The incidence of ventriculostomy-related infections as diagnosed by 16S rRNA polymerase chain reaction: A prospective observational study.

BACKGROUND: Ventriculostomy-related infections (VRIs) are reported in about 10 % of patients with external ventricular drains (EVDs). VRIs are difficult to diagnose due to clinical and laboratory abnormalities caused by the primary neurological injury which led to insertion of the EVD. Polymerase chain reaction (PCR) of the cerebrospinal fluid (CSF) may enable more accurate diagnosis of VRI. We performed a prospective cohort study to measure the incidence of VRI as diagnosed by 16S rRNA PCR. METHODS: Patients admitted to intensive care with a primary diagnosis of subarachnoid haemorrhage (SAH), traumatic brain injury (TBI), or intracerebral haemorrhage (ICH), who required an EVD, were assessed for inclusion in this study. Data were extracted from the electronic medical record, bedside charts, or from a prospectively collected database, the Neuroscience Outcomes in Intensive CarE database (NOICE). 16S rRNA PCR was performed on routinely collected CSF as per laboratory protocol. VRI was also diagnosed based on pre-existing definitions. RESULTS: 237 CSF samples from 39 patients were enrolled in the study. The mean patient age was 55.7 years, and 56.4 % were female. The most common primary neurological diagnosis was SAH (61.5 %). The incidence of a positive PCR was 2.6 % of patients (1 in 39) and 0.8 % of CSF samples (2 in 237). The incidence of VRI according to pre-published diagnostic criteria was 2.6 % - 41 % of patients and 0.4 % - 17.6 % of CSF samples. 28.2 % of patients were treated for VRI. Pre-published definitions which relied on CSF culture results had higher specificity and lower false positive rates for predicting a PCR result when compared to definitions incorporating non-microbiological markers of VRI. In CSF samples with a negative 16S rRNA PCR, there was a high proportion of non-microbiological markers of infection, and a high incidence of fever on the day the CSF sample was taken. CONCLUSIONS: The incidence of VRI as defined as a positive PCR was lower than the incidence of VRI according to several published definitions, and lower than the incidence of VRI as defined as treatment by the clinical team. Non-microbiological markers of VRI may be less reliable than a positive CSF culture in diagnosing VRI.

The association between ventriculostomy - Related infection and clinical outcomes: A systematic review and meta-analysis.

BACKGROUND: Ventriculostomy - related infection (VRI) is a common complication of patients who require placement of an external ventricular drain (EVD). The clinical outcomes of people who are diagnosed with VRI is poorly characterised. We performed a systematic review and meta-analysis to assess the association between VRI, and clinical outcomes and resource use, in patients treated with an EVD. METHODS: We searched MEDLINE, EMBASE, CINAHL and the Cochrane Central Register of clinical trials to identify clinical trial and cohort studies that reported outcomes including mortality, functional outcome, duration of EVD insertion, and intensive care and hospital length of stay. Inclusion criteria and data extraction were conducted in duplicate. Where sufficient data were available, data synthesis was conducted using a random effects model to provide a pooled estimate of the association between VRI and clinical outcomes and resource use. We also pooled data to provide an estimate of the incidence of VRI in this population. RESULTS: Nineteen studies including 38,247 patients were included in the meta-analysis. There were twelve different definitions of VRI in the included studies. The pooled estimate of the incidence of VRI was 11 % (95 % confidence interval (CI), 9 % to 14 %). A diagnosis of VRI was not associated with an increase in the estimated odds ratio (OR) for mortality (OR 1.07, 95 % CI 0.59 to 1.92, p = 0.83 I2 = 83.5 %), nor was a diagnosis of VRI associated with changes in neurological outcome (OR 1.42, 95 % CI 0.36 to 5.56, p = 0.89, I2 = 0.3 %). Those diagnosed with VRI had longer intensive care unit length of stay (estimated pooled mean difference 8.4 days 95 % CI 3.4 to 13.4 days, p = 0.0009, I2 = 78.7 %) an increase in hospital length of stay (estimated mean difference 16.4 days. 95 % CI 11.6 to 21.2 days, p < 0.0005, I2 = 76.6 %), a prolonged duration of EVD placement (mean difference 5.24 days, 95 % CI 3.05 to 7.43, I2 = 78.2 %, p < 0.01), and an increased requirement for an internal ventricular shunt (OR 1.80, 95 % CI 1.32 to 2.46, I2 = 8.92 %, p < 0.01). CONCLUSIONS: Ventriculostomy related infection is not associated with increased mortality or an increased risk of poor neurological outcome, but is associated with prolonged duration of EVD placement, prolonged duration of ICU and hospital admission, and an increased rate of internal ventricular shunt placement.

