Healthcare-associated bacterial infections in the paediatric ICU.

BACKGROUND: An estimated 3.2 million patients annually develop healthcare-associated infections (HCAIs) in Europe alone amid the major challenge of increasing antimicrobial resistance. Critically ill children warrant specific evaluation because of differences in epidemiology, causative organisms and infection sites. OBJECTIVES: To examine the prevalence and antimicrobial susceptibility patterns of three types of HCAI in critically ill children and determine the effect on their disease course. MATERIALS AND METHODS: Retrospective cohort review of critically ill children admitted to a general paediatric ICU (PICU) at a regional academic tertiary referral centre over a 3 year period. RESULTS: There were 1930 admissions with a median age of 38 months. Children with HCAIs had a higher incidence of comorbidities (74% versus 24%) and a longer median length of stay (8 days versus 3 days). We identified 26 positive isolates (blood, lower respiratory and urine) taken 48 h or more after admission. The combined incidence was 1.34%. Hospital-acquired pneumonia accounted for 58% of HCAIs, urinary tract infections for 31% and bloodstream infections for 11%. The majority (61.5%) of HCAIs were caused by Gram-negative organisms. Seven isolates were resistant to antimicrobials used to treat HCAI. All of these were Gram-negative organisms (Pseudomonas aeruginosa, Klebsiella oxytoca and Escherichia coli). CONCLUSIONS: These data revealed a low incidence of HCAIs, 27% of which were resistant Gram-negative organisms. Critically ill children with HCAIs were more likely to have comorbidities and an increased length of stay. These factors may increasingly impact on PICU bed availability, an already limited resource.

Adherence to antibiotic guidelines and reported penicillin allergy: pooled cohort data on prescribing and allergy documentation from two English National Health Service (NHS) trusts.

OBJECTIVE: To investigate documentation of antimicrobial allergy and to determine prescribing adherence to local antibiotic guidelines for inpatients with and without reported penicillin allergy treated for infection in a National Health Service (NHS) context. SETTING: Data were collected at two English hospital NHS trusts over two time-periods: June 2016 and February 2017. DESIGN: Cohort study. Trust 1 data were sourced from prospective point prevalence surveys. Trust 2 data were extracted retrospectively from an electronic report. PARTICIPANTS: Inpatients treated for urinary tract infection (UTI), community-acquired pneumonia (CAP), hospital-acquired pneumonia (HAP) and skin and soft tissue infection (SSTI). Data on allergy were collected, and antibiotic selection assessed for adherence to trust guidelines with differences between groups presented as adjusted ORs. RESULTS: A total of 1497 patients were included, with 2645 antibiotics orders. Patients were treated for CAP (n=495; 33.1%), UTI (407; 27.2%), HAP (330; 22%) and SSTI (265; 17.7%). There were 240 (16%) patients with penicillin allergy. Penicillin allergy was recorded as allergy (n=52; 21.7%), side effect (27; 11.3%) and no documentation (161; 67.1%). Overall, 2184 (82.6%) antibiotic orders were guideline-adherent. Adherence was greatest for those labelled penicillin allergy (453 of 517; 87.6%) versus no allergy (1731 of 2128; 81.3%) (OR 0.52 (95% CI 0.37 to 0.73) p<0.001). Guideline-adherence for CAP was higher if penicillin allergy (151 of 163; 92.6%) versus no allergy (582 of 810; 71.9%) (OR 0.20 (95% CI 0.10 to 0.37) p<0.001). There was no difference in adherence between those with and without penicillin allergy for UTI, HAP or SSTI treatment. CONCLUSIONS: A relatively high proportion of patients had a penicillin allergy and two thirds of these had no description of their allergy, which has important implications for patient safety. Patients with penicillin allergy treated for CAP, received more guideline adherent antibiotics than those without allergy. Future studies investigating the clinical impact of penicillin allergy should include data on adherence to antibiotic guidelines.

Patient and public understanding and knowledge of antimicrobial resistance and stewardship in a UK hospital: should public campaigns change focus?

