Low antibodies titer and serological cross-reaction between <Emphasis Type="Italic">Coxiella burnetii</Emphasis> and <Emphasis Type="Italic">Legionella pneumophila</Emphasis> challenge the diagnosis of mediastinitis,an emerging Q fever clinical entity

Background

Coxiella burnetii is an intracellular and fastidious bacterium responsible of acute and persistent Q fever infection. Endocarditis and vascular infections are the most common serious complications of acute Q fever.

Case report

We report the case of a 63-year-old man that presented a mediastinitis associated with a prosthetic vascular infection. Serological cross-reaction was observed between Coxiella burnetii, the agent of Q fever, and Legionella pneumophila with higher antibodies titer for L. pneumophila (IgG = 1:512) than for C. burnetii (phase I IgG = 1:400). We performed western blot with cross-adsorption that supports the diagnosis of C. burnetii infection. Two weeks later, a positive qPCR and culture for C. burnetii on swab taken from the mediastinal cutaneous fistula confirmed the definitive microbiological diagnosis of Q fever mediastinitis.

Conclusion

Cross-reactivity between C. burnetii and Legionella spp. has long been known and should be considered in patients with persistent infections. It is important to establish the definite diagnosis because the antibiotic treatment regimens and duration are significantly different. To the best of our knowledge, we reported here the first case of mediastinitis associated to C. burnetii and we diagnosed this persistent infection despite low anti-C. burnetii phase I IgG levels.

     

Gastric adenocarcinoma in a patient re-infected with <Emphasis Type="Italic">H. pylori</Emphasis> after regression of MALT lymphoma with successful anti-<Emphasis Type="Italic">H. pylori</Emphasis>therapy and gastric resection: a case report

Background

Helicobacter pylori (H. pylori) has been etiologically linked with primary gastric lymphoma (PGL) and gastric carcinoma (GC). There are a few reports of occurrence of both diseases in the same patient with H. pylori infection.

Case presentation

We report a patient with PGL in whom the tumor regressed after surgical resection combined with eradication of H. pylori infection. However, he developed GC on follow up; this was temporally associated with recrudescence / re-infection of H. pylori. This is perhaps first report of such occurrence.

Conclusions

Possible cause and effect relationship between H. pylori infection and both PGL and GC is discussed. This case also documents a unique problem in management of PGL in tropical countries where re-infection with H. pylori is supposed to be high.

     

First case of <Emphasis Type="Italic">E. meningoseptica</Emphasis> in Italy in a patient with necrotic hemorrhagic pancreatitis

Introduction

Elizabethkingia meningoseptica can frequently colonizes the respiratory tract, but its pathogenetic role and its clinical significance are frequently questioned. However, recent data reported E. meningoseptica outbreaks in particular settings, as hospitalized patients.

Case Report

We report here the first case of Elizabethkingia meningoseptica infection in Italy in a patient with necrotic-hemorrhagic pancreatitis. E. meningoseptica was isolated from respiratory tract and treated with combination antibiotic therapy.

Conclusion

We discuss here the role of isolation of E. meningoseptica in hospitalized patients as a sign of patient’s frailty.

     

Essentials in the management of <Emphasis Type="Italic">S. aureus</Emphasis> bloodstream infection

Aims

Staphylococcus aureus bloodstream infection is one of the most common serious bacterial infections worldwide. It represents a heterogenous clinical entity with a high risk of metastatic complications and a high in-hospital mortality ranging between 20 and 30%. The outcome can be improved by optimised diagnostic and therapeutic management. Thus, our minireview should provide important and often missed pieces of information in the management of S. aureus bloodstream infection.

Methods

We describe the essentials in the management of S. aureus bloodstream infection.

Results

Five essentials were identified: 1) S. aureus bacteremia should always be considered clinically significant. 2) Length of bacteremia and fever is relevant for diagnostic workup, duration of therapy and prognosis. 3) Prompt identification and eradication of portal of entry and infective/metastatic foci are essential. 4) Infective endocarditis should be excluded. 5) Intravenous treatment for at least two weeks up to 4–6 weeks with antistaphylococcal penicillins for MSSA and vancomycin or daptomycin for MRSA bloodstream infection is indicated.

Conclusion

Further efforts should be undertaken to increase the adherence to the essentials in the management of S. aureus bloodstream infection.

