Characterisation of colistin resistance in Gram-negative microbiota of pregnant women and neonates in Nigeria.

A mobile colistin resistance gene mcr was first reported in 2016 in China and has since been found with increasing prevalence across South-East Asia. Here we survey the presence of mcr genes in 4907 rectal swabs from mothers and neonates from three hospital sites across Nigeria; a country with limited availability or history of colistin use clinically. Forty mother and seven neonatal swabs carried mcr genes in a range of bacterial species: 46 Enterobacter spp. and single isolates of; Shigella, E. coli and Klebsiella quasipneumoniae. Ninety percent of the genes were mcr-10 (n = 45) we also found mcr-1 (n = 3) and mcr-9 (n = 1). While the prevalence during this collection (2015-2016) was low, the widespread diversity of mcr-gene type and range of bacterial species in this sentinel population sampling is concerning. It suggests that agricultural colistin use was likely encouraging sustainment of mcr-positive isolates in the community and implementation of medical colistin use will rapidly select and expand resistant isolates.

Antibiotic resistance genes in the gut microbiota of mothers and linked neonates with or without sepsis from low- and middle-income countries.

Early development of the microbiome has been shown to affect general health and physical development of the infant and, although some studies have been undertaken in high-income countries, there are few studies from low- and middle-income countries. As part of the BARNARDS study, we examined the rectal microbiota of 2,931 neonates (term used up to 60 d) with clinical signs of sepsis and of 15,217 mothers screening for blaCTX-M-15, blaNDM, blaKPC and blaOXA-48-like genes, which were detected in 56.1%, 18.5%, 0% and 4.1% of neonates' rectal swabs and 47.1%, 4.6%, 0% and 1.6% of mothers' rectal swabs, respectively. Carbapenemase-positive bacteria were identified by MALDI-TOF MS and showed a high diversity of bacterial species (57 distinct species/genera) which exhibited resistance to most of the antibiotics tested. Escherichia coli, Klebsiella pneumoniae and Enterobacter cloacae/E. cloacae complex, the most commonly found isolates, were subjected to whole-genome sequencing analysis and revealed close relationships between isolates from different samples, suggesting transmission of bacteria between neonates, and between neonates and mothers. Associations between the carriage of antimicrobial resistance genes (ARGs) and healthcare/environmental factors were identified, and the presence of ARGs was a predictor of neonatal sepsis and adverse birth outcomes.

Rapid detection and differentiation of mobile colistin resistance (mcr-1 to mcr-10) genes by real-time PCR and melt-curve analysis.

BACKGROUND: The emergence of multi-drug-resistant (MDR) micro-organisms prompted new interest in older antibiotics, such as colistin, that had been abandoned previously due to limited efficacy or high toxicity. Over the years, several chromosomal-encoded colistin resistance mechanisms have been described; more recently, 10 plasmid-mediated mobile colistin resistance (mcr) genes have been identified. Spread of these genes among MDR Gram-negative bacteria is a matter of serious concern; therefore, reliable and timely mcr detection is paramount. AIM: To design and validate a multiplex real-time polymerase chain reaction (PCR) assay for detection and differentiation of mcr genes. METHODS: All available mcr alleles were downloaded from the National Center for Biotechnology Information Reference Gene Catalogue, aligned with Clustal Omega and primers designed using Primer-BLAST. Real-time PCR monoplexes were optimized and validated using a panel of 120 characterized Gram-negative strains carrying a wide range of resistance genes, often in combination. Melt-curve analysis was used to confirm positive results. FINDINGS: In-silico analysis enabled the design of a 'screening' assay for detection of mcr-1/2/6, mcr-3, mcr-4, mcr-5, mcr-7, mcr-8 and mcr-9/10, paired with an internal control assay to discount inhibition. A 'supplementary' assay was subsequently designed to differentiate mcr-1, mcr-2, mcr-6, mcr-9 and mcr-10. Expected results were obtained for all strains (100% sensitivity and specificity). Melt-curve analysis showed consistent melting temperature results. Inhibition was not observed. CONCLUSIONS: The assay is rapid and easy to perform, enabling unequivocal mcr detection and differentiation even when more than one variant is present. Adoption by clinical and veterinary microbiology laboratories would aid the surveillance of mcr genes amongst Gram-negative bacteria.

Rapid detection of OXA-23-like, OXA-24-like, and OXA-58-like carbapenemases from Acinetobacter species by real-time PCR.

