National Nosocomial Infections Surveillance (NNIS) System Report, Data Summary from January 1990-May 1999, issued June 1999. A report from the

Urinary tract infections and catheter-associated urinary tract infections caused by Pseudomonas aeruginosa

SUMMARYUrinary tract infection (UTI) is one of the most common infections in otherwise healthy individuals. UTI is also common in healthcare settings where patients often require urinary catheters to alleviate urinary retention. The placement of a urinary catheter often leads to catheter-associated urinary tract infection (CAUTI) caused by a broad range of opportunistic pathogens, commonly referred to as ESKAPE (Enterococcus, Staphylococcus, Klebsiella, Acinetobacter, Pseudomonas, and Enterobacter) pathogens. Our understanding of CAUTI is complicated by the differences in pathogens, in initial microbial load, changes that occur due to the duration of catheterization, and the relationship between infection (colonization) and disease symptoms. To advance our understanding of CAUTI, we reviewed UTI and CAUTI caused by Pseudomonas aeruginosa which is unique in that it is not commonly found associated with human microbiomes. For this reason, the ability of P. aeruginosa to cause UTI and CAUTI requires the introduction of the bacteria to the bladder from catheterization. Once in the host, the virulence factors used by P. aeruginosa in these infections remain an area of ongoing research. In this review, we will discuss studies that focus on P. aeruginosa UTI and CAUTI to better understand the infection dynamics and outcome in clinical settings, virulence factors associated with P. aeruginosa isolated from the urinary tract, and animal studies to test which bacterial factors are required for this infection. Understanding how P. aeruginosa can cause UTI and CAUTI can provide an understanding of how these infections initiate and progress and may provide possible strategies to limit these infections.

Guidelines for Antibiotics Prescription in Critically Ill Patients

How to cite this article: Khilnani GC, Tiwari P, Mittal S, Kulkarni AP, Chaudhry D, Zirpe KG, et al. Guidelines for Antibiotics Prescription in Critically Ill Patients. Indian J Crit Care Med 2024;28(S2):S104-S216.

Comprehensive genomic landscape of antibiotic resistance in Staphylococcus epidermidis

Staphylococcus epidermidis, a common commensal bacterium found on human skin, can cause infections in clinical settings, and the presence of antibiotic resistance genes (ARGs) impedes the treatment of S. epidermidis infections. However, studies characterizing the ARGs in S. epidermidis with regard to genomic and ecological diversities are limited. Thus, we performed a comprehensive and comparative analysis of 405 high-quality S. epidermidis genomes, including those of 35 environmental isolates from the Han River, to investigate the genomic diversity of antibiotic resistance in this pathogen. Comparative genomic analysis revealed the prevalence of ARGs in S. epidermidis genomes associated with multi-locus sequence types. The genes encoding dihydrofolate reductase (dfrC) and multidrug efflux pump (norA) were genome-wide core ARGs. β-Lactam class ARGs were also highly prevalent in the S. epidermidis genomes, which was consistent with the resistance phenotype observed in river isolates. Furthermore, we identified chloramphenicol acetyltransferase genes (cat) in the plasmid-like sequences of the six river isolates, which have not been reported previously in S. epidermidis genomes. These genes were identical to those harbored by the Enterococcus faecium plasmids and associated with the insertion sequence 6 family transposases, homologous to those found in Staphylococcus aureus plasmids, suggesting the possibility of horizontal gene transfer between these Gram-positive pathogens. Comparison of the ARG and virulence factor profiles between S. epidermidis and S. aureus genomes revealed that these two species were clearly distinguished, suggesting genomic demarcation despite ecological overlap. Our findings provide a comprehensive understanding of the genomic diversity of antibiotic resistance in S. epidermidis.

IMPORTANCE

A comprehensive understanding of the antibiotic resistance gene (ARG) profiles of the skin commensal bacterium and opportunistic pathogen Staphylococcus epidermidis needs to be documented from a genomic point of view. Our study encompasses a comparative analysis of entire S. epidermidis genomes from various habitats, including those of 35 environmental isolates from the Han River sequenced in this study. Our results shed light on the distribution and diversity of ARGs within different S. epidermidis multi-locus sequence types, providing valuable insights into the ecological and genetic factors associated with antibiotic resistance. A comparison between S. epidermidis and Staphylococcus aureus revealed marked differences in ARG and virulence factor profiles, despite their overlapping ecological niches.

Co-colonization of methicillin-resistant Staphylococcus aureus and Candida spp. in children with malignancies

This study aimed to evaluate the interaction between methicillin-resistant Staphylococcus aureus(MRSA) and Candida spp. in the oral cavity of children with malignancies under chemotherapy. We evaluated the expression level of Als3p and mecA in Candida spp. and MRSA strains in both single colonization and co-colonization condition. Oral and nasal samples were collected by dry sponge swabs in 10 ml of sterile phosphate-buffered saline. The MRSA and Candida spp. was confirmed using the PCR method and mecA and Als3p genes, respectively. The SYBR Green-based quantitative real-time PCR was used to evaluate the relative expression levels of mecA and Als3p genes in MRSA and Candida spp., respectively. The frequency of S. aureus in oral-only and nasal-only swab samples were 14.1% (n = 24/170). 58.3% (n = 14/24) and 29.2% (n = 7/24) of S. aureus isolated from oral and nasal samples were MRSA, respectively. Among Candida species, C. albicans (n = 28/170; 16.5%) had the highest frequency. The oral co-colonization of MRSA and Candida spp. was detected in 4.7% (n = 8/170) patients. The overall average of gene expression levels among all Candida spp. and MRSA isolates indicated that the mecA and Als3p genes expression increased six and two times in co-colonization conditions compared to single colonization conditions, respectively. Our findings revealed the importance of polymicrobial infection in clinical settings and stated that it is possible that Candida spp. facilitates the infection of S. aureus and can lead to systemic infection in co-colonized patients.

Technical Feasibility and Safety of Central Venous Ports for Intravenous Chemotherapy in Infants With Retinoblastoma: A Retrospective Study

PURPOSE

The central venous port (CVP) is widely used for intravenous chemotherapy (IVC) in adult patients because of its lower infection rates and easier management than that of a central venous catheter. However, the feasibility and safety of the CVP for IVC in infants remain unknown. This study evaluated the usefulness of CVP for IVC in infants with retinoblastoma.

