The Magnificent Seven: Seven good publications in infectious disease

The world of infectious diseases, for various reasons, before and after the COVID-19 pandemic, capture the attention of the scientific community, either due to the epidemiological data of various microbial agents that are emerging, due to the implementation with successful results of new diagnostic strategies or due to the appearance of new therapeutic options, which encourage healthcare workers to continue on the front line. Topics such as antimicrobial resistance, S. aureus bacteremia, clostridioides difficile, short treatments for tuberculosis, prosthetic joint infection or invasive fungal infections are included. In this article, we want to highlight, among many others, seven recently published articles that deserve our attention, full of useful information to keep us updated.

Mycoplasma genitalium and sexually transmitted infections: evidences and figures in a tertiary hospital

Introduction

Mycoplasma genitalium is an emerging cause of sexually transmitted infections (STIs) and has been implicated in non-gonococcal urethritis in men and cervicitis in woman. The aim of this study is determinate the incidence and pathogenicity of M. genitalium within the diagnosis of STIs detected from clinical samples in a third level hospital.

Material and methods

A total of 8,473 samples from endocervix, urethra, vagina, rectum and others were processed applying Allpex STI Essential Assay. More than 190 records were reviewed to determinate M. genitalium pathogenicity.

Results

M. genitalium was detected in a rate 2.8%. Co-infections were detected in 20% of the patients.

Conclusions

M. genitalium is considered a STI emerging pathogen thanks to the renewal of multiplex-PCR tests although with a low incidence in our approach. Emerging from our experience and the institutional recommendations both detection of acid nucleic techniques (NAATs) and gonococcal culture might be implemented accurately and coexist to adequate prescriptions.

Clostridioides difficile infection in a long-term convalescence hospital: A real tale of pitfalls and outdated therapy

Objective

The aim of the study was to know the characteristics and risk factors of Clostridioides difficile infection (CDI) in a long-term hospital is key to improve its management.

Material and methods

Retrospective study with 37 patients, along 43 months. We describe demographic variables, clinical data, time to diagnosis, treatment, and evolution.

Results

Analysis of 46 episodes (37 patients, mean age=82.2 years). 77.8% were absolutely dependent, 41.7% had chronic kidney disease, 64.9% had received antibiotics in the previous three months, 40.5% received antibiotics at diagnosis. It was the first episode in 78.4%, and first recurrence in 21.6%. Therapy was started in the first 24 hours after diagnosis in 89.2%, mostly metronidazole. 83.3% recovered, 3 patients died from CDI, diagnosis was registered in the discharge report in 91.1%.

Conclusions

Previous antibiotic therapy, high grade of dependency and renal failure were the main risk factors. There is room for improvement in CDI management at our hospital.

Linezolid for therapy of Staphylococcus aureus meningitis: a cohort study of 26 patients

BACKGROUND

Linezolid has good penetration to the meninges and could be an alternative for treatment of Staphylococcus aureus meningitis. We assessed the efficacy and safety of linezolid therapy for this infection.

METHODS

Retrospective multicenter cohort study of 26 adults treated with linezolid, derived from a cohort of 350 cases of S. aureus meningitis diagnosed at 11 university hospitals in Spain (1981-2015).

RESULTS

There were 15 males (58%) and mean age was 47.3 years. Meningitis was postoperative in 21 (81%) patients. The infection was nosocomial in 23 (88%) cases, and caused by methicillin-resistant S. aureus in 15 cases and methicillin-susceptible S. aureus in 11. Linezolid was given as empirical therapy in 10 cases, as directed therapy in 10, and due to failure of vancomycin in 6. Monotherapy was given to 16 (62%) patients. Median duration of linezolid therapy was 17 days (IQR 12-22 days) with a daily dose of 1,200 mg in all cases. The clinical response rate to linezolid was 69% (18/26) and microbiological response was observed in 14 of 15 cases evaluated (93%). Overall 30-day mortality was 23% and was directly associated with infection in most cases. When compared with the patients of the cohort, no significant difference in mortality was observed between patients receiving linezolid or vancomycin for therapy of methicillin-resistant S. aureus meningitis (9% vs. 20%; p = .16) nor between patients receiving linezolid or cloxacillin for therapy of methicillin-susceptible S. aureus meningitis (20% vs 14%; p = .68). Adverse events appeared in 14% (3/22) of patients, but linezolid was discontinued in only one patient.

CONCLUSIONS

Linezolid appears to be effective and safe for therapy of S. aureus meningitis. Our findings showed that linezolid may be considered an adequate alternative to other antimicrobials in meningitis caused by S. aureus.