BACKGROUND: Carbapenemase-producing Acinetobacter species, especially A. baumannii, are frequently associated with treatment failures and hospital outbreaks; thus, rapid and reliable detection of specific resistance markers is paramount. The most common carbapenemases found in A. baumannii, namely OXA-23-like, OXA-24-like, and OXA-58-like, belong to the oxacillinase group (class D ß-lactamases) which is notoriously difficult to identify phenotypically due to the lack of specific inhibitors. AIM: To design and validate a multiplex real-time polymerase chain reaction (PCR) assay to detect and differentiate the above three oxacillinases. METHODS: All available variants of the above three oxacillinase subfamilies were downloaded (as of November 2019) from the Beta-Lactamase DataBase (http://bldb.eu/) aligned with Clustal Omega and oligonucleotides designed using Primer-BLAST. A multiplex real-time PCR assay that included an internal control to discount inhibition was optimized on the Rotor-Gene Q (Qiagen) using the Rotor-Gene Multiplex PCR Kit (Qiagen) and validated using a panel of 122 previously characterized strains carrying a wide range of ß-lactamases, often in combination. FINDINGS: The in-silico approach enabled the design of oligonucleotides in conserved regions of the OXA-24-like and OXA-58-like alignments. Among the 42 described OXA-23-like variants, a single nucleotide polymorphism (SNP) was present in one of the oligonucleotide binding sites of OXA-27, OXA-166, OXA-811, OXA-812, and OXA-816. The assay was 100% sensitive and highly specific. Inhibition was not observed. CONCLUSION: The assay is easy to perform with results available in about 70 min. It enables unequivocal detection and differentiation of OXA-23-like, OXA-24-like, and OXA-58-like carbapenemases even when more than one is simultaneously present.

Review article: the safety of therapeutic drugs in male inflammatory bowel disease patients wishing to conceive.

BACKGROUND: Many therapeutic drugs are used by patients with inflammatory bowel disease, often around the time of conception. The pregnancy outcomes of males and females exposed to these therapeutics needs to be examined and this information is necessary to counsel patients appropriately. AIM: To review the literature describing male infertility and inflammatory bowel disease to educate practitioners of the impact of inflammatory bowel disease on male reproduction and the impact of therapeutics on pregnancy outcomes. METHODS: We performed a PubMed search using the search terms 'male infertility,' 'Crohn's disease,' 'inflammatory bowel disease,' 'ulcerative colitis,' 'ciprofloxacin AND infertility,' 'metronidazole AND infertility,' 'sulfasalazine AND infertility,' 'azathioprine AND infertility,' 'methotrexate AND infertility,' 'ciclosporin AND infertility,' 'corticosteroids AND infertility,' 'infliximab AND male fertility,' 'infliximab AND infertility,' 'infliximab AND foetus,' 'infliximab AND paternal exposure' and 'infliximab AND sperm.' References from selected papers were reviewed and used if relevant. RESULTS: Over half of male patients with IBD have some degree of infertility, compared to 8-17% of the general population. Semen parameters including total count, motility and morphology may be adversely affected by therapeutics. IBD medications in males do not increase foetal risk with the possible exception of azathioprine and mercaptopurine; however, increased foetal risk is seen in other drugs if taken by female patients. CONCLUSIONS: It is recognised that male infertility is often impacted with therapeutic drugs used to treat inflammatory bowel disease; however, the effects of the paternal drug exposure at the time of conception and exposure in utero should be considered to counsel patients appropriately.

Guidelines for the use of an insulin infusion for the management of hyperglycemia in critically ill patients