     

Disseminated nocardiosis caused by <Emphasis Type="Italic">Nocardia elegans</Emphasis>: a case report and review of the literature

Background

Disseminated nocardiosis is a rare disease mostly occurring in immunocompromised patients.

Methods

We report a case of disseminated nocardiosis in a diabetic patient with both pulmonary and cutaneous involvement. Nocardia elegans was isolated and identified using the 16s ribosomal RNA gene sequence data.

Results

Clinical improvement was observed within 3 months after initiation of antimicrobial treatment with oral doxycycline, trimethoprim-sulfamethoxazole and intravenous penicillin, but the patient died 5 months later after arbitrary discontinuation of the treatment.

Conclusions

This is the first case report of disseminated nocardiosis caused by Nocardia elegans in China.

     

Ceftolozane/tazobactam for the treatment of MDR <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> left ventricular assist device infection as a bridge to heart transplant

Background

Ceftolozane/tazobactam (C/T) is a novel antibiotic with enhanced microbiological activity against multidrug-resistant (MDR) gram-negative bacteria, including MDR Pseudomonas aeruginosa.

Case report

Five months after left ventricular assist device (LVAD) implantation, a 49-year old man developed fever and blood culture was positive for MDR P. aeruginosa, susceptible only to aminoglycosides, ciprofloxacin and colistin. A diagnosis of LVAD-related infection was made based on persistent bacteremia associated with moderate 18 F-fluorodeoxyglucose positron emission tomography/CT uptake in the left ventricular apex. Disk diffusion testing for C/T was performed (MIC 2 μg/mL) and intravenous antibiotic therapy with C/T and amikacin was started, with clinical and microbiological response. Initial conservative management with 6 weeks of systemic antibiotic therapy was attempted, but the patient relapsed one month after antibiotic discontinuation. Priority for transplantation was given and after 4 weeks of antibiotic therapy (C/T + amikacin), LVAD removal and heart transplant were performed, with no infection relapse.

Conclusions

We reported the first off-label use of C/T in the management of MDR P. aeruginosa LVAD infection as a bridge to heart transplant. C/T has shown potent anti-pseudomonal activity and good safety profile making this drug as a good candidate for suppressive strategy in intravascular device-associated bloodstream infections caused by MDR P. aeruginosa.

     

Genome characterization of bile-isolated <Emphasis Type="Italic">Shewanella algae</Emphasis> ACCC

Background

Shewanella algae has been recognized as an emerging human pathogen. However, not much is known about the mechanism of its pathogenesis and its adaptation to a special niche such as the hepatobiliary tract.

Results

In this study, we isolated the S. algae ACCC strain from human bile and performed whole genome sequencing. S. algae ACCC consists of a circular 4,743,354-bp chromosome with a GC content of 53.08%, within 4080 protein coding sequences. The genome of strain ACCC contains a number of candidate genes which have been reported to be associated with bile adaption, including htpB, exbBD, wecA, galU, adeFGH and phoPQ regulon.

Conclusions

Our results highlight the association of S. algae with a rare disease profile. Further studies are needed to shed light on the evolution of pathogenesis and the niche adaptation of S. algae.

     

Were all carbapenemases created equal? Treatment of NDM-producing extensively drug-resistant <Emphasis Type="Italic">Enterobacteriaceae</Emphasis>: a case report and literature review

Purpose

There is currently a paucity of published literature focused on the treatment of infections caused by NDM-producing organisms.

Methods

We describe a case of a bacteraemia caused by an extensively drug-resistant (XDR) New Delhi metallo-β-lactamase (NDM)-producing Serratia marcescens and review the treatment options for XDR NDM-producing Enterobacteriaceae.

Results

Infections caused by New Delhi beta-lactamase (NDM)-producing Enterobacteriaceae are becoming increasingly prevalent worldwide. The presence of the enzyme results in multidrug-resistant and extensively drug-resistant phenotypes which often pose a treatment challenge. Despite this challenge, case reports and series have demonstrated good clinical outcomes with numerous treatment options in comparison to infections due to KPC-producing Enterobacteriaceae.

Conclusions

Further good-quality research focused on the treatment of NDM-producing Enterobacteriaceae is warranted.

     

Fatal <Emphasis Type="Italic">Neisseria macacae</Emphasis> infective endocarditis: first report

Introduction

Neisseria macacae is a Gram-negative diplococcus, found in the oropharynx of healthy Rhesus Monkeys. Infections caused by N. macacae in humans are extremely rare.