METHODS

The usefulness of CVP was retrospectively evaluated using technical success rates, the safety of CVP placement, and postoperative procedure-related complications in 18 infants with retinoblastoma. This study was conducted at the National Cancer Center Hospital, Chuo-Ku, Tokyo, Japan.

RESULTS

The technical success rate was 100% (18/18) without any procedure-related complications. The sum duration of CVP implantation was 12,836 days (mean: 713 ± 453 days, range: 10-1,639 days). Postoperative complications were observed in two cases; one was a port reversal after 20 days, which was reversed by incisional surgery, and another was a catheter-related bloodstream infection after eight days, resulting in CVP removal. The total incidence of CVP-related infections was 5.6% (1/18) and 0.08/1000 catheter days. No other CVP-related complications were noted.

CONCLUSION

The use of the CVP for IVC in infants with retinoblastoma was feasible with few complications.

Applying the standardized infection ratio for reporting surgical site infections in Australian healthcare facilities

Objective

We explored the utility of the standardized infection ratio (SIR) for surgical site infection (SSI) reporting in an Australian jurisdiction.

Design

Retrospective chart review.

Setting

Statewide SSI surveillance data from 2013 to 2019.

Patients

Individuals who had cardiac bypass surgery (CABG), colorectal surgery (COLO), cesarean section (CSEC), hip prosthesis (HPRO), or knee prosthesis (KPRO) procedures.

Methods

The SIR was calculated by dividing the number of observed infections by the number of predicted infections as determined using the National Healthcare Safety Network procedure-specific risk models. In line with a minimum precision criterion, an SIR was not calculated if the number of predicted infections was <1.

Results

A SIR >0 (≥1 observed SSI, predicted number of SSI ≥1, no missing covariates) could be calculated for a median of 89.3% of reporting quarters for CABG, 75.0% for COLO, 69.0% for CSEC, 0% for HPRO, and 7.1% for KPRO. In total, 80.6% of the reporting quarters, when the SIR was not calculated, were due to no observed infections or predicted infections <1, and 19.4% were due to missing covariates alone. Within hospitals, the median percentage of quarters during which zero infections were observed was 8.9% for CABG, 20.0% for COLO, 25.4% for CSEC, 67.3% for HPRO, and 71.4% for KPRO.

Conclusions

Calculating an SIR for SSIs is challenging for hospitals in our regional network, primarily because of low event numbers and many facilities with predicted infections <1. Our SSI reporting will continue to use risk-indexed rates, in tandem with SIR values when predicted number of SSI ≥1.

Enterobacter cloacae infection characteristics and outcomes in battlefield trauma patients

Enterobacter cloacae is a Gram-negative rod with multidrug-resistant potential due to chromosomally-induced AmpC β-lactamase. We evaluated characteristics, antibiotic utilization, and outcomes associated with battlefield-related E. cloacae infections (2009-2014). Single initial and serial E. cloacae isolates (≥24 hours from initial isolate from any site) associated with a clinical infection were examined. Susceptibility profiles of initial isolates in the serial isolation group were contrasted against last isolate recovered. Characteristics of 112 patients with E. cloacae infections (63 [56%] with single initial isolation; 49 [44%] with serial isolation) were compared to 509 patients with bacterial infections not attributed to E. cloacae. E. cloacae patients sustained more blast trauma (78%) compared to non-E. cloacae infections patients (75%; p<0.001); however, injury severity scores were comparable (median of 34.5 and 33, respectively; p = 0.334). Patients with E. cloacae infections had greater shock indices (median 1.07 vs 0.92; p = 0.005) and required more initial blood products (15 vs. 14 units; p = 0.032) compared to patients with non-E. cloacae infections. Although E. cloacae patients had less intensive care unit admissions (80% vs. 90% with non-E. cloacae infection patients; p = 0.007), they did have more operating room visits (5 vs. 4; p = 0.001), longer duration of antibiotic therapy (43.5 vs. 34 days; p<0.001), and lengthier hospitalizations (57 vs. 44 days; p<0.001). Patients with serial E. cloacae had isolation of infecting isolates sooner than patients with single initial E. cloacae (median of 5 vs. 8 days post-injury; p = 0.046); however, outcomes were not significantly different between the groups. Statistically significant resistance to individual antibiotics did not develop between initial and last isolates in the serial isolation group. Despite current combat care and surgical prophylaxis guidelines recommending upfront provision of AmpC-inducing antibiotics, clinical outcomes did not differ nor did significant antibiotic resistance develop in patients who experienced serial isolation of E. cloacae versus single initial isolation.

Inter-species diversity and functional genomic analyses of closed genome assemblies of clinically isolated, megaplasmid-containing Enterococcus raffinosus Er676 and ATCC49464

Enterococcus raffinosus is an understudied member of its genus possessing a characteristic megaplasmid contributing to a large genome size. Although less commonly associated with human infection compared to other enterococci, this species can cause disease and persist in diverse niches such as the gut, urinary tract, blood and environment. Few complete genome assemblies have been published to date for E. raffinosus . In this study, we report the complete assembly of the first clinical urinary E. raffinosus strain, Er676, isolated from a postmenopausal woman with history of recurrent urinary tract infection. We additionally completed the assembly of clinical type strain ATCC49464. Comparative genomic analyses reveal inter-species diversity driven by large accessory genomes. The presence of a conserved megaplasmid indicates it is a ubiquitous and vital genetic feature of E. raffinosus . We find that the E. raffinosus chromosome is enriched for DNA replication and protein biosynthesis genes while the megaplasmid is enriched for transcription and carbohydrate metabolism genes. Prophage analysis suggests that diversity in the chromosome and megaplasmid sequences arises, in part, from horizontal gene transfer. Er676 demonstrated the largest genome size reported to date for E. raffinosus and the highest probability of human pathogenicity. Er676 also possesses multiple antimicrobial resistance genes, of which all but one are encoded on the chromosome, and has the most complete prophage sequences. Complete assembly and comparative analyses of the Er676 and ATCC49464 genomes provide important insight into the inter-species diversity of E. raffinosus that gives it its ability to colonize and persist in the human body. Investigating genetic factors that contribute to the pathogenicity of this species will provide valuable tools to combat diseases caused by this opportunistic pathogen.