Objective: To evaluate the literature and identify important aspects of insulin therapy that facilitate safe and effective infusion therapy for a defined glycemic end point. Methods: Where available, the literature was evaluated using Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology to assess the impact of insulin infusions on outcome for general intensive care unit patients and those in specific subsets of neurologic injury, traumatic injury, and cardiovascular surgery. Elements that contribute to safe and effective insulin infusion therapy were determined through literature review and expert opinion. The majority of the literature supporting the use of insulin infusion therapy for critically ill patients lacks adequate strength to support more than weak recommendations, termed suggestions, such that the difference between desirable and undesirable effect of a given intervention is not always clear. Recommendations: The article is focused on a suggested glycemic control end point such that a blood glucose ≥150 mg/dL triggers interventions to maintain blood glucose below that level and absolutely <180 mg/dL. There is a slight reduction in mortality with this treatment end point for general intensive care unit patients and reductions in morbidity for perioperative patients, postoperative cardiac surgery patients, post-traumatic injury patients, and neurologic injury patients. We suggest that the insulin regimen and monitoring system be designed to avoid and detect hypoglycemia (blood glucose ≤70 mg/dL) and to minimize glycemic variability. Important processes of care for insulin therapy include use of a reliable insulin infusion protocol, frequent blood glucose monitoring, and avoidance of finger-stick glucose testing through the use of arterial or venous glucose samples. The essential components of an insulin infusion system include use of a validated insulin titration program, availability of appropriate staffing resources, accurate monitoring technology, and standardized approaches to infusion preparation, provision of consistent carbohydrate calories and nutritional support, and dextrose replacement for hypoglycemia prevention and treatment. Quality improvement of glycemic management programs should include analysis of hypoglycemia rates, run charts of glucose values <150 and 180 mg/dL. The literature is inadequate to support recommendations regarding glycemic control in pediatric patients. Conclusions: While the benefits of tight glycemic control have not been definitive, there are patients who will receive insulin infusion therapy, and the suggestions in this article provide the structure for safe and effective use of this therapy.

The yield of head CT in syncope: a pilot study.

UNLABELLED: Although head CT is often routinely performed in emergency department (ED) patients with syncope, few studies have assessed its value. OBJECTIVES: To determine the yield of routine head CT in ED patients with syncope and analyse the factors associated with a positive CT. METHODS: Prospective, observational, cohort study of consecutive patients presenting with syncope to an urban tertiary-care ED (48,000 annual visits). INCLUSION CRITERIA: age >or=18 and loss of consciousness (LOC). Exclusion criteria included persistent altered mental status, drug-related or post-trauma LOC, seizure or hypoglycaemia. Primary outcome was abnormal head CT including subarachnoid, subdural or parenchymal haemorrhage, infarction, signs of acute stroke and newly diagnosed brain mass. RESULTS: Of 293 eligible patients, 113 (39%) underwent head CT and comprise the study cohort. Ninety-five patients (84%) were admitted to the hospital. Five patients, 5% (95% CI=0.8%-8%), had an abnormal head CT: 2 subarachnoid haemorrhage, 2 cerebral haemorrhage and 1 stroke. Post hoc examination of patients with an abnormal head CT revealed focal neurologic findings in 2 and a new headache in 1. The remaining 2 patients had no new neurologic findings but physical findings of trauma (head lacerations with periorbital ecchymoses suggestive of orbital fractures). All patients with positive findings on CT were >65 years of age. Of the 108 remaining patients who had head CT, 45 (32%-51%) had signs or symptoms of neurologic disease including headache, trauma above the clavicles or took coumadin. Limiting head CT to this population would potentially reduce scans by 56% (47%-65%). If age >60 were an additional criteria, scans would be reduced by 24% (16%-32%). Of the patients who did not have head CT, none were found to have new neurologic disease during hospitalisation or 30-day follow-up. CONCLUSIONS: Our data suggest that the derivation of a prospectively derived decision rule has the potential to decrease the routine use of head CT in patients presenting to the ED with syncope.

Macroprolactin(s): composition and reactivity in immunoassays and laboratory interpretation of results of an unusual patient serum.

BACKGROUND: Macroprolactin is a high molecular mass complex of prolactin that may be the cause of elevated serum prolactin as determined by immunoassay. The composition of macroprolactin and its reactivity in immunoassays are variable but the complex has minimal bioactivity in vivo. Hyperprolactinaemia due to unrecognized macroprolactinaemia can lead to misdiagnosis and mistreatment. METHODS: Serum from a patient with an unusual pattern of immunoreactivity was distributed to three users of each of the most popular immunoassays represented in the UK National External Quality Assessment Scheme (NEQAS) for prolactin. Clinical details were provided and participating centres were invited to investigate the prolactin content of the specimen according to their local protocol, and to comment on their results. The nature of the macroprolactin in the specimen was investigated in detail by gel filtration chromatography of the native serum and of the serum after adsorption of IgG with protein A, and by affinity chromatography with concanavalin A. RESULTS: Gel filtration studies revealed two peaks of macroprolactin in this serum. These macroprolactins were shown to be different in their IgG content and degree of glycosylation. All eight immunoassays reacted strongly with the macroprolactin present. The majority (78%) of centres that interpreted their results either demonstrated the presence of macroprolactin in the specimen, or suggested it as a likely cause of the hyperprolactinaemia. However, two centres inappropriately excluded macroprolactinaemia as the cause of the elevated prolactin, and a further two did not consider it at all. Data from previous UK NEQAS distributions (between 1996 and 2003) of macroprolactin containing sera are presented which suggest that the frequency of recognition of macroprolactin as a possible cause of hyperprolactinaemia has increased over time. CONCLUSIONS: Very high molecular mass forms of prolactin and the presence of multiple molecular mass forms, as detected in the case presented here, are uncommon. Also, the pattern of immunoreactivity reported in this specimen was unusual as most macroprolactins studied previously react less strongly in, for example, the Bayer ADVIA Centaur assay compared to the Roche E170 assay. Both peaks of macroprolactin in this serum reacted in all assays tested. This case highlights the variable nature and immunoreactive behaviour of macroprolactin species.

