SIRS Triggered by Acute Right Ventricular Function, Mimicked Septic Shock.

BACKGROUND: The systemic inflammatory response syndrome (SIRS) is a complex immune response which can be precipitated by non-infectious aetiologies such as trauma, burns or pancreatitis. Addressing the underlying cause is crucial because it can be associated with increased mortality. Although the current literature associates chronic heart failure with SIRS, acute right ventricular dysfunction has not previously been reported to trigger SIRS. This case report describes the presentation of acute right ventricular dysfunction that triggered SIRS and mimicked septic shock. CASE PRESENTATION: A 70-year-old male presented to the Intensive Care Unit (ICU) with elevated inflammatory markers and refractory hypotension after a robotic-assisted laparoscopic radical choledochectomy with pancreaticoduodenectomy. Septic shock was misdiagnosed, and he was later found to have a pulmonary embolus. Thrombectomy and antimicrobials had no significant efect on lowering the elevated inflammatory markers or improving the persistent hypotension. Through Point of Care Ultrasound (POCUS), right ventricular dysfunction was diagnosed. Treatment with intravenous milrinone improved blood pressure, normalised inflammatory markers and led to a prompt discharge from the ICU. CONCLUSION: Acute right ventricular dysfunction can trigger SIRS, which may mimic septic shock and delay appropriate treatment

Community-associated Methicillin-resistant Staphylococcus aureus, Singapore

10.3201/eid1102.040782Emerging Infectious Diseases112341-34

Atypical SARS and Escherichia coli Bacteremia

We describe a patient with severe acute respiratory syndrome (SARS) whose clinical symptoms were masked by Escherichia coli bacteremia. SARS developed in a cluster of healthcare workers who had contact with this patient. SARS was diagnosed when a chest infiltrate developed and when the patient’s brother was hospitalized with acute respiratory failure. We highlight problems in atypical cases and offer infection control suggestions

In-Vitro Activity of Polymyxin B, Rifampicin, Tigecycline Alone and in Combination against Carbapenem-Resistant Acinetobacter baumannii in Singapore

OBJECTIVE: Carbapenem-resistant Acinetobacter baumannii (CR-AB) is an emerging cause of nosocomial infections worldwide. Combination therapy may be the only viable option until new antibiotics become available. The objective of this study is to identify potential antimicrobial combinations against CR-AB isolated from our local hospitals. METHODS: AB isolates from all public hospitals in Singapore were systematically collected between 2006 and 2007. MICs were determined according to CLSI guidelines. All CR-AB isolates were genotyped using a PCR-based method. Clonal relationship was elucidated. Time-kill studies (TKS) were conducted with polymyxin B, rifampicin and tigecycline alone and in combination using clinically relevant (achievable) unbound concentrations. RESULTS: 31 CR AB isolates were identified. They are multidrug-resistant, but are susceptible to polymyxin B. From clonal typing, 8 clonal groups were identified and 11 isolates exhibited clonal diversity. In single TKS, polymyxin B, rifampicin and tigecycline alone did not exhibit bactericidal activity at 24 hours. In combination TKS, polymyxin plus rifampicin, polymyxin B plus tigecycline and tigecycline plus rifampicin exhibited bactericidal killing in 13/31, 9/31 and 7/31 isolates respectively at 24 hours. Within a clonal group, there may be no consensus with the types of antibiotics combinations that could still kill effectively. CONCLUSION: Monotherapy with polymyxin B may not be adequate against polymyxin B susceptible AB isolates. These findings demonstrate that in-vitro synergy of antibiotic combinations in CR AB may be strain dependant. It may guide us in choosing a pre-emptive therapy for CR AB infections and warrants further investigations

Risk Factors, Molecular Epidemiology and Outcomes of Ertapenem-Resistant, Carbapenem-Susceptible Enterobacteriaceae: A Case-Case-Control Study