Systematic Review of Incidence Studies of Pneumonia in Persons with Spinal Cord Injury

Pneumonia continues to complicate the course of spinal cord injury (SCI). Currently, clinicians and policy-makers are faced with only limited numbers of pneumonia incidence in the literature. A systematic review of the literature was undertaken to provide an objective synthesis of the evidence about the incidence of pneumonia in persons with SCI. Incidence was calculated per 100 person-days, and meta-regression was used to evaluate the influence of the clinical setting, the level of injury, the use of mechanical ventilation, the presence of tracheostomy, and dysphagia. For the meta-regression we included 19 studies. The incidence ranged from 0.03 to 7.21 patients with pneumonia per 100 days. The main finding of this review is that we found large heterogeneity in the reporting of the incidence, and we therefore should be cautious with interpreting the results. In the multivariable meta-regression, the incidence rate ratios showed very wide confidence intervals, which does not allow a clear conclusion concerning the risk of pneumonia in the different stages after a SCI. Large longitudinal studies with a standardized reporting on risk factors, pneumonia, and detailed time under observation are needed. Nevertheless, this review showed that pneumonia is still a clinically relevant complication and pneumonia prevention should focus on the ICU setting and patients with complete tetraplegia.

Interplay between Candida albicans and Lactic Acid Bacteria in the Gastrointestinal Tract: Impact on Colonization Resistance, Microbial Carriage, Opportunistic Infection, and Host Immunity

Emerging studies have highlighted the disproportionate role of Candida albicans in influencing both early community assembly of the bacterial microbiome and dysbiosis during allergic diseases and intestinal inflammation. Nonpathogenic colonization of the human gastrointestinal (GI) tract by C. albicans is common, and the role of this single fungal species in modulating bacterial community reassembly after broad-spectrum antibiotics can be readily recapitulated in mouse studies. One of the most notable features of C. albicans-associated dysbiotic states is a marked change in the levels of lactic acid bacteria (LAB). C. albicans and LAB share metabolic niches throughout the GI tract, and in vitro studies have identified various interactions between these microbes. The two predominant LAB affected are Lactobacillus species and Enterococcus species. Lactobacilli can antagonize enterococci and C. albicans, while Enterococcus faecalis and C. albicans have been reported to exhibit a mutualistic relationship. E. faecalis and C. albicans are also causative agents of a variety of life-threatening infections, are frequently isolated together from mixed-species infections, and share certain similarities in clinical presentation-most notably their emergence as opportunistic pathogens following disruption of the microbiota. In this review, we discuss and model the mechanisms used by Lactobacillus species, E. faecalis, and C. albicans to modulate each other's growth and virulence in the GI tract. With multidrug-resistant E. faecalis and C. albicans strains becoming increasingly common in hospital settings, examining the interplay between these three microbes may provide novel insights for enhancing the efficacy of existing antimicrobial therapies.

Duplex dPCR System for Rapid Identification of Gram-Negative Pathogens in the Blood of Patients with Bloodstream Infection: A Culture-Independent Approach

Early and accurate detection of pathogens is important to improve clinical outcomes of bloodstream infections (BSI), especially in the case of drug-resistant pathogens. In this study, we aimed to develop a culture-independent digital PCR (dPCR) system for multiplex detection of major sepsiscausing gram-negative pathogens and antimicrobial resistance genes using plasma DNA from BSI patients. Our duplex dPCR system successfully detected nine targets (five bacteria-specific targets and four antimicrobial resistance genes) through five reactions within 3 hours. The minimum detection limit was 50 ag of bacterial DNA, suggesting that 1 CFU/ml of bacteria in the blood can be detected. To validate the clinical applicability, cell-free DNA samples from febrile patients were tested with our system and confirmed high consistency with conventional blood culture. This system can support early identification of some drug-resistant gram-negative pathogens, which can help improving treatment outcomes of BSI.

Dynamic Adaptive Response of Pseudomonas aeruginosa to Clindamycin/Rifampicin-Impregnated Catheters

Pseudomonas aeruginosa is the most common Gram-negative pathogen causing nosocomial multidrug resistant infections. It is a good biofilm producer and has the potential for contaminating medical devices. Despite the widespread use of antibacterial-impregnated catheters, little is known about the impacts of antibacterial coating on the pathogenesis of P. aeruginosa. In this study, we investigated the adaptive resistance potential of P. aeruginosa strain PAO1 in response to continuous antibiotic exposure from clindamycin/rifampicin-impregnated catheters (CR-IC). During exposure for 144 h to clindamycin and rifampicin released from CR-IC, strain PAO1 formed biofilms featuring elongated and swollen cells. There were 545 and 372 differentially expressed proteins (DEPs) identified in the planktonic and biofilm cells, respectively, by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Both Cluster of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that the planktonic cells responded to the released antibiotics more actively than the biofilm cells, with metabolism and ribosomal biosynthesis-associated proteins being significantly over-expressed. Exposure to CR-IC increased the invasion capability of P. aeruginosa for Hela cells and upregulated the expression of certain groups of virulence proteins in both planktonic and biofilm cells, including the outer membrane associated (flagella, type IV pili and type III secretion system) and extracellular (pyoverdine) virulence proteins. Continuous exposure of P. aeruginosa to CR-IC also induced the overexpression of antibiotic resistance proteins, including porins, efflux pumps, translation and transcription proteins. However, these upregulations did not change phenotypic minimum inhibitory concentration (MIC) during the experimental timeframe. The concerning association between CR-IC and overexpression of virulence factors in P. aeruginosa suggests the need for additional investigation to determine if it results in adverse clinical outcomes.

A retrospective cross-sectional survey on nosocomial bacterial infections and their antimicrobial susceptibility patterns in hospitalized patients in northwest of Iran

Objective

Nosocomial infections (NIs) are known as one of the remarkable problems in all countries. This study is aimed to estimate the prevalence rate of nosocomial bacterial agents with antimicrobial susceptibility pattern in hospitalized patients. This study was conducted from April 2017 to September 2018, on 4029 hospitalized patients. We set out to recognize the commonest bacterial infections and antimicrobial susceptibility patterns of nosocomial infection.

Results

Of the 4029 patients, 509 (12.6%) of them were culture positive. Of these Escherichia coli (E. coli) (98.3%) and Staphylococcus epidermidis (S. epidermidis) (37.5%) were the most abundant bacterial identified in the urinary tract and bloodstream cultures respectively, Moreover, Acinetobacter spp. (100%) and Pseudomonas aeruginosa (22.2%) were the most abundant organisms detected in the respiratory system. According to susceptibility testing results, 370 (80.5%) and 264 (57.3%) in Gram-negatives and 44 (91.7%) and 35 (72.9%) in gram positives isolated strains were classified as multidrug-resistant (MDR) and extensive drug-resistant (XDR) strain respectively. On account of the high prevalence of MDR and XDR bacterial species, there is a pressing need for the expansion of new strategies on antibiotic supervision and infection control to introduce new guideline on empirical antibiotic therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-021-05503-0.