Early vancomycin-resistant enterococcus (VRE) bacteremia after allogeneic bone marrow transplantation is associated with a rapidly deteriorating clinical course.

Vancomycin-resistant enterococcal (VRE) infection is a growing threat. We studied the incidence, risk factors, and clinical course of early-onset VRE bacteremia in allogeneic hematopoietic stem cell transplant recipients. We carried out a chart review of 281 allogeneic hematopoietic stem cell transplant recipients from 1997-2003, including preparative regimen, diagnosis, status of disease, graft-versus-host disease prophylaxis, antimicrobial therapy, and survival. VRE bacteremia developed in 12/281 (4.3%) recipients; 10 (3.6%) were within 21 days of transplant. Diagnoses were acute leukemia (7), NHL (2), and MDS (1). In all, 70% had refractory/relapsed disease; 30% were in remission. In total, 50% had circulating blasts. Nine of 10 had matched unrelated donors (7/9 with CD8+ T-cell depletion). The average time to positive VRE cultures was 15 days; average WBC was 0.05, and 80% had concomitant infections. Despite treatment, all patients died within 73 days of VRE bacteremia. Intra-abdominal complications were common. Causes of death included bacterial or fungal infection, multiorgan failure, VOD, ARDS, and relapse. A total of 60% of patients engrafted neutrophils, but none engrafted platelets. Early VRE bacteremia after allogeneic bone marrow transplant is associated with a rapidly deteriorating clinical course, although not always directly due to VRE. Early VRE may be a marker for the critical condition of these high-risk patients at the time of transplant.

Epidemiology of and surveillance for postpartum infections.

We screened automated ambulatory medical records, hospital and emergency room claims, and pharmacy records of 2,826 health maintenance organization (HMO) members who gave birth over a 30-month period. Full-text ambulatory records were reviewed for the 30-day postpartum period to confirm infection status for a weighted sample of cases. The overall postpartum infection rate was 6.0%, with rates of 7.4% following cesarean section and 5.5% following vaginal delivery. Rehospitalization; cesarean delivery; antistaphylococcal antibiotics; diagnosis codes for mastitis, endometritis, and wound infection; and ambulatory blood or wound cultures were important predictors of infection. Use of automated information routinely collected by HMOs and insurers allows efficient identification of postpartum infections not detected by conventional surveillance.

Changing patterns of presentations of patients with HIV-related disease at a tertiary referral centre and its implications for physician training.

Highly active antiretroviral therapy (HAART) has been shown to be highly effective in controlling HIV-related disease progression. Our objective was to determine whether HAART had altered the spectrum of HIV-related disease presentations at a tertiary medical referral centre and if a change in the clinical presentations of HIV-infected individuals to the hospital had impacted on physicians' training. A retrospective study which examined all admissions of HIV-infected patients identified between 1 October 1996 to 30 September 1998 using a hospital-designed computer database was undertaken at the Beth Israel Deaconess Medical Center (BIDMC) tertiary medical referral centre. All medical residents were surveyed in order to assess their knowledge of HIV-associated admissions and their confidence treating HIV-infected patients. There were significant changes in the admitting diagnosis for HIV-related illness between 1996 and 1998. Admissions for opportunistic infections (OIs) declined whereas admissions with bacterial infections increased significantly. Use of HAART remained stable between the 2 years of the study. Physicians' overestimated the use of HAART and only 8% of residents felt very comfortable taking care of an HIV-infected patient. In conclusion, the spectrum of presentations with HIV-related disease to a tertiary referral centre continues to change in the HAART era and impacts on physicians' experience of the management of HIV disease.

Automated methods for surveillance of surgical site infections.