BACKGROUND: The rising global tide of antimicrobial resistance is a well-described phenomenon. Employing effective and innovative antimicrobial stewardship strategies is an essential approach to combat this public health threat. Education of the public and patients is paramount to enable the success of such strategies. METHODS: A panel of hospital multidisciplinary healthcare professionals was set up and a short quiz containing true/false statements around antimicrobial stewardship and resistance was designed and piloted. An educational leaflet with the correct replies and supporting information was also produced and disseminated. Participants were recruited on a single day (18 November 2015) from the hospital outpatient clinics and the hospital outpatient pharmacy waiting room. RESULTS: One hundred and forty-five completed quizzes were returned, providing a total of 1450 answers. Overall, 934 of 1450 (64%) statements were scored correctly whilst 481 (33%) were scored incorrectly; 35 (3%) statements were left unscored. We speculate that these results may demonstrate that respondents understood the statements, as only a small proportion of statements were left unanswered. The question dealing with the definition of antimicrobial resistance and the question dealing with the definition of antimicrobial stewardship obtained the most incorrect replies (85% and 72%, respectively). However, a specific factual recall question regarding only one microorganism (MRSA) received the most correct responses (99%). CONCLUSIONS: We describe a simple, innovative method of engagement with patients and the general public to help educate and disseminate important public health messages around antimicrobial resistance and stewardship. We also identified the need for public health campaigns to address the knowledge gaps found around this topic.

Emergence of host-adapted Salmonella Enteritidis through rapid evolution in an immunocompromised host.

Host adaptation is a key factor contributing to the emergence of new bacterial, viral and parasitic pathogens. Many pathogens are considered promiscuous because they cause disease across a range of host species, while others are host-adapted, infecting particular hosts(1). Host adaptation can potentially progress to host restriction, where the pathogen is strictly limited to a single host species and is frequently associated with more severe symptoms. Host-adapted and host-restricted bacterial clades evolve from within a broader host-promiscuous species and sometimes target different niches within their specialist hosts, such as adapting from a mucosal to a systemic lifestyle. Genome degradation, marked by gene inactivation and deletion, is a key feature of host adaptation, although the triggers initiating genome degradation are not well understood. Here, we show that a chronic systemic non-typhoidal Salmonella infection in an immunocompromised human patient resulted in genome degradation targeting genes that are expendable for a systemic lifestyle. We present a genome-based investigation of a recurrent blood-borne Salmonella enterica serotype Enteritidis (S. Enteritidis) infection covering 15 years in an interleukin-12 ß1 receptor-deficient individual that developed into an asymptomatic chronic infection. The infecting S. Enteritidis harboured a mutation in the mismatch repair gene mutS that accelerated the genomic mutation rate. Phylogenetic analysis and phenotyping of multiple patient isolates provides evidence for a remarkable level of within-host evolution that parallels genome changes present in successful host-restricted bacterial pathogens but never before observed on this timescale. Our analysis identifies common pathways of host adaptation and demonstrates the role that immunocompromised individuals can play in this process.

Exploring the coverage of antimicrobial stewardship across UK clinical postgraduate training curricula.

OBJECTIVES: Antimicrobial resistance (AMR) is a global political and patient safety issue. With ongoing strategic interventions to improve the shape of UK postgraduate clinical training, ensuring that all clinicians have appropriate knowledge and practical skills in the area of AMR is essential. To assess this, a cross-sectional analysis was undertaken of the coverage and quality of antimicrobial stewardship (AMS)/AMR within UK postgraduate clinical training curricula. METHODS: UK clinical specialty training curricula were identified. Topics and individual learning points relating to AMS or AMR were extracted for each specialty. Learning points were quality assessed against the expected level of clinical competence. Inter-specialty analysis was performed. RESULTS: Overall 37 specialties were assessed, equating to 2318 topics and 42 527 learning points. Of these, 8/2318 (0.3%) topics and 184/42 527 (0.4%) learning points were related to AMS/AMR. Infectious diseases represented all eight topics and 43/184 (23%) of the learning points. In contrast, primary care, which is responsible for the highest proportion of antimicrobial usage, had no topics and only 2/1368 (0.15%) of the AMS/AMR learning points. This paucity of representation was reflected across most of the remaining specialties. On quality assessment, the majority of learning points (111/184; 60%) required knowledge only, with no demonstration of behaviour in clinical practice required. CONCLUSIONS: Coverage of AMS/AMR is poor across the majority of UK postgraduate clinical training curricula, with little depth of learning required. Given the threat of AMR, and evolving changes in clinical training pathways, we call for cross-specialty action to address this current lack of engagement.

Emergence of host-adapted Salmonella Enteritidis through rapid evolution in an immunocompromised host.