Features, Pharmacological Chemistry, Molecular Mechanism and Health Benefits of Lemon

Background:

Citrus limon, a Mediterranean-grown citrus species of plants belonging to the Rutaceae family, occupies a place of an impressive range of food and medicinal uses with considerable value in the economy of the fruit of the country. Citrus fruits are economically important with large-scale production of both the fresh fruits and industrially processed products. The extracts and phytochemicals obtained from all parts of C. limon have shown immense therapeutic potential because of their anticancer, anti-tumor and anti-inflammatory nature, and also serve as an important ingredient in the formulation of several ethnic herbal medicines. These properties are mediated by the presence of different phytochemicals, vitamins and nutrients in the citrus fruits.

Material and Methods:

The methods involved in the preparation of the present article included the collection of information from various scientific databases, indexed periodicals, and search engines such as Medline Scopus google scholar PubMed, PubMed central web of science, and science direct.

Results:

This communication presents an updated account of different pharmacological aspects of C. limon associated with its anti-oxidative, antiulcer, antihelmintic, insecticidal, anticancer, cytotoxic, and estrogenic activities. In addition, C. limon extracts possess hepatoprotective, anti-hyperglycemic, and antimicrobial properties. The present article includes the structure and function of different key chemical constituents from different parts of C. limon. Also, the possible molecular mechanisms of actions of bioactive compounds from C. limon are displayed.

Conclusion:

The traditional and ethno-medicinal literature revealed that C. limon is very effective in different pathologies. Most of these compounds possessing antioxidant properties would be implicated in offering health benefits by acting as potential nutraceuticals to humans with special reference to disease management of health and disease.

A descriptive analysis of PVL-positive multidrug-resistant Staphylococcus aureus in hospital-associated infections in Saudi Arabia

Methicillin resistant Staphylococcus aureus infections impose a huge risk to public health in healthcare and community settings worldwide. Therefore, it is of interest to document data on the anti-biogramas and genotypes of isolates from Saudi Arabia. We assessed the antimicrobial susceptibility, determined spa (protein A gene) and analyzed multilocus MLST genotypes, and detected PVL gene in these isolates. We collected 28 clinical MRSA isolates, cultured and determined the minimum inhibitory concentrations of 17 antimicrobial agents using Vitek2 system (BioMerieux, USA) from 3 hospitals in Saudi Arabia during the year 2012. Polymorphic region of the spa and seven housekeeping genes were amplified and sequenced. BioNumerics v.5.1 (Applied Maths) was used for spa typing and MLST. Samples were screened for the presence of PVL and mecA genes using polymerase chain reaction (PCR). Analysis shows that all isolates were susceptible to chloramphenicol, rifampicin, nitrofurantoin, teicoplanin, daptomycin and vancomycin. The T4573/ST22 strains are found to be prevalent in the Saudi Arabia (N=6, 21%). We further noted that three isolates (t363/ST240 strain) were resistant to eight antimicrobial agents. Most of t4573/ST22 strains were PVL positive, resistant to ciprofloxacin and linked to HA-MRSA infections. We document data for the presence of emerging multi drug resistant S. aureus strains carrying the PVL gene circulating within hospitals. This highlights the urgent need for continuous active surveillance and implementation of prevention measures.

Characterization of φEf-vB1 prophage infecting oral Enterococcus faecalis and enhancing bacterial biofilm formation

Introduction. Enterococcus faecalis is a facultative, anaerobic, opportunistic pathogen associated with medical and dental diseases. Bacterial phenotypic traits and pathogenesis are often influenced by lysogeny.Aim. The aim of this study was to characterize both the morphology and complete genome sequences of induced prophages purified from E. faecalis clinical isolates.Methodology. E. faecalis isolates were recovered from the roots of teeth of patients attending an endodontic clinic. The morphological features of isolated phage were characterized using transmission electron microscopy (TEM). DNA sequencing was performed using the Illumina MiSeq platform.Results. TEM indicated that the isolated φEf-vB1 prophage belongs to the family Siphoviridae. The φEf-vB1 prophage was stable over a wide range of temperatures and pH. Sequencing of φEf-vB1 DNA revealed that the phage genome is 37 561 bp in length with a G+C content of 37.6mol% and contained 53 ORFs. Comparison with previously predicted prophage genomes using blast revealed that φEf-vB1 has a high sequence similarity to previously characterized phage genomes. The lysogenic E. faecalis strain exhibited a higher biofilm formation capacity relative to the non-lysogenic strain.Conclusion. The current findings highlight the role of lysogeny in modification of E. faecalis properties and reveal the potential importance of prophages in E. faecalis biology and pathogenesis.

Topical povidone iodine inhibits bacterial growth in the oral cavity of patients on mechanical ventilation: a randomized controlled study

Background

Topical 0.12% chlorhexidine has been used widely to prevent ventilator-associated pneumonia in patients undergoing mechanical ventilation. However, it is not approved for mucosal application in Japan. The aims of this study were to investigate if topical povidone iodine (i) inhibits bacterial growth and (ii) disrupts the balance of the oral microbiota.

Methods

This randomized controlled clinical trial included 23 patients who underwent mechanical ventilation in the intensive care unit. The patients were divided randomly into two groups: the intervention group (n = 16) and the control group (n = 7). All patients received oral cleaning with 3% hydrogen peroxide, followed by irrigation with tap water. The patients in the intervention group received 10% povidone iodine applied topically to the oral cavity. The concentration of total bacteria in the oropharyngeal fluid were determined before, immediately after, 1 h, 2 h, and 3 h after oral care using the Rapid Oral Bacteria Quantification System, which is based on dielectrophoresis and impedance measurements. The number of streptococci, methicillin-resistant Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, Porphyromonas gingivalis, and Candida albicans before, immediately after, 1 h, and 3 h after oral care were estimated based on real-time polymerase chain reaction data.