Automated data, especially from pharmacy and administrative claims, are available for much of the U.S. population and might substantially improve both inpatient and postdischarge surveillance for surgical site infections complicating selected procedures, while reducing the resources required. Potential improvements include better sensitivity, less susceptibility to interobserver variation, more uniform availability of data, more precise estimates of infection rates, and better adjustment for patients' coexisting illness.

Preoperative drug dispensing as predictor of surgical site infection.

The system used by the National Nosocomial Infection Surveillance (NNIS) program to measure risk of surgical site infection uses a score of 3 on the American Society of Anesthesiologists (ASA)-physical status scale as a measure of underlying illness. The chronic disease score measures health status as a function of age, sex, and 29 chronic diseases, inferred from dispensing of prescription drugs. We studied the relationship between the chronic disease score and surgical site infection and whether the score can supplement the NNIS risk index. In a retrospective comparison of 191 patients with surgical site infection and 378 uninfected controls, the chronic disease score and ASA score were highly correlated. The chronic disease score improved prediction of infection by the NNIS risk index and augmented the ASA score for risk adjustment.

Occurrence of nosocomial bloodstream infections in six neonatal intensive care units.

BACKGROUND: Nosocomial bloodstream infections (NBSIs) occur frequently in neonatal intensive care units (NICUs) and are associated with substantial morbidity and mortality. Little has been published regarding variation in NBSI among institutions. OBJECTIVE: To determine NBSI incidence among six NICUs and to explore how much variation is explained by patient characteristics and NICU practice patterns. METHODS: From October, 1994, to June, 1996, six regional NICUs prospectively abstracted clinical records of all neonates weighing <1,500 g. Occurrence of NBSI, defined as first positive culture occurring >48 h after admission, was analyzed in relation to baseline patient characteristics and several common therapeutic interventions. Variables significant in univariate analyses were analyzed by Cox proportional hazards regression. RESULTS: There were 258 NBSIs (incidence, 19.1%) among 1,354 inborn first admissions. Incidence varied significantly by site, from 8.5 to 42%. Birth weight, Broviac catheter use and parenteral nutrition were significantly associated with NBSI (P < 0.05). When controlling for these variables interinstitutional variation in NBSI occurrence decreased but remained significant. CONCLUSIONS: Neonatal NBSI incidence varies substantially among institutions despite adjustment for length of stay and some known risk factors. The uses of Broviac catheters and especially intravenous nutrition supplements were significant determinants of NBSI risk.

Efficient identification of postdischarge surgical site infections: use of automated pharmacy dispensing information, administrative data, and medical record information.

Although most surgical site infections (SSIs) occur after hospital discharge, there is no efficient way to identify them. The utility of automated claims and electronic medical record data for this purpose was assessed in a cohort of 4086 nonobstetric procedures following which 96 postdischarge SSIs occurred. Coded diagnoses, tests, and treatments were assessed by use of recursive partitioning, with 10-fold cross-validation, and logistic regression with bootstrap resampling. Specific codes and combinations of codes identified a subset of 2% of all procedures among which 74% of SSIs had occurred. Accepting a specificity of 92% improved the sensitivity from 74% to 92%. Use of only hospital discharge diagnosis codes plus pharmacy dispensing data had sensitivity of 77% and specificity of 94%. All of these performance characteristics were better than questionnaire responses from patients or surgeons. Thus, information routinely collected by health care systems can be the basis of an efficient, largely passive, surveillance system for postdischarge SSIs.

Simplified surveillance for nosocomial bloodstream infections.

OBJECTIVE: To compare a surveillance definition of noso comial bloodstream infections requiring only microbiology data to the Centers for Disease Control and Prevention's (CDC) current definition. SETTING: Six teaching hospitals. METHODS: We classified a representative sample of 73 positive blood cultures from six hospitals growing common skin contaminant isolates using a definition for bacteremia requiring only microbiology data and the CDC definition for primary bloodstream infection (National Nosocomial Infections Surveillance [NNIS] System review method). The classifications assigned during routine prospective surveillance also were noted, and the time required to classify isolates by the two methods was compared. RESULTS: Among 65 blood cultures growing common skin contaminant isolates obtained from adults, the agreement rate between the microbiology data method and the NNIS review method was 91%. Agreement was significantly poorer for the eight blood cultures growing common skin contaminant isolates obtained from pediatric patients. The microbiology data method requires approximately 20 minutes less time per isolate than does routine surveillance. CONCLUSIONS: A definition based on microbiology data alone yields the same result as the CDC's definition in the large majority of instances. It is more resource-efficient than the CDC's current definition.