Host adaptation is a key factor contributing to the emergence of new bacterial, viral and parasitic pathogens. Many pathogens are considered promiscuous because they cause disease across a range of host species, while others are host-adapted, infecting particular hosts1. Host adaptation can potentially progress to host restriction where the pathogen is strictly limited to a single host species and is frequently associated with more severe symptoms. Host-adapted and host-restricted bacterial clades evolve from within a broader host-promiscuous species and sometimes target different niches within their specialist hosts, such as adapting from a mucosal to a systemic lifestyle. Genome degradation, marked by gene inactivation and deletion, is a key feature of host adaptation, although the triggers initiating genome degradation are not well understood. Here, we show that a chronic systemic non-typhoidal Salmonella infection in an immunocompromised human patient resulted in genome degradation targeting genes that are expendable for a systemic lifestyle. We present a genome-based investigation of a recurrent blood-borne Salmonella enterica serotype Enteritidis (S. Enteritidis) infection covering 15 years in an interleukin (IL)-12 ß-1 receptor-deficient individual that developed into an asymptomatic chronic infection. The infecting S. Enteritidis harbored a mutation in the mismatch repair gene mutS that accelerated the genomic mutation rate. Phylogenetic analysis and phenotyping of multiple patient isolates provides evidence for a remarkable level of within-host evolution that parallels genome changes present in successful host-restricted bacterial pathogens but never before observed on this timescale. Our analysis identifies common pathways of host adaptation and demonstrates the role that immunocompromised individuals can play in this process.

Oxford Handbook of infectious diseases and microbiology

Forma variada do título - Infectious diseases and microbiology. Handbook of infectious diseases and microbiology.(AU)

First report of Salmonella enterica serotype paratyphi A azithromycin resistance leading to treatment failure.

The prevalence of Salmonella enterica serotype Paratyphi A infection is increasing, and multidrug resistance is a well-recognized problem. Resistance to fluoroquinolones is common and leads to more frequent use of newer agents like azithromycin. We report the first case of azithromycin resistance and treatment failure in a patient with S. Paratyphi A infection.

Comparison of two DNA microarrays for detection of plasmid-mediated antimicrobial resistance and virulence factor genes in clinical isolates of Enterobacteriaceae and non-Enterobacteriaceae.

A DNA microarray was developed to detect plasmid-mediated antimicrobial resistance (AR) and virulence factor (VF) genes in clinical isolates of Enterobacteriaceae and non-Enterobacteriaceae. The array was validated with the following bacterial species: Escherichiacoli (n=17); Klebsiellapneumoniae (n=3); Enterobacter spp. (n=6); Acinetobacter genospecies 3 (n=1); Acinetobacterbaumannii (n=1); Pseudomonasaeruginosa (n=2); and Stenotrophomonasmaltophilia (n=2). The AR gene profiles of these isolates were identified by polymerase chain reaction (PCR). The DNA microarray consisted of 155 and 133 AR and VF gene probes, respectively. Results were compared with the commercially available Identibac AMR-ve Array Tube. Hybridisation results indicated that there was excellent correlation between PCR and array results for AR and VF genes. Genes conferring resistance to each antibiotic class were identified by the DNA array. Unusual resistance genes were also identified, such as bla(SHV-5) in a bla(OXA-23)-positive carbapenem-resistant A. baumannii. The phylogenetic group of each E. coli isolate was verified by the array. These data demonstrate that it is possible to screen simultaneously for all important classes of mobile AR and VF genes in Enterobacteriaceae and non-Enterobacteriaceae whilst also assigning a correct phylogenetic group to E. coli isolates. Therefore, it is feasible to test clinical Gram-negative bacteria for all known AR genes and to provide important information regarding pathogenicity simultaneously.

Community-associated methicillin-resistant Staphylococcus aureus infections.

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has been recognized for over a decade, and usually refers to MRSA identified in previously healthy individuals with no recognized MRSA risk factors. Infections range from minor skin and soft tissue infections, through to severe pneumonia and necrotizing fasciitis. This review summarizes the current data on the epidemiology and molecular features of CA-MRSA, in addition to diagnosis and therapeutic measures. We also refer to current national guidelines for the management of these infections. Areas of agreement include the important genotypic and phenotypic differences of community MRSA strains compared with hospital strains. Areas of controversy include the precise epidemiological definition of community-acquired/associated MRSA. Fortunately, true CA-MRSA can be differentiated from hospital MRSA by molecular techniques, as discussed herein. Recent interest has focused on the changing epidemiology of CA-MRSA. Worldwide, CA-MRSA is now seen outside of the initial specific population groups, and in the USA, the successful USA300 community strain is beginning to spread back into hospitals. Reasons why USA300 remains relatively uncommon in Europe are unclear. Topics timely for research include the investigation of the epidemiology of infections and evolutionary genomics.