Comparing Two Automated Techniques for the Primary Screening-Out of Urine Culture

Urinary tract infection is the most common human infection with a high morbidity. In primary care and hospital services, conventional urine culture is a key part of infection diagnosis but results take at least 24 h. Therefore, a rapid and reliable screening method is still needed to discard negative samples as quickly as possible and to reduce the laboratory workload. In this aspect, this study aims to compare the diagnostic performance between Sysmex UF-1000i and FUS200 systems in comparison to urine culture as the gold standard. From March to June 2016, 1,220 urine samples collected at the clinical microbiology laboratory of the “Miguel Servet” hospital were studied in parallel with both analysers, and some technical features were evaluated to select the ideal equipment. The most balanced cut-off values taking into account bacteria or leukocyte counts were 138 bacteria/μL or 119.8 leukocyte/μL for the UF-1000i (95.3% SE and 70.4% SP), and 5.7 bacteria/μL or 4.3 leukocyte/μL for the FUS200 (95.8% SE and 44.4% SP). The reduction of cultured plates was 37.4% with the FUS200 and 58.3% with the UF-1000i. This study shows that both techniques improve the workflow in the laboratory, but the UF-1000i has the highest specificity at any sensitivity and the FUS200 needs a shorter processing time.

Staphylococcus aureus meningitis in adults: A comparative cohort study of infections caused by meticillin-resistant and meticillin-susceptible strains

BACKGROUND

Staphylococcus aureus meningitis is an uncommon nosocomial infection usually associated with neurosurgical procedures, but spontaneous infections may occasionally appear.

AIMS

To compare the features of meningitis caused by meticillin-resistant (MRSA) and meticillin-susceptible (MSSA) S. aureus and examine the prognostic factors for mortality, including MRSA infection and combined antimicrobial therapy.

METHODS

Retrospective cohort study of 350 adults with S. aureus meningitis admitted to 11 hospitals in Spain (1981-2015). Logistic regression and propensity score matching were used to analyse prognostic factors.

RESULTS

There were 118 patients (34%) with MRSA and 232 (66%) with MSSA. Postoperative infection (91% vs 73%) and nosocomial acquisition (93% vs 74%) were significantly more frequent in MRSA than in MSSA meningitis (P < 0.001). Combined therapy was given to 118 (34%) patients. Overall 30-day mortality rate was 23%. On multivariate analysis, mortality was associated with severe sepsis or shock (odds ratio (OR) 9.9, 95% confidence interval (CI) 4.5-22.0, P < 0.001), spontaneous meningitis (OR 4.2, 95% CI 1.9-9.1, P < 0.001), McCabe-Jackson score rapidly or ultimately fatal (OR 2.8, 95% CI 1.4-5.4, P = 0.002), MRSA infection (OR 2.6, 95% CI 1.3-5.3, P = 0.006), and coma (OR 2.6, 95% CI 1.1-6.1, P < 0.029). In postoperative cases, mortality was related to retention of cerebrospinal devices (OR 7.9, 95% CI 3.1-20.3, P < 0.001).

CONCLUSIONS

Clinical and epidemiological differences between MRSA and MSSA meningitis may be explained by the different pathogenesis of postoperative and spontaneous infection. In addition to the severity of meningitis and underlying diseases, MRSA infection was associated with increased mortality. Combined antimicrobial therapy was not associated with increased survival.

Early prosthetic joint infection: outcomes with debridement and implant retention followed by antibiotic therapy

Recent expert reviews recommend a conservative surgical strategy - debridement and irrigation, antibiotics and implant retention (DAIR) - for most early post-surgical prosthetic joint infections (PJI). However, differences exist in published series regarding success rates with DAIR, and the size of most series is small. In this prospective multicenter cohort study of early PJI managed by DAIR, factors associated with failure of the DAIR were analyzed. Out of 139 early PJI, 117 cases managed with DAIR were studied For 67 patients (57.3%), infection was cured and the implant was salvaged with definite antimicrobial therapy. In 35 (29.9%) DAIR failed and removal of the prosthesis was necessary during follow-up. Finally, 15 patients (12.8%) needed chronic suppressive antimicrobial therapy due to suspected or confirmed persistent infection. Infections due to methicillin-resistant S. aureus (72.7% failed; p 0.05) and those treated at one of the hospitals (80.0% failed; p <0.05) had worse outcomes, but only this last variable was associated with treatment failure following multivariate analysis. Seventy-four per cent of patients who were successfully treated by DAIR and only 32.7% of the failures were able to walk without help or with one stick at the last follow-up visit (p <0.05). In conclusion, a substantial proportion of patients with an early PJI may be successfully treated with DAIR and definite antimicrobial therapy. In more than half of these, the infection can be cured. Since identification of factors associated with failure of DAIR is not simple, we recommend offering DAIR to most patients with early PJI.