Case presentation

We present here the first case of N. macacae infective endocarditis in a 65-year-old man with a native aortic valve infection complicated by a peri-aortic abscess. N. macacae was isolated from blood culture and was found on the cardiac valve using 16S rDNA detection. Despite an appropriate antibiotic therapy, and aortic homograft replacement, and mitral repair, the patient died 4 days after surgery from a massive hemorrhagic stroke.

     

A human stool-derived <Emphasis Type="Italic">Bilophila wadsworthia</Emphasis> strain caused systemic inflammation in specific-pathogen-free mice

Background

Bilophila wadsworthia is a major member of sulfidogenic bacteria in human gut, it was originally recovered from different clinical specimens of intra-abdominal infections and recently was reported potentially linked to different chronic metabolic disorders. However, there is still insufficient understanding on its detailed function and mechanism to date.

Methods

A B. wadsworthia strain was isolated from fresh feces of a latent autoimmune diabetes in adults patient and we investigated its pathogenicity by oral administration to specific-pathogen-free mice. Tissue samples and serum were collected after sacrifice. Stool samples were collected at different time points to profile the gut microbiota.

Results

Bilophila wadsworthia infection resulted in the reduction of body weight and fat mass, apparent hepatosplenomegaly and elevated serum inflammatory factors, including serum amyloid A and interleukin-6, while without significant change of the overall gut microbiota structure.

Conclusions

These results demonstrated that higher amount of B. wadsworthia caused systemic inflammatory response in SPF mice, which adds new evidence to the pathogenicity of this bacterium and implied its potential role to the chronic inflammation related metabolic diseases like diabetes.

     

Essentials in <Emphasis Type="Italic">Candida</Emphasis> bloodstream infection

Aims

Due to the increase of severely immunocompromised patients, of invasive procedures including central intravascular catheters, and of the use of broad-spectrum antibiotics, the incidence of Candida bloodstream infections has risen intensely in the last decades. Candida bloodstream infection is a serious disease with high mortality. Optimized diagnostic and therapeutic management can improve outcome. Thus, the aim of our mini-review is to highlight important and often missed opportunities in the management of Candida bloodstream infection.

Methods

We searched the published literature and describe the essentials in the management of Candida bloodstream infection.

Results

Four essentials were identified: (1) isolation of Candida spp. from a blood culture should always be considered relevant and requires treatment. Daily blood cultures should be drawn to determine cessation of candidemia. (2) Central venous catheter (CVC) and/or other indwelling devices should be removed. (3) Echinocandins are the first choice. Antifungal treatment should be continued for at least 14 days after cessation of fungemia. Susceptibility testing should be performed to identify resistance and to facilitate transition to oral treatment. (4) In persistent candidemia, echocardiography is an important investigation; ophthalmoscopy should be considered.

Conclusion

Further efforts should be undertaken to increase the adherence to the essentials in the management of Candia bloodstream infection.

     

Association of <Emphasis Type="Italic">Helicobacter pylori</Emphasis> with hepatobiliary stone disease,a prospective case control study

Background

Hepatobiliary stone disease is one of the most common surgical conditions worldwide. There are multiple causative agents responsible for the formation of hepatobiliary stones, and bacterial infection is one of them. The presence of Helicobacter DNA species has been investigated in the biliary epithelium of patients with biliary diseases. However, conflicting results have been observed that may have been due to the small number of subjects studied, difficulty in obtaining a healthy control group, absence of controlling for confounding factors, or ethical and regional differences among populations.

Methods

We investigated the presence of Helicobacter pylori species by PCR of 26-kDa surface antigen specific to H. pylori in bile samples from 50 cases with hepatobiliary stones and 25 controls without hepatobiliary stones. The control group comprised of 20 patients of hydatid cyst disease of liver and 5 patients of right colonic growth.

Result

H. pylori was present in 20 bile samples among cases and was absent in 30 bile samples among cases. Among controls, H. pylori could not be detected. A significant association of the presence of H. pylori with hepatobiliary stone disease was seen (p < 0.001).

Conclusion

There is an association between bile infection with H. pylori and hepatobiliary stone disease.

     

Complete genome sequence of the <Emphasis Type="Italic">Vibrio vulnificus</Emphasis> strain VV2014DJH,a human-pathogenic bacterium isolated from a death case in China

Background

Vibrio vulnificus, an opportunistic pathogen, is the causative agent of life-threatening septicemia and severe wound infections. However, the pathogenicity and virulence factors of V. vulnificus are not fully understood. Here we report the complete genome sequence of V. vulnificus VV2014DJH, which was isolated from a death case.