Background: Increasing prevalence of ertapenem-resistant, carbapenem-susceptible Enterobacteriaceae (ERE) in Singapore presents a major therapeutic problem. Our objective was to determine risk factors associated with the acquisition of ERE in hospitalized patients; to assess associated patient outcomes; and to describe the molecular characteristics of ERE. Methods: A retrospective case-case-control study was conducted in 2009 at a tertiary care hospital. Hospitalized patients with ERE and those with ertapenem-sensitive Enterobacteriaceae (ESE) were compared with a common control group consisting of patients with no prior gram-negative infections. Risk factors analyzed included demographics; co-morbidities; instrumentation and antibiotic exposures. Two parallel multivariate logistic regression models were performed to identify independent variables associated with ERE and ESE acquisition respectively. Clinical outcomes were compared between ERE and ESE patients. Results: Twenty-nine ERE cases, 29 ESE cases and 87 controls were analyzed. Multivariate logistic regression showed that previous hospitalization (Odds ratio [OR], 10.40; 95 % confidence interval [CI], 2.19–49.20) and duration of fluoroquinolones exposure (OR, 1.18 per day increase; 95 % CI, 1.05–1.34) were unique independent predictors for acquiring ERE. Duration of 4 th-generation cephalosporin exposure was found to predict for ESE acquisition (OR, 1.63 per day increase; 95 % CI, 1.05– 2.54). In-hospital mortality rates and clinical response rates were significantly different between ERE and ESE groups

MORAXELLA CATARRHALIS OUTER MEMBRANE PROTEINS AND THEIR INTERACTIONS WITH THE HUMAN HOST

Moraxella catarrhalis is an airway pathogen whose role in infection has been increasingly recognized in recent years. Most authorities in this field now agree that M. catarrhalis causes significant morbidity and is not just a harmless commensal. The universal prevalence of BRO ?-lactamases in this pathogen is a serious concern. In addition, M. catarrhalis may be further propelled into a more prominent position in the hierarchy of respiratory infectious agents due to the phenomenon of ?non-vaccine type replacement? as a result of the wider usage of vaccines against other pathogens in the same ecological niche, such as Haemophilus influenzae and Streptococcus pneumoniae. There is currently no available vaccine against M. catarrhalis. A detailed analysis of the interactions of this bacterium with the human host is necessary to identify ways to interfere with its colonization and infection. To this end, we have focused on the interactions via three outer membrane proteins, namely UspA1 (ubiquitous surface protein A1), UspA2 and MID (Moraxella catarrhalis IgD binding protein). We found that UspA1 and A2 could bind fibronectin and laminin, and characterized these interactions. We also detailed a novel interaction of UspA1 and A2 with the complement protein C3. The UspA1/A2-dependent C3 binding contributes to its serum resistant phenotype and is a way in which M. catarrhalis combat the innate immunity. Furthermore, we showed that this interaction could contribute to the survival of copathogens. An analysis of naturally acquired serological responses to these two proteins and those of MID showed that the functional domains identified here (fibronectin binding region in UspA1299-452 and UspA2165-318, C3 binding region in UspA2) and those identified in other studies (CEACAM binding region of UspA1, the MID764-913 adhesive domain) evoked significant immune responses. The better understanding of the interactions and the identification of important domains in these three proteins represent significant advances in the quest for a suitable vaccine against M. catarrhalis

Current progress of adhesins as vaccine candidates for Moraxella catarrhalis

Moraxello catorrhalis is an emerging pathogen and all isolates are now considered beta-lactamase producing. Potential further use of vaccines against Streptococcus pneumoniae and nontypeable Haemophilus influenzae means that M. catarrhalis might be thrust further into the limelight. However, a vaccine has not yet been designed. In this review, the progress of M. catarrhalis adhesins as vaccine candidates is discussed with a focus on various candidate antigens that spanned those discovered more than 10 years ago, for example, the ubiquitous surface proteins to newer antigens, such as the Moraxella IgD-binding hemagglutinin

Resistant cytomegalovirus infection in renal transplant recipients

Resistant cytomegalovirus infection is a significant problem in the transplant population including renal transplant recipients. A combination of factors including receipt of potent immunosuppression, high viral loads and suboptimal levels of anti-cytomegalovirus antivirals leads to emergence of resistant strains. Reports of associated poor graft survival and mortality demonstrate the potential pathogenic nature of such strains. Genotypic and phenotypic resistance testing are available for laboratory diagnosis of resistant cytomegalovirus infection and may help guide therapy. Various agents, including novel and newly minted antivirals and treatment approaches have been employed, with variable success. Thus, in spite of major advances in both diagnostics and therapeutics, management of resistant cytomegalovirus infection in renal transplant recipients remains a challenging prospect