Ten years experience of Salmonella infections in Cambridge, UK.

OBJECTIVES: Review of all Salmonella infections diagnosed in the Cambridge area over 10 years. METHODS: All Salmonella enterica isolated in the Clinical Microbiology Laboratory, Addenbrooke's Hospital between 1.1.1999 and 31.12.2008 were included. Patient demographics, serotype and additional relevant details (travel history, resistance-type, phage-type) were recorded. RESULTS: 1003 episodes of Salmonella gastroenteritis were confirmed by stool culture, representing 88 serotypes. Serotypes Enteritidis (59%), Typhimurium (4.7%), Virchow (2.6%), Newport (1.8%) and Braenderup (1.7%) were the 5 most common isolates. There were an additional 37 invasive Salmonella infections (32 blood cultures, 4 tissue samples, 1 CSF). 13/15 patients with Salmonella Typhi or Salmonella Paratyphi isolated from blood or faeces with an available travel history had returned from the Indian subcontinent. 8/10 S. Typhi or Paratyphi isolates tested had reduced susceptibility to fluoroquinolones (MIC > or = 0.125 mg/L). 7/21 patients with non-typhoidal Salmonella bacteraemia were known to be immunosuppressed. CONCLUSION: This study describes Salmonella serotypes circulating within a defined geographical area over a decade. Prospective molecular analysis of isolates of S. enterica by multi-locus sequence typing (MLST) and single nucleotide polymorphism (SNP) detection will determine the geo-phylogenetic relationship of isolates within our region.

Report of neonatal meningitis due to Salmonella enterica serotype Agona and review of breast milk-associated neonatal Salmonella infections.

We present the first documented case of Salmonella enterica serotype Agona meningitis in a 6-day-old baby. S. enterica serotype Agona was isolated concurrently from infant cerebrospinal fluid and parental fecal samples, and Salmonella was isolated from breast milk. The role of breast milk in transmission of Salmonella enterica is discussed.

First report of human infection with Salmonella enterica serovar Apapa resulting from exposure to a pet lizard.

We present the first documented human case of Salmonella enterica serovar Apapa infection, isolated concurrently from a hospital inpatient and a pet lizard. The isolates were identical by biochemical profiling and pulsed-field gel electrophoresis. This rare serotype is known to be associated with reptiles. The current practice for avoiding reptile-associated infections is reviewed.

Fever, a blue hand, and abducens nerve paralysis in a returning traveler.

Fever, caused by Salmonella typhi, is the cause of significant morbidity worldwide. Extraintestinal manifestations of typhoid fever can confuse clinicians in Western countries, delaying diagnosis. We present an extraordinary case of typhoid fever, manifesting as hand cyanosis as well as abducens nerve paresis, all of which promptly resolved with antibiotics.

Variation in Salmonella enterica serovar typhi IncHI1 plasmids during the global spread of resistant typhoid fever.

A global collection of plasmids of the IncHI1 incompatibility group from Salmonella enterica serovar Typhi were analyzed by using a combination of DNA sequencing, DNA sequence analysis, PCR, and microarrays. The IncHI1 resistance plasmids of serovar Typhi display a backbone of conserved gene content and arrangement, within which are embedded preferred acquisition sites for horizontal DNA transfer events. The variable regions appear to be preferred acquisition sites for DNA, most likely through composite transposition, which is presumably driven by the acquisition of resistance genes. Plasmid multilocus sequence typing, a molecular typing method for IncHI1 plasmids, was developed using variation in six conserved loci to trace the spread of these plasmids and to elucidate their evolutionary relationships. The application of this method to a collection of 36 IncHI1 plasmids revealed a chronological clustering of plasmids despite their difference in geographical origins. Our findings suggest that the predominant plasmid types present after 1993 have not evolved directly from the earlier predominant plasmid type but have displaced them. We propose that antibiotic selection acts to maintain resistance genes on the plasmid, but there is also competition between plasmids encoding the same resistance phenotype.

Characterization of the genomes of a diverse collection of Salmonella enterica serovar Typhimurium definitive phage type 104.