Results

The genome of the V. vulnificus VV2014DJH contains two circular chromosomes with a mean G+C content of 46.8%, but does not consists of any plasmids. The chromosome I and chromosome II consist of 3,303,590 and 1,770,972 bp, respectively. In addition, the genome consists of 4617 protein coding genes, 172 RNA genes and type I, II and III secretion systems were predicted.

Conclusions

In this study, the genomic information of the V. vulnificus VV2014DJH has been described. The information would contribute to the increasing scope and depth of Vibrio genome database, and provide insights into the pathogenicity and virulence factors of V. vulnificus.

     

Invasive <Emphasis Type="Italic">Candida auris</Emphasis> infections in Kuwait hospitals: epidemiology,antifungal treatment and outcome

Purpose

Candida auris is a recently recognized yeast pathogen, which has attracted worldwide attention due to its multidrug-resistant nature and associated high mortality rates. Its persistence in hospital environment and propensity of nosocomial transmission underscores the need of continuous monitoring to prevent outbreaks. Since the first case of C. auris candidemia in May, 2014, we have identified 17 additional invasive cases, which are described here.

Methods

Identity of 17 isolates originating from proven or possible cases of invasive C. auris infection and identified as Candida haemulonii by Vitek 2 yeast identification system was confirmed by PCR-sequencing of rDNA. Information about risk factors, treatment and outcomes were retrospectively retrieved from case files. Antifungal susceptibility testing was performed by Etest.

Results

Thirteen cases of candidemia and 4 cases of other invasive infections were detected in 6 hospitals across Kuwait. Major risk factors included adult patients with cancer, diabetes, gastrointestinal/liver diseases and extended (>?25 days) hospital stay. All isolates were resistant to fluconazole. Additionally, 5 and 4 isolates were also resistant to voriconazole and amphotericin B, respectively. Despite antifungal treatment, 9 of 15 patients died. Most patients (n?=?12) were hospitalized in 2 hospitals that are in close proximity, whereas 5 other patients were from 3 hospitals that are situated?>?10 km apart.

Conclusions

Occurrence of successive cases of invasive C. auris infections with resulting mortality in nine patients suggests persistence of this multidrug-resistant yeast in major hospitals in Kuwait. Early detection by continuous surveillance and enforcement of infection control measures are recommended.

     

Fluoroquinolone Restriction as an Effective Antimicrobial Stewardship Intervention

Purpose of review

Fluoroquinolones are a commonly prescribed antibiotic class that has come under scrutiny in recent years due to mounting evidence of association between adverse drug events, C. difficile infection and isolation of antibiotic-resistant bacteria.

Recent findings

Inpatient antimicrobial stewardship (AMS) programs have a toolbox of potential interventions to curb inappropriate antibiotic use, prevent antibiotic-associated adverse drug events, and avoid unnecessary costs of care. Fluoroquinolone restriction policies in the acute care setting have demonstrated beneficial effects, including decreased rates of C. difficile infection and ESBL-producing Enterobacteriaceae. However, a simple blanket restriction policy may “squeeze the antibiotic balloon” and will likely be insufficient if not implemented in conjunction with other AMS interventions.

Summary

There is a growing body of evidence to support formulary restriction of fluoroquinolones in the acute care setting to decrease rates of C. difficile infection and development of ESBL-producing organisms. Data on how to best implement these restrictions or how to implement outside of acute care settings is limited.

     

<Emphasis Type="Italic">Helicobacter pylori</Emphasis> infection status had no influence on upper gastrointestinal symptoms: a cross-sectional analysis of 3,005 Japanese subjects without upper gastrointestinal lesions undergoing medical health checkups

Background

This study aimed to evaluate the influence of Helicobacter pylori infection and its eradication on the upper gastrointestinal symptoms of relatively healthy Japanese subjects.

Methods

A total of 3,005 subjects (male/female: 1,549/1,456) undergoing medical health checkups were enrolled in the present study, at five hospitals in Saga, Japan, from January to December 2013. They had no significant findings following upper gastrointestinal endoscopy. All subjects completed a questionnaire that addressed a frequency scale for symptoms of gastroesophageal reflux disease. The questionnaire comprised seven questions regarding reflux symptoms and seven regarding acid-related dyspepsia, which were answered with a score based on the frequency of symptoms. Helicobacter pylori infection was identified by a rapid urease test and/or H. pylori antibody titer, and an eradication history was confirmed by the subjects’ medical records.