Results

After irrigation of the oral cavity, the number of bacteria decreased, but increased again at 1 h after oral care in the control group; however, in the intervention group, the concentration of bacteria was significantly lower than that in the control group at 1 hour (p = 0.009), 2 h (p = 0.001), and 3 h (p = 0.001) after oral care. The growth of all bacterial species tested was inhibited in the intervention group at 3 h after oral care, suggesting that povidone iodine did not disturb the balance of the oral microbiota.

Conclusions

Topical application of povidone iodine after cleaning and irrigation of the oral cavity inhibited bacterial growth in the oropharyngeal fluid of patients on mechanical ventilation while not disrupting the balance of the oral microbiota.

Trial registration

University Hospitals Medical Information Network Clinical Trials Registry (UMIN-CTR), UMIN000028307. Registered 1 September 2017.

Diagnosis and management of catheter-related bloodstream infections in patients on home parenteral nutrition

Catheter-related bloodstream infections (CRBSIs) commonly arise from a parenteral nutrition catheter hub. A target for a Nutrition Support Team is to have a CRBSI rate of less than 1 per 1000. The diagnosis of CRBSI is suspected clinically by a temperature shortly after setting up a feed, general malaise or raised blood inflammatory markers. It is confirmed by qualitative and quantitative blood cultures from the catheter and peripherally. Treatment of inpatients may involve central venous catheter removal and antibiotics for patients needing short-term parenteral nutrition, but catheter salvage is generally recommended for patients needing long-term parenteral nutrition, where appropriate.

Prevalence of and risk factors for intravenous catheter infection in hospitalized cattle, goats, and sheep

BACKGROUND

Intravenous catheter (IVC) use in hospitalized ruminants is a common procedure. Limited information is available describing complications associated with IVCs.

HYPOTHESES

Prevalence of IVC infections in hospitalized ruminants is >50%. Intravenous catheters maintained for >5 days are more likely to be infected than those maintained for <5 days. Intravenous catheters placed non-aseptically have a higher risk for infection than those placed aseptically.

ANIMALS

Thirty-four cattle, 39 goats, and 33 sheep were hospitalized in a university teaching hospital.

METHODS

Prospective observational study. The IVCs from cattle, goats, and sheep admitted for medical and surgical procedures were randomly selected and submitted for bacteriological culture and susceptibility testing.

RESULTS

Prevalence values (95% confidence interval) of infected catheters were 61.8 (45.5, 78.1), 51.3 (35.3, 66.7), and 42.4% (25.2, 58.8) in cattle, goats, and sheep, respectively. Coagulase-negative Staphylococcus spp was the most frequently isolated bacterium. Catheter type/placement technique was a significant (P = .03) predictor of IVC infection in goats but not in cattle (P = .65) and sheep (P = .47). Antibiotic use and reason for catheter placement were not significant predictors of IVC infection in all species. Catheters maintained for >4 days had a higher likelihood of being infected than those maintained for <4 days in all species.

CONCLUSIONS AND CLINICAL IMPORTANCE

Clinicians should consider replacing catheters maintained for >4 days to reduce IVC infection.

A prospective, multicenter case control study of risk factors for acquisition and mortality in Enterobacter species bacteremia

BACKGROUND

Enterobacter is among the main etiologies of hospital-acquired infections. This study aims to identify the risk factors of acquisition and attributable mortality of Enterobacter bacteremia.

METHODS

Observational, case-control study for risk factors and prospective cohort for outcomes of consecutive cases with Enterobacter bacteremia. This study was conducted in five hospitals in Spain over a three-year period. Matched controls were patients with negative blood cultures and same sex, age, and hospitalization area.

RESULTS

The study included 285 cases and 570 controls. E. cloacae was isolated in 198(68.8%) cases and E. aerogenes in 89(31.2%). Invasive procedures (hemodialysis, nasogastric tube, mechanical ventilation, surgical drainage tube) and previous antibiotics or corticosteroids were independently associated with Enterobacter bacteremia. Its attributable mortality was 7.8%(CI95%2.7-13.4%), being dissimilar according to a McCabe index: non-fatal=3.2%, ultimately fatal=12.9% and rapidly fatal=0.12%. Enterobacter bacteremia remained an independent risk factor for mortality among cases with severe sepsis or septic shock (OR 5.75 [CI95%2.57-12.87], p<0.001), with an attributable mortality of 40.3%(CI95%25.7-53.3). Empiric therapy or antibiotic resistances were not related to the outcome among patients with bacteremia.

CONCLUSIONS

Invasive procedures, previous antibiotics and corticosteroids predispose to acquire Enterobacter bacteremia. This entity increases mortality among fragile patients and those with severe infections. Antibiotic resistances did not affect the outcome.

Nitroglycerin-Citrate-Ethanol Catheter Lock Solution Is Highly Effective for In Vitro Eradication of Candida auris Biofilm

Candida auris poses emerging risks for causing severe central line-associated bloodstream infections. We tested in vitro the ability of antifungal lock solutions to rapidly eradicate C. auris biofilms. Liposomal amphotericin B, amphotericin B deoxycholate, fluconazole, voriconazole, micafungin, caspofungin, and anidulafungin failed to completely eradicate all 10 tested C. auris biofilms. Conversely, nitroglycerin-citrate-ethanol (NiCE) catheter lock solution completely eradicated all replicates for all of C. auris biofilms tested.

Antibiotic susceptibility patterns of Staphylococcus aureus strains isolated at the Yaounde Central Hospital, Cameroon: a retro prospective study

Introduction

Staphylococcus aureus is an important pathogen responsible for hospital and community acquired infection(s). Emerging resistance to methicillin in this organism has left physicians with few therapeutic alternatives to treat infections caused by it. This study was aimed at determining the antibiotic susceptibility patterns of Staphylococcus aureus strains isolated at the Yaounde Central Hospital, Cameroon.

Methods

from January 2014 to November 2016, a total of 250 non repeated strains were isolated from various clinical specimens. Isolates and antibiotic susceptibility profiles were identified through standard microbiological techniques.

Results

methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) accounted respectively for 80% (201/205) and 20% (49/205) of the total strains isolated. MRSA strains displayed high resistance to cefoxitin (100%), cotrimoxazole (89%), vancomycin (79.7%), lincomycin (70.3%), tobramycin (72.5%), doxycycline (68.0%), kanamycin (69.7%) and erythromycin (55.7%). In contrast, a high susceptibility was observed with rifampicin (82.6%). KTG (42.3%) and constitutive MLSB (17.4%) were the most frequent phenotypes recorded.