Early intravenous immunoglobulin therapy for group A ß-haemolytic streptococcal meningitis with toxic shock syndrome.

A woman in her forties was transferred to a Sydney (Australia)-based tertiary hospital, following presentation to a regional hospital with group A Streptococcus (GAS) otomastoiditis; complicated by meningitis, venous sinus thrombosis, haemorrhagic cerebral infarction and subdural empyema. She rapidly deteriorated with profound cardiovascular collapse. Despite initiation of high dose vasoactive therapy, she remained shocked and developed multiorgan dysfunction syndrome. Early intravenous immunoglobulin therapy (140 g in two doses) was initiated as an adjunct to antimicrobial, surgical and supportive care for refractory streptococcal toxic shock syndrome. Over the course of a twelve-day intensive care unit stay she made good progress with de-escalation of her vasoactive supportive care and reversal of her organ injuries. She was subsequently discharged to ward-based care. At her three-month follow-up appointment she had significantly reduced neurological deficit. Five months following her presentation to hospital she had returned to full-time work.

Topical antibiotics and intravitreal injections.

There is increasing evidence that topical antibiotics, given before and/or after intravitreal injections, are ineffective in preventing endophthalmitis and are possibly harmful. In addition to the lack of efficacy and increased development of resistant organisms, the use of topical antibiotics adds significantly to the cost of delivering intravitreal therapy. Despite this, in many countries, it is still common practice to use pre- and/or postinjection topical antibiotics. This review outlines the general principles of effective antibiotic prophylaxis, and the evidence regarding topical antibiotic use as a prophylactic measure for endophthalmitis following intravitreal injections. A key distinguishing feature of intravitreal injections from most other invasive procedures is the fact that they are often repeated on multiple occasions to the same eye. Given the lack of evidence to support topical antibiotics as an effective method of prophylaxis for postinjection endophthalmitis, it appears that more widespread education of ophthalmologists is required to avoid continued inappropriate use. Revision of drug labels in some jurisdictions, and amendment of local/professional society guidelines, may be required to assist in achieving this goal. Emphasis should be placed on antisepsis and aseptic technique, which are the major proven methods of endophthalmitis prevention, rather than antibiotics.

Phenotypical and genotypical characteristics of invasive group B Streptococcus isolates in Western Sydney 2000-2005.

AIMS: To analyse antimicrobial susceptibility and serotypes of group B streptococcus (GBS) bloodstream isolates from different patient groups. METHODS: Susceptibility to penicillin, erythromycin and clindamycin was measured for 99 bloodstream GBS isolates collected between October 2000 and July 2005. Multiplex PCR-based reverse line blot (mPCR/RLB) assays were used to identify macrolide resistance genes and capsular serotype for each isolate. Clinical correlation was obtained from chart review. RESULTS: Adult bacteraemia accounted for 84 of 99 (85%) isolates, and were usually associated with underlying diseases such as diabetes, malignancy and renal failure. Overall mortality was 10%. Known macrolide resistance genes [ermB (2), ermA/TR (3) and mefA/E (2)] were detected in seven of eight erythromycin resistance isolates. Four of these isolates expressed MLSB phenotype, two with constitutive (ermB) and two with inducible (ermA/TR) clindamycin resistance. Of four M phenotype isolates, two had mefA/E, one had ermA/TR and one had no detectable macrolide resistance genes. Serotype III was significantly more common in neonatal isolates; serotype V was more common among adult isolates and was associated with increased mortality. CONCLUSIONS: mPCR/RLB is a rapid molecular method to identify GBS serotype and macrolide resistance genes. This is the first major study correlating these characteristics with demographic data for invasive isolates.