[Autochthonous amebic liver abscess in Spain: an emerging disease? Case report and description of a PCR-based diagnostic test]

INTRODUCTION

In Spain an increase in cases of amebiasis has been detected in patients with no history of traveling to, or immigration from, endemic areas.

MATERIAL AND METHODS

This study describes two new cases of amebic hepatic abscess due to native protozoa and reviews 21 more cases of amebic hepatic abscess reported in Spanish patients who had never left the Iberian Peninsula. In addition, a new PCR-based technique for diagnosing Entamoeba histolytica is described.

RESULTS

Twenty cases (87%) occurred in men. The age range of the affected patients was 26 to 77 years. Two of the 3 women with extraintestinal amebiasis were HIV-positive. There was no history of exposure to the parasite in 17 cases. In the remaining 6 cases, direct contact with patients affected with amebiasis or with individuals or foods from endemic areas was recorded.

CONCLUSION

Entamoeba histolytica infection is becoming an emerging disease in our country. Amebiasis should be included in the differential diagnosis of consistent clinical entities even when there is no background of traveling or immigration. New molecular diagnostic tools can help to characterize this infection and should be considered reference techniques in combination with serological methods.

Reassessment of Clostridium difficile susceptibility to metronidazole and vancomycin

Clostridium difficile is the most frequently identified enteric pathogen in patients with nosocomially acquired, antibiotic-associated diarrhea. The drugs most commonly used to treat diseases associated with C. difficile are metronidazole and vancomycin. Most clinical laboratories assume that all C. difficile isolates are susceptible to metronidazole and vancomycin. We report on the antimicrobial susceptibilities of 415 C. difficile isolates to metronidazole and vancomycin over an 8-year period (1993 to 2000). The overall rate of resistance to metronidazole at the critical breakpoint (16 microg/ml) was 6.3%. Although full resistance to vancomycin was not observed, the overall rate of intermediate resistance was 3.1%. One isolate had a combination of resistance to metronidazole and intermediate resistance to vancomycin. Rates of resistance to metronidazole and vancomycin were higher among isolates from human immunodeficiency virus-infected patients. Molecular typing methods proved the absence of clonality among the isolates with decreased susceptibilities to the antimicrobials tested.

Extra-intestinal infections caused by Clostridium difficile

The objective of this paper was to investigate the incidence of extra-intestinal infections caused by Clostridium difficile. During a 10-year period, the microbiology laboratory of our institution isolated 2034 isolates of C. difficile. Of the 2034 isolates, 21 (1.08%) were obtained from extra-intestinal sources. This represents an incidence of extra-intestinal isolation of four cases per 100 000 admissions. We were able to review the records of 17 patients for our study. The isolates in 12 patients were obtained from structures or fluids anatomically close to the colon and included the following infections: peritonitis in five cases (three primary and two secondary), intra-abdominal abscesses in three patients and abdominal wound infections in four cases. The infections in the other five patients were not in the anatomic vicinity of the colon. They included one case with a brain abscess, two episodes of bacteremia and two cases of foot infections (one chronic osteomyelitis). In all but one case, C. difficile isolation was obtained as part of a polymicrobial flora. The isolates were frequently non-toxigenic and the extra-intestinal infections occurred without concomitant diarrhea or prior anti-microbial therapy. Out of the 17 patients, eight died and nine survived. Death could not be directly attributed to C. difficile in any of the cases. The isolation of C. difficile outside the intestinal tract is very uncommon. Its clinical significance should be interpreted with caution.

Feculent meningitis: polymicrobial meningitis in colorectal surgery

Polymicrobial anaerobic meningitis is a rare event secondary to a contiguous infection in the head or neck. Anaerobic meningitis due to a meningo-intestinal fistula is a rare event with only two cases reported in the literature. We describe a new case of adult polymicrobial anaerobic meningitis after colorectal surgery and radiotherapy and review the previous two cases.