Salmonella enterica serovar Typhimurium definitive phage type 104 (DT104) has caused significant morbidity and mortality in humans and animals for almost three decades. We completed the full DNA sequence of one DT104 strain, NCTC13348, and showed that significant differences between the genome of this isolate and the genome of the previously sequenced strain Salmonella serovar Typhimurium LT2 are due to integrated prophage elements and Salmonella genomic island 1 encoding antibiotic resistance genes. Thirteen isolates of Salmonella serovar Typhimurium DT104 with different pulsed-field gel electrophoresis (PFGE) profiles were analyzed by using multilocus sequence typing (MLST), plasmid profiling, hybridization to a pan-Salmonella DNA microarray, and prophage-based multiplex PCR. All the isolates belonged to a single MLST type, sequence type ST19. Microarray data demonstrated that the gene contents of the 13 DT104 isolates were remarkably conserved. The PFGE DNA fragment size differences in these isolates could be explained to a great extent by differences in the prophage and plasmid contents. Thus, here the nature of variation in different Salmonella serovar Typhimurium DT104 isolates is further defined at the gene and whole-genome levels, illustrating how this phage type evolves over time.

The missing care bundle: antibiotic prescribing in hospitals.

The care bundle involves grouping together key elements of care for procedures and the management of specific diagnoses in order to provide a systematic method to improve and monitor the delivery of clinical care processes. In short, care bundles aim to ensure that all patients consistently receive the best care or treatment, all of the time. This approach has been successfully applied to the management of various conditions, particularly in the critical care setting. The Institute for Healthcare Improvement's '100K lives campaign' consisted of six care bundles, three of which have addressed preventing hospital-acquired infection. The UK Department of Health's delivery programme to reduce healthcare-associated infections (HCAIs), including methicillin-resistant Staphylococcus aureus (MRSA), includes six 'high-impact interventions', which are care bundles to reduce HCAIs. However, we suggest that one key intervention is missing, and consider this intervention will be increasingly important if hospitals are to address the rising incidence of Clostridium difficile, to tackle antibiotic resistance and to improve patient care. The missing intervention addresses the process of antibiotic prescribing. We propose that the time is right to consider the application of the care bundle approach to improve the prescribing of antibiotics, both for treatment and prophylaxis.

Prophage sequences defining hot spots of genome variation in Salmonella enterica serovar Typhimurium can be used to discriminate between field isolates.

Sixty-one Salmonella enterica serovar Typhimurium isolates of animal and human origin, matched by phage type, antimicrobial resistance pattern, and place of isolation, were analyzed by microbiological and molecular techniques, including pulsed-field gel electrophoresis (PFGE) and plasmid profiling. PFGE identified 10 profiles that clustered by phage type and antibiotic resistance pattern with human and animal isolates distributed among different PFGE profiles. Genomic DNA was purified from 23 representative strains and hybridized to the composite Salmonella DNA microarray, and specific genomic regions that exhibited significant variation between isolates were identified. Bioinformatic analysis showed that variable regions of DNA were associated with prophage-like elements. Subsequently, simple multiplex PCR assays were designed on the basis of these variable regions that could be used to discriminate between S. enterica serovar Typhimurium isolates from the same geographical region. These multiplex PCR assays, based on prophage-like elements and Salmonella genomic island 1, provide a simple method for identifying new variants of S. enterica serovar Typhimurium in the field.

Cases of typhoid fever imported into England, Scotland and Wales (2000-2003).

Although typhoid fever is no longer endemic in most of the developed world, it remains a major infectious disease in less developed regions and imported cases continue to occur in returning travellers, immigrants or migrant workers. We analysed all 692 isolates of Salmonella enterica subspecies enterica serovar Typhi from cases in England, Scotland and Wales that were sent to the Laboratory of Enteric Pathogens at the Health Protection Agency, Centre for Infections, London, UK between 2000 and 2003. The country of acquisition was known for 416 isolates (60%), and the majority of these (70%) came from India or Pakistan. Overall, 24 countries were listed, mainly in Asia and Africa. A total of 48 phage types were detected, 41% of which were Vi-phage type E1. Antimicrobial susceptibility testing revealed that 22% of isolates were multidrug resistant (MDR) (defined as resistance to chloramphenicol, ampicillin and co-trimoxazole) and 39% were quinolone resistant. A significant number of isolates (n=49) were sensitive to nalidixic acid by disk test but exhibited low-level ciprofloxacin resistance, suggesting a novel mechanism of resistance and reinforcing the need for minimum inhibitory concentration determination. Overall, 13% of isolates were both MDR and likely to show a poor response to a fluoroquinolone. A third-generation cephalosporin (e.g. ceftriaxone) should be considered as empirical therapy in regions of the Indian subcontinent where resistance is now at high levels as well as in patients returning from these areas. This study helps to describe the epidemiology of antimicrobial drug resistance in typhoid fever.