Necrotizing infection due to Bacillus cereus mimicking gas gangrene following penetrating trauma.

An 8-year-old boy presented with fulminant necrotizing infection resembling gas gangrene following penetrating trauma from a tree branch. Bacillus cereus was isolated from tissue specimens, showing that unexpected pathogens can be isolated. It is essential to submit specimens for culture, as this organism is typically resistant to beta-lactam antibiotics and metronidazole, the empiric choice for gas gangrene.

Prosthesis related sepsis following laparoscopic adjustable gastric banding.

BACKGROUND: Laparoscopic adjustable gastric banding (LAGB) is well-recognized as a superior method to achieving durable weight loss in the medium term when compared with non-surgical methods of weight loss. In this paper, we described the clinical presentation and outcomes of patients presenting with band or band-adjustment reservoir sepsis from our series from a single institution. METHODS: We conducted a retrospective review of prospectively collected clinical, anthropometric and biochemical data from patients who underwent LAGB placement over a five-year period at a metropolitan teaching hospital. Those patients requiring surgical intervention for prosthesis-related sepsis were included in the review. RESULTS: Of the 445 patients in this series, 10 (2.2%) developed prosthesis sepsis and required operative intervention. Three (0.7%) presented with reservoir sepsis requiring removal of the reservoir. One had band erosion identified and the entire prosthesis removed. In seven (1.5%) of the patients, infections occurred at the gastric band. Two patients presented with purulent peritonitis and underwent immediate band removal. The remainder presented with band abscesses and either had their band removed (three patients) or left in position and the sepsis treated with drainage and antibiotics (two patients). CONCLUSIONS: In our current series, a small proportion of LAGB patients developed prosthesis-related infection that typically required port or band removal and usually occurred early in the post-operative course. We have modified our prophylactic antibiotic regime and surgical technique as a result of this review. In selected cases of band infection, bands were salvaged with subsequent acceptable weight loss, suggesting that LAGB salvage in the presence of sepsis may be achievable in some patients.

Simultaneous detection of nine antibiotic resistance-related genes in Streptococcus agalactiae using multiplex PCR and reverse line blot hybridization assay.

Streptococcus agalactiae (group B streptococcus [GBS]) is the leading cause of neonatal and maternal sepsis. Penicillin is recommended for intrapartum prophylaxis, but erythromycin or clindamycin is used for penicillin-allergic carriers. Antibiotic resistance (AR) has increased recently and needs to be monitored. We have developed a multiplex PCR-based reverse line blot (mPCR/RLB) hybridization assay to detect, simultaneously, seven genes encoding AR--erm(A/TR), erm(B), mef(A/E), tet(M), tet(O), aphA-3, and aad-6--and two AR-related genes, int-Tn and mreA. We tested 512 GBS isolates from Asia and Australasia and compared mPCR/RLB with antibiotic susceptibility phenotype or single-gene PCR. Phenotypic resistance to tetracycline was identified in 450 (88%) isolates, of which 442 had tet(M) (93%) and/or tet(O) (6%). Of 67 (13%) erythromycin-resistant isolates, 18 were susceptible to clindamycin, i.e., had the M phenotype, encoded by mef(A/E); 39 had constitutive (cMLS(B)) and 10 inducible clindamycin resistance, and of these, 34 contained erm(B) and 12 erm(A/TR). Of four additional isolates with mef(A/E), three contained erm(B) with cMLS(B) and one was erythromycin susceptible. Of 61 (12%) clindamycin-resistant isolates, 20 were susceptible to erythromycin and two had intermediate resistance. Based on sequencing, 21 of 22 isolates with mef had mef(E), and 8 of 353 with int-Tn had an atypical sequence. Several AR genes, erm(B), tet(O), aphA-3, aad-6, and mef(A/E), were significantly more common among Asian than Australasian isolates, and there were significant differences in distribution of AR genes between GBS serotypes. Our mPCR/RLB assay is simple, rapid, and suitable for surveillance of antibiotic resistance in GBS.