Differences in curable STDs between HIV and non-HIV populations in Spain

The pandemic impact of HIV has changed the clinical spectrum of STDs all over the world. The incidence and frequency of STDs in the different global geographic areas demonstrate the diagnostic and treatment capabilities of various local and national health systems and is simultaneously informing about the sexual behaviours of the population. The purpose of this study was to determine the frequency of curable STDs (herpes, chlamydia, gonorrhoea, syphilis, trichomoniasis) in a hospital-based STD clinic in Madrid, Spain during a 4-year period. Patients were referred mainly from the emergency department, gynecological wards, and family planning (61%) as well as from the HIV-hospital unit (31 beds) and outpatient department (39%). The total number of patients seen was 952 (243 men, 709 women) with an annual average of 238 patients per year. Of these, 139 (14.6%) were HIV-patients and 813 (85.4%) non-HIV patients. In non-HIV patients, STDs were identified in 493 cases (54.2%). In HIV-patients, STDs were diagnosed in 108 cases (77.7%; p < or = 0.001). Two or more STDs were more prevalent in HIV than non-HIV patients. The frequency of STDs in both HIV and non-HIV patients were vulvovaginal candidiasis, 47.8%:57.2%; syphilis, 11.7%:1.4% (p < or = 0.05); gonorrhea, 5.3%:3.9%; Gardnerella vaginosis, 6.3%:4.8%; genital chlamydia, 6.3%:9.06%; trichomoniasis, 17%:6.5% (p < or = 0.05); and genital herpes, 20.2%:5.3% (p < or = 0.05).

[Cerebral abscess as a complication of chronic otitis media]

A case is reported of chronic otitis media and cholesteatoma in an adult patient with behavioral disorders who developed a pyogenic brain abscess. Initially, clinical management focused on the otogenic disease in view of the patient's symptoms and medical history. Finally, less easily recognized discriminating signs and symptoms, and the results of imaging studies were emphasized. These data confirmed the clinical diagnosis of pyogenic brain abscess secondary to cholesteatoma. The case illustrates how one of the most severe infective complications related with cholesteatoma may appear and its a remainder to clinicians to take this possibility into consideration.

[Evaluation of blood cultures in anaerobiosis]

BACKGROUND

The rate of processed blood cultures from anaerobic bottles was checked and the number of isolates from anaerobic microorganisms and other non anaerobic ones from processed bottles was established. Next, we studied the relationship between bacteremia caused by anaerobic organisms and the clinical history.

METHODS

A total of 3.540 blood cultures have been checked for a period of 21 months; all of them were processed using Bactec NR 730 system. Those patients suffering bacteremia caused by anaerobic microorganisms had their medical histories revised. There is neither Gynecology nor Pediatrics Services at our Medical Center.

RESULTS

Eleven episodes of bacteremias caused by anaerobic microorganisms have been detected since we started our research 21 months ago. Three aerobic microorganisms grew only in the two processed bottles in anaerobiosis, being their respective aerobic cultures negative. In all cases of bacteremia caused by anaerobic bacteria, the clinical history was compatible with this infection.

CONCLUSIONS

We consider it is worth keeping the anaerobic bottles, because the number of anaerobic microorganisms isolates is considerable and clinically significant. A 2.76% incidence, where there is not gynecologist hospitalization, seems to be a high and relevant one. An alternative approach is to perform them only under certain clinical circumstances, although the process of collecting samples would make it a difficult task.

Immunorestorative effect of thymostimulin on surgery immunodepression: experimental model

The purpose of the present study is to ascertain the immunorestorative effect of two different drugs on immunodepression induced by small bowel surgical resection in an experimental model. The potential immunorestorative effect has been measured by the ability of the drug to avoid the delay of skin allograft rejection induced by surgery and the inhibition of CD4/CD8 index changes induced by surgery in spleen tissue. 120 Wistar-Furth rats (age 12-16 weeks) anesthetized with a single intramuscular dose of ketamine (25 mg), diazepine (4 mg) and atropine (0.1 mg) were allotted to two main groups. One group received a skin graft (SG) from Fisher 344 rats and was treated with placebo, Inmunoferón (AM-3 polypeptidic drug) or TP-1 (thymostimulin) before the experiment (groups I, II, III) or treated with placebo, Inmunoferón or TP-1 before the experiment and underwent enterectomy and anastomosis (groups IV, V, VI). On the 2nd, 5th and 8th postoperative days, biopsies of the SG were taken and the signs of rejection were microscopically studied and evaluated by a pathologist as zero, incipient, moderate or massive. The other group was treated similarly, but the animals did not receive a SG and were splenectomized 5 days later. CD4 and CD8 lymphocyte subpopulations were identified by means of immunoperoxidase technique and monoclonal antibodies. Thymostimulin is able to stimulate the presence of SG rejection signs on the 2nd postoperative day in nonenterectomized animals and on the 8th postoperative day in nonenterectomized animals and on the 8th postoperative day in enterectomized rats and is able to avoid the decrease of the CD4/CD8 index in spleen tissue after surgical immunodepression.(ABSTRACT TRUNCATED AT 250 WORDS)