative sample of 21 isolates that caused hospital outbreaks and single infections was selected for further in-depth analysis. Molecular epidemiology was investigated using PFGE and multilocus sequence typing (MLST). Resistance genes were characterized by PCR and sequencing. Plasmids carrying bla(OXA-48-like) were studied by PFGE with S1 nuclease digestion.

RESULTS

All 21 isolates had ertapenem MICs ≥ 1 mg/L, but 47.6% remained susceptible to imipenem and meropenem; bla(OXA-48) was identified in 19 isolates (90.5%) and the novel bla(OXA-244) and bla(OXA-245) genes were detected in 1 isolate each. With one exception, all isolates that contained bla(OXA-48-like) also contained bla(CTX-M-15). PFGE typing revealed six clusters comprising isolates that belonged to MLST types ST11, ST16, ST392, ST405, ST437 and ST663, respectively. Two main clusters were identified: PFGE cluster 1 (12 isolates, belonging either to ST405 or ST663, from seven hospitals), and PFGE cluster 2 (4 ST16 isolates from two hospitals). Six of seven donor isolates conjugated successfully; bla(OXA-48-like) (but not bla(CTX-M-15)) was carried on ≈ 60 kb Inc L/M plasmids.

CONCLUSIONS

Multidrug-resistant K. pneumoniae producing OXA-48-like carbapenemase are emerging as important pathogens in Spain due to intra- and inter-hospital, clonal and non-clonal dissemination.

[Microbiological diagnosis of intra-abdominal infections]

Intra-abdominal infections represent a large and wide group of diseases which include intra- and retro-peritoneal infections. Some of them could be defined as uncomplicated, where the infectious process is limited to the organ or tissue of origin (appendicitis, diverticulitis, cholecystitis…). Complications occur when the infection spreads to the peritoneum, triggering localised peritonitis and abdominal abscesses. Most intra-abdominal infections are due to perforation or inflammation of the intestinal wall. The microorganisms that cause these infections come from the gastrointestinal flora, and therefore produce polymicrobial infections mixed with a predominance of anaerobic bacteria. Microbiological diagnosis is essential to determine the aetiology and the susceptibility of antimicrobial agents of the microorganism involved, especially in nosocomial infections or in community infections in predisposed patients due to increasing bacterial resistance to antimicrobial agents, multidrug resistance and fungal involvement. Despite the advances in microbiological diagnosis, in the case of intra-abdominal infections it still remains direct, being based on stains and cultures, the most notable progress is the introduction of mass spectrometry (MALDI-TOF) for the rapid identification of the pathogens involved. This review will provide recommendations on the collection, transport and microbiological processing of clinical specimens. Comments on the pathogenesis, clinical and microbiological diagnosis of peritonitis primary, secondary, tertiary and peritonitis (and other infections) associated with peritoneal dialysis, intra-abdominal abscesses (intraperitoneal, retroperitoneal and visceral), biliary tract infections, appendicitis and diverticulitis are also presented.

[Postoperative recurrence of subdural empyema]

We present a case of recurrent subdural post-surgical empyema by Proprionibacterium acnes after a first drained empyema in which no microbiological diagnosis was reached. P. acnes is a gram-positive anaerobic organism which is part of the saprophytic flora of the skin and others parts of the body. However, it can cause infections, as in the central nervous system, especially post-surgical infections in which can be the second more frequent organism after Staphylococcus aureus. P. acnes grows slowly and shows better growth in liquid anaerobic media. It is usually resistant to metronidazol and sensitive to penicillin. In postoperative central nervous system infections we must take into account the possibility of this organism, process the sample properly and keep touch with the Microbiology Department.

[Postsurgical meningitis. Differential characteristics of aseptic postsurgical meningitis]

BACKGROUND

Postsurgical meningitis is a rare complication that is accompanied by an increase of hospital stay and high mortality. Some of these cases are not due to a true infection but due to an aseptic inflammation of the meninges denominated aseptic postsurgical meningitis (APSM). Proper identification of these cases would allow better use of antimicrobial drugs.

METHODS

A retrospective study of patients with postsurgical meningitis in a universitary hospital for 14 years. We describe the clinical characteristics of patients with postsurgical bacterial meningitis (PBM) compared to those of patients with APSM.

RESULTS

During the studied period 35 patients (71%) with PBM and 14 patients (29%) with (APSM) were identified. The mean age of patients with PBM was similar to that of patients with APSM. There was a male predominance in the group of PBM (71%) compared with patients with APSM (36%, p = 0.020). Patients with intracranial hemorrhage tended to present more cases of APSM (64%) than of PBM (34%, p = 0.055). Patients undergoing posterior fossa craniotomy (p = 0.092) and those receiving steroids (p = 0.051) showed a greater tendency to suffer APSM. It was also noted a trend towards present PBM in patients who had suffered an infection in the previous month (p = 0.072). There were seven patients with PBM (20%) with a cell count above 5000 cells/mm3 in CSF, values not found in any patients with APSM. No differences were detected in the glycorrachia and proteinorrachia between the two groups. The most common bacteria isolated were coagulase negative Staphylococcus and S. aureus. In 5 patients (14%) non fermenting gram-negative bacillus (Pseudomonas aeruginosa and Acinetobacter spp) were isolated. There were no deaths attributed to any type of postsurgical meningitis.

CONCLUSION

Patients admitted for brain haemorrhage, undergoing posterior fossa surgery or receiving steroids tend to develop APSM. A CSF cell count above 5000 cells / mm3 strongly suggests MBP.

Evolution of the antimicrobial resistance of Pseudomonas aeruginosa in Spain: second national study (2003)

The second national prevalence study of Pseudomonas aeruginosa has been carried out in Spain. A total of 1250 clinical isolates of P. aeruginosa were collected from 127 hospitals in 1 week in 2003 and the resistance data gathered from the isolates was compared with those of the first study in 1998 (1014 isolates from 136 hospitals). Antimicrobial susceptibility testing was performed in both studies in the same laboratory. The most active antimicrobials were piperacillin, piperacillin-tazobactam, and amikacin (< or =10% resistant) and resistance to these antimicrobials did not change over the time. The least active were ofloxacin and gentamicin (> or =30% resistant). From 1998 to 2003, resistance increased significantly to ciprofloxacin (23% vs. 28%, respectively, p=0.015); ofloxacin (30% vs. 37%, p=0.002); imipenem (14% vs. 18%, p=0.017) and meropenem (8% vs. 13%, p <0.001). Resistance to aztreonam (23%), ceftazidime (16%), cefepime (20%), ticarcillin (13%) and tobramycin (11%) remained stable. Isolates from inpatients were significantly more resistant than those from outpatients to all antimicrobials, with the exception of fluoroquinolones and aminoglycosides (p <0.01). Isolates from outpatients were significantly more resistant to these two groups (p <0.05) than to other antimicrobials. In Spain, from 1998 to 2003, the susceptibility pattern of P. aeruginosa to antimicrobial agents has changed. Isolates have become significantly more resistant to fluoroquinolones and carbapenems. However, resistance to beta-lactams and aminoglycosides remains stable.