Conclusion

our results show that the carriage of acquired MRSA infections predominates in this population. Despite the noticeable multiresistance of MRSA strains to antibiotics, rifampicin remains the drugs of choice for the therapy of acquired MRSA infections in this setting. In order to slow down antimicrobial resistance, surveillance studies for antimicrobial susceptibility remains essential to identify resistance and inform policy on resistance.

Risk factors of ventilator-associated pneumonia in elderly patients receiving mechanical ventilation

Purpose: The aim of this study was to verify the potential risk factors of ventilator-associated pneumonia (VAP) in elderly Chinese patients receiving mechanical ventilation (MV). The secondary aim of this study was to present logistical regression prediction models of VAP occurrence in elderly Chinese patients receiving MV. Methods: Patients (aged 80 years or above) receiving MV for ≥48 h were enrolled from the Chinese People's Liberation Army (PLA) General Hospital from January 2011 to December 2015. A chi-squared test and Mann-Whitney U-test were used to compare the data between participants with VAP and without VAP. Univariate logistic regression models were performed to explore the relationship between risk factors and VAP. Results: A total of 901 patients were included in the study, of which 156 were diagnosed as VAP (17.3%). The incidence density of VAP was 4.25/1,000 ventilator days. Logistic regression analysis showed that the independent risk factors for elderly patients with VAP were COPD (OR =1.526, P < 0.05), intensive care unit (ICU) admission (OR=1.947, P < 0.01), the MV methods (P < 0.023), the number of antibiotics administered (OR=4.947, P < 0.01), the number of central venous catheters (OR=1.809, P < 0.05), the duration of indwelling urinary catheter (OR=1.805, P < 0.01) and the use of corticosteroids prior to MV (OR=1.618, P < 0.05). Logistic regression prediction model of VAP occurrence in the Chinese elderly patients with mechanical ventilation:L o g i t   P = - 6 . 468 + 0 . 423 X 1 + 0 . 666 X 2 + 0 . 871 X 3 + - 0 . 501 X 5 + 0 . 122 X 6 + 0 . 593 X 7 + 0 . 590 X 8 + 1 . 599 X 9 . Conclusion: VAP occurrence is associated with a variety of controllable factors including the MV methods and the number of antibiotics administered. A model was established to predict VAP occurrence so that high-risk patients could be identified as early as possible.

Epidemiology of Infectious and Noninfectious Catheter Complications in Patients Receiving Home Parenteral Nutrition: A Systematic Review and Meta-Analysis

Patients receiving parenteral nutrition (PN) as their primary source of nutrition are at high risk for both infectious and noninfectious catheter complications (catheter-related infections, catheter occlusion, and venous thrombosis). The aim of this review was to synthesize and evaluate what is known about catheter complications and prevention strategies in the PN population. Three electronic databases (Medline, Embase, and CINAHL) were screened for studies published between January 2012 and February 2019 regarding infectious and noninfectious catheter complications in patients receiving PN. Rates of infectious and noninfectious catheter complications, prevalence of causative pathogens, potential risk factors, and prevention strategies via the use of antimicrobial lock therapy (ALT) were assessed. Fifty-three catheter complication studies and 12 ALT studies were included. Studies were grouped by definition of complication: catheter-related bloodstream infections (CRBSI) or central line-associated bloodstream infections (CLABSI). Random effects summary rates per 1000 catheter days were 0.85 CRBSI episodes (95% CI 0.27-2.64) and 1.65 CLABSI episodes (95% CI 1.09-2.48). Use of taurolidine or ethanol ALT was efficacious in reducing infectious catheter complications; however, several studies had concerns for adverse mechanical complications. Potential risk factors for catheter complications were highly varied and often contradictory between studies. The rates of catheter complications were higher among catheterized patients receiving PN compared with nationally reported rates of complications in all catheterized patients. Risk factors for catheter complications need to be better understood for targeted prophylactic use of ALT. Future studies are warranted; however, they should be conducted using more standardized definitions and criteria.

Ventilator-associated pneumonia and bloodstream infections in intensive care unit cancer patients: a retrospective 12-year study on 3388 prospectively monitored patients

Purpose

Some publications suggest high rates of healthcare-associated infections (HAIs) and of nosocomial pneumonia portending a poor prognosis in ICU cancer patients. A better understanding of the epidemiology of HAIs in these patients is needed.

Methods

A retrospective analysis of all the patients hospitalized for ≥ 48 h during a 12-year period in the 12-bed ICU of the Gustave Roussy hospital, monitored prospectively for ventilator-associated pneumonia (VAP) and bloodstream infection (BSI) and for use of medical devices.

Results

During 3388 first stays in the ICU, 198 cases of VAP and 103 primary, 213 secondary, and 77 catheter-related BSIs were recorded. The VAP rate was 24.5/1000 ventilator days (95% confidence interval [CI] 21.2–28.0); the catheter-related BSI rate was 2.3/1000 catheter days (95% CI 1.8–2.8). The cumulative incidence during the first 25 days of exposure was 58.8% (95% CI 49.1–66.6%) for VAP, 8.9% (95% CI, 6.2–11.5%) for primary, 15.1% (95% CI 11.6–18.5%) for secondary and 5.0% (95% CI 3.2–6.8%) for catheter-related BSIs. VAP or BSIs were not associated with a higher risk of ICU mortality.

Conclusions

This is the first study to report HAI rates in a large cohort of critically ill cancer patients. Although both the incidence of VAP and the rate of BSI are higher than in general ICU populations, this does not impact patient outcomes. The occurrence of device-associated infections is essentially due to severe medical conditions in patients and to the characteristics of malignancy.

Electronic supplementary material

The online version of this article (10.1007/s00520-019-04800-6) contains supplementary material, which is available to authorized users.

In Vitro Comparison of Antibacterial and Antibiofilm Activities of Selected Fluoroquinolones against Pseudomonas aeruginosa and Methicillin-Resistant Staphylococcus aureus

An in vitro overview of the inhibitory effects of selected fluoroquinolones against planktonic and biofilm cells of the methicillin-resistant Staphylococcus aureus (MRSA) strain American type culture collection (ATCC) 43300 and the Pseudomonas aeruginosa strain ATCC 27853 was carried out. Biofilm cells of both strains were less susceptible to the selected antibiotics than their planktonic counterparts. In addition, certain antibiotics were more effective against biofilm cells, while others performed better on the planktonic cells. Against P. aeruginosa, ciprofloxacin was the most potent on both planktonic and biofilm cells, whereas ofloxacin was the least potent on both biofilm and planktonic cells. Moxifloxacin and gatifloxacin were the most potent against both planktonic and biofilm MRSA bacteria, however, not in the same order of activity. Norfloxacin was the least active when tested against both planktonic and biofilm cells. The results of this work are expected to provide insight into the efficacy of various fluoroquinolones against MRSA and Pseudomonas aeruginosa biofilms. This study could form the basis for future clinical studies that could recommend special guidelines for the management of infections that are likely to involve bacteria in their biofilm state.