Results

Helicobacter pylori infection was positive in 894 subjects out of 3,005 (29.8%). Eradication of Helicobacter pylori was successfully achieved in 440 subjects of 458 treated. Helicobacter pylori infection had no influence on the acid-related dyspepsia evaluated by the questionnaire, whereas the mean reflux score was relatively high in the Helicobacter pylori native negative subjects compared to Helicobacter pylori native positive. Eradication of Helicobacter pylori and time span after the eradication had no effect on the upper gastrointestinal symptoms evaluated by the questionnaire.

Conclusion

Helicobacter pylori infection and history of eradication did not affect acid-related dyspepsia symptoms in Japanese healthy subjects.

     

Evaluation and management of <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> bacteriuria: an updated review

Background and aims

There is little guidance regarding the evaluation and management of patients with Staphylococcus aureus bacteriuria (SABU). Here, we aimed to provide an up-to-date review of the literature.

Methods

We searched PubMed, Scopus, and clinical trial registries for articles evaluating the epidemiology of SABU, risk factors of SABU, the association of SABU with urinary tract infection, bacteremia and invasive S. aureus infections, and the management of patients with SABU.

Results

S. aureus is an uncommon isolate in urine cultures. It is more common among certain patients, e.g., patients with indwelling urinary tract devices or prior urinary tract instrumentation. SABU may represent asymptomatic bacteriuria, primary urinary tract infection, or hematogenous seeding of the urinary tract associated with other foci of infection. SABU may also serve as the focus for subsequent bacteremia and invasive infections. We did not find any clinical trials regarding the management of patients with SABU.

Conclusions

Based on our review, we suggest an algorithmic approach for the evaluation and management of patients with SABU. However, evidence from clinical trials is lacking and there are severalgaps in the current literature. These are discussed in this review.

     

<Emphasis Type="Italic">Candida parapsilosis</Emphasis> Vaginal Infection—a New Site of Azole Drug Resistance

Purpose of Review

Evaluation of pathogenicity of an uncommon vaginal Candida species, Candida parapsilosis with particular references to susceptibility to conventional antifungal agents.

Recent Findings

C. parapsilosis vaginal isolates usually present in asymptomatic women as commensals but may induce vulvovaginal symptoms indistinguishable from C. albicans requiring antifungal therapy; however, recent experience reveals clinically relevant resistance to the azole class of antimycotics.

Conclusion

Clinicians are required to determine a causal relationship between vaginal isolates of C. parapsilosis before prescribing antifungal agents, recognizing the possibility of fluconazole resistance to explain refractory symptomatology.

     

Oncogenic miR-23a in Pancreatic Ductal Adenocarcinogenesis Via Inhibiting <Emphasis Type="Italic">APAF1</Emphasis>

Background

miR-23a, which participates in invasion of pancreatic ductal adenocarcinoma cells into the mesothelial barrier, is a critical regulator in many cancers. It, however, is still unknown whether miR-23a regulates pancreatic cell proliferation and apoptosis or not.

Aims

We sought to investigate the role of miR-23a in regulation of pancreatic cell proliferation and apoptosis.

Methods

miRNA, mRNA, and protein expressions were determined by qRT-PCR and Western blot, respectively. Dual-luciferase reporter assay was used in detection for binding ability of miR-23a to APAF1. Ectopic miR-23a and APAF 1 were introduced to pancreatic cells, and their roles in proliferation and apoptosis were detected by MTT, colony formation, and apoptosis assays, respectively.

Results

Up-regulation of miR-23a and down-regulation of APAF 1 were found in pancreatic ductal cancer, respectively. miR-23a significantly inhibited the luciferase activity by targeting APAF 1 3′UTR. Ectopic miR-23a significantly suppressed the APAF 1 gene expression in pancreatic cancer cells. Similar to siAPAF1, miR-23a significantly promoted pancreatic cancer cell proliferation and repressed apoptosis. Furthermore, miR-23a inhibitor and exogenous APAF 1 could recover the effects.

Conclusions

It is suggested that miR-23a, acting as an oncogenic regulator by directly targeting APAF 1 in pancreatic cancer, is a useful potential biomarker in diagnosis and treatment of pancreatic cancer.