Association of preoperative anxiety and depression symptoms with postoperative complications of cardiac surgeries

OBJECTIVE

to investigate the associations of preoperative anxiety and depression symptoms with postoperative complications and with sociodemographic and clinical characteristics of patients submitted to the first coronary artery bypass graft.

METHOD

observational, analytical and longitudinal study. A consecutive non-probabilistic sample consisted of patients submitted to coronary artery bypass graft. To evaluate the symptoms, the Hospital Anxiety and Depression Scale was used. tracheal intubation for more than 48 hours, hemodynamic instability, sensorineural deficit, agitation, hyperglycemia, infection, nausea, vomiting, pain and death were classified as complications. The Mann-Whitney and Spearman Correlation tests were used, with a significance level of 0.05.

RESULTS

a total of 75 patients participated. The group that presented hemodynamic instability in the postoperative period had a greater median for the anxiety symptoms (p = 0.012), as well as the women (p = 0.028). The median of the depression symptoms was higher in the group presenting nausea (p = 0.002), agitation (p <0.001), tracheal intubation for more than 48 hours (p = 0.018) and sensorineural deficit (p = 0.016).

CONCLUSION

there was association of the symptoms of preoperative anxiety with hemodynamic instability in the postoperative period and with the female gender, as well as association of depression symptoms with the following complications: nausea, agitation, time of intubation in the postoperative period and sensorineural deficit.

Clinico-microbiological profile of healthcare associated pneumonia in critically ill patients at level-I trauma centre of India

INTRODUCTION

Device-associated infections constitute the majority of health-care infections in Intensive Care Units (ICUs). Trauma patients are more prone to acquire such infections; ventilator-associated pneumonia (VAP) being the most common Health care associated infections (HAI) in ICU has serious implications such as increased morbidity, prolonged hospital stay, and mortality. This study aims to compare the clinicomicrobiological profile of VAP and non-VAP trauma patients at Level I trauma center.

MATERIALS AND METHODS

A 4-year retrospective study of prospectively maintained database was conducted at Level 1 trauma center from January 2013 to December 2016. The patients were classified into two groups named VAP and non-VAP patients. VAP patients were defined according to the criteria of the Centers for Disease Control and Prevention. The data were compiled and analyzed. Statistical data were analyzed using SPSS version 21 software.

RESULTS

During the study period, 134 (13%) cases of VAP and 909 (87%) non-VAP cases were observed in our study. The total number of ventilator days for VAP patients was 5128 days, which ranged from 2 to 82 days (median 42 days). The length of hospital stay in non-VAP category ranged from 1 to 390 days (median 195.5 days). Inhospital mortality was observed in 62 (46%) patients with VAP. Three hundred and eighteen (35%) non-VAP patients had also had a fatal outcome. Gram-negative organisms, most commonly Acinetobacter spp. (13, 21%), were reported in the fatal VAP patients.

CONCLUSION AND DISCUSSION

Higher rate of mortality was observed in patients with VAP in comparison to non-VAP patients, both being on mechanical ventilation. Early recognition of VAP, implementation of proper VAP preventive bundle strategies, and stringent infection control practices are essential mandates to prevent VAP.

Multidrug-resistant bacterial isolates from patients suspected of nosocomial infections at the University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia

Objectives

As the hospital environment favors the circulation of drug resistant bacteria, continuous surveillance of antibiotic resistant patterns is an important approach for a better patient management. This study is therefore, aimed to assess multidrug resistant bacterial isolates from patients suspected of nosocomial infections at the University of Gondar Comprehensive Specialized Hospital, Gondar, Ethiopia.

Results

Of the 260 patients, 173 (66.5%) of them were culture positive. Among culture positive patients a total of 216 bacterial isolates were recovered, of which the most common species were S. aureus 77 (35.6%), followed by E. coli 33 (15.3%) and Klebsiella spp 29 (13.4%). Of the S. aureus isolates, 67.5% were cefoxitin (methicillin) resistant. Citrobacter spp (100%), Klebsiella spp (79.3%) and E. coli (75.3%) were the leading MDR Gram-negative isolates. The overall MDR resistant rate was 152 (70.4%).

Chloramphenicol-borate/boronate complex for controlling infections by chloramphenicol-resistant bacteria

Increasing bacterial resistance to antibiotics is a pressing problem worldwide, with many health organisations prioritizing this issue. Whilst there is a desperate need for new effective antimicrobials, it is also important to understand the mechanisms and epidemiology of the resistant pathogens currently present in the community. Chloramphenicol is one such well known antibiotic which had lost its efficacy due to bacterial resistance. In this paper, we report the design, synthesis, and bio-studies of novel chloramphenicol-borate/boronate derivatives which showed the ability to control the infections caused by chloramphenicol-resistant bacteria. Activity profiling against P. aeruginosa strain EXR1 with catB gene indicated the inability of acetyl transferase to acetylate the chloramphenicol-borate/boronate complex, unlike chloramphenicol. Results obtained from the antimicrobial assays were further rationalized by molecular docking studies. The latter revealed that the probable reason for the enhanced antibacterial activity may be attributed to the change in the binding site of chloramphenicol-borate/boronate with chloramphenicol acetyl transferase (CAT) with respect to chloramphenicol itself. Hemolytic and genotoxic studies established the reduced toxicity of these synthetic derivatives with respect to chloramphenicol.

We report the design, synthesis, and bio-studies of novel chloramphenicol-borate/boronate derivatives which could control the infections caused by chloramphenicol-resistant bacteria.

Comparative Efficacies of Antimicrobial Catheter Lock Solutions for Fungal Biofilm Eradication in an in Vitro Model of Catheter-Related Fungemia

Fungal catheter-related bloodstream infections (CRBSIs)-primarily due to Candida species-account for over 12% of all CRBSIs, and have been progressively increasing in prevalence. They present significant health and economic burdens, and high mortality rates. Antimicrobial catheter lock solutions are an important prophylactic option for preventing fungal CRBSIs. In this study, we compared the effectiveness of two FDA-approved catheter lock solutions (heparin and saline) and three experimental antimicrobial catheter lock solutions-30% citrate, taurolidine-citrate-heparin (TCH), and nitroglycerin-citrate-ethanol (NiCE)-in an in vitro model of catheters colonized by fungi. The fungi tested were five different strains of Candida clinical isolates from cancer patients who contracted CRBSIs. Time-to-biofilm-eradication was assessed in the model with 15, 30, and 60 min exposures to the lock solutions. Only the NiCE lock solution was able to fully eradicate all fungal biofilms within 60 min. Neither 30% citrate nor TCH was able to fully eradicate any of the Candida biofilms in this time frame. The NiCE lock solution was significantly superior to TCH in eradicating biofilms of five different Candida species (p = 0.002 for all).

Risk factors for Candida parapsilosis bloodstream infection in a neonatal intensive care unit: a case-control study

Background

Candida parapsilosis is increasingly responsible for invasive candidiasis in neonates. This study investigates phenotypic and genotypic features of C. parapsilosis microbial isolates and underlying clinical conditions associated with acquisition of C. parapsilosis in a neonatal intensive care unit (NICU) in Italy.

Methods

Identification of C. parapsilosis was performed by VITEK® 2 and MALDI TOF and confirmed by analysis of internal transcribed spacer ribosomal DNA sequences. Genotyping was performed by PCR fingerprinting. Antifungal susceptibility of strains was evaluated by microdilution. A case-control study was designed to identify risk factors for C. parapsilosis bloodstream infection.

Results

During the study period (April 2009- April 2012), C. parapsilosis was responsible for 6 umbilical catheter and 11 central catheter-associated bloodstream infection in 17 neonates in the NICU. Molecular typing identified identical fingerprinting profile in all C. parapsilosis isolates from neonates. Fifteen of 17 C. parapsilosis isolates were susceptible to all antifungal drugs, two isolates were resistant to fluconazole and intermediate susceptible to itraconazole. Low birthweight, gestational age and time to exposure to assisted ventilation were risk factors for C. parapsilosis infection in neonates in the NICU at univariate and multivariate analysis.

Conclusion

C. parapsilosis bloodstream infections in the NICU were caused by a single epidemic clone. Low birthweight, gestational age and time to exposure to invasive devices, with predominance of assisted ventilation, were the clinical conditions associated with C. parapsilosis bloodstream infection in the NICU.

Electronic supplementary material

The online version of this article (doi:10.1186/s13052-017-0332-5) contains supplementary material, which is available to authorized users.

Protease-Sensitive Inhibitory Activity of Cell-free Supernatant of Lactobacillus crispatus 156 Synergizes with Ciprofloxacin, Moxifloxacin and Streptomycin Against Pseudomonas aeruginosa: An In Vitro Study

Ciprofloxacin and streptomycin are frequently prescribed for the treatment of medical conditions originating due to infection by Pseudomonas aeruginosa. However, fluoroquinolone administration has been linked to the outgrowth of Clostridium difficile pathogen, especially in immunocompromised patients. Secondly, frequent administration of antibiotics may lead to development of resistance in the pathogens. Thus, there is a need to explore innovative adjunct therapies to lower the therapeutic doses of the antibiotics. Herein, we evaluated the synergism, if any, between conventional antibiotics and the cell-free supernatant (CFS) of vaginal Lactobacillus crispatus 156 against P. aeruginosa MTCC 741. L. crispatus 156 was isolated from the human vaginal tract, and its CFS had broad-spectrum antimicrobial activity against various Gram-positive and Gram-negative pathogens, including P. aeruginosa. The inhibitory substance present in the CFS completely lost its activity after treatment with proteinases and was resistant to temperatures up to 80 °C and pH ranging from 2 to 6. The cumulative production of the inhibitory substance in CFS was studied, and it showed that the secretion of the inhibitory substance was initiated in middle log phase of growth and peaked in late log phase. Further, CFS synergized the activities of ciprofloxacin, moxifloxacin, and streptomycin as evaluated in terms of checkerboard titrations. It lowered the minimum inhibitory concentration (MIC) of ciprofloxacin by almost 30 times and MIC of both moxifloxacin and streptomycin by 8 times. Interestingly, pepsin treatment of CFS caused the complete abrogation of its synergistic effect with all the three antibiotics. Thus, from the study, it can be concluded that probiotic-based alternative therapeutic regimen can be designed for the treatment of P. aeruginosa infections.

Ventilator-Associated Pneumonia: A Review

Ventilator-associated pneumonia is the most frequent intensive care unit (ICU)-related infection in patients requiring mechanical ventilation. In contrast to other ICU-related infections, which have a low mortality rate, the mortality rate for ventilator-associated pneumonia ranges from 20% to 50%. These clinically significant infections prolong duration of mechanical ventilation and ICU length of stay, underscoring the financial burden these infections impose on the health care system. The causes of ventilator-associated pneumonia are varied and differ across different patient populations and different types of ICUs. This varied presentation underscores the need for the intensivist treating the patient with ventilator-associated pneumonia to have a clear knowledge of the ambient microbiologic flora in their ICU. Prevention of this disease process is of paramount importance and requires a multifaceted approach. Once a diagnosis of ventilator-associated pneumonia is suspected, early broad-spectrum antibiotic administration decreases morbidity and mortality and should be based on knowledge of the sensitivities of common infecting organisms in the ICU. De-escalation of therapy, once final culture results are available, is necessary to minimize development of resistant pathogens. Duration of therapy should be based on the patient’s clinical response, and every effort should be made to minimize duration of therapy, thus further minimizing the risk of resistance.

Risk Factors and Outcomes Associated With Non–Enterococcus faecalis, Non–Enterococcus faeciumEnterococcal Bacteremia

Objectives.

To compare risk factors, clinical features, and outcomes in patients withEnterococcus avium,Enterococcus casseliflavus,Enterococcus durans,Enterococcus gallinarum, andEnterococcus mundtiibacteremia (cases) with those in patients withEnterococcus faecalisbacteremia (controls).

Design.

A retrospective case-control study.

Setting.

A 725-bed, university-affiliated, academic medical center.

Patients.

The clinical microbiology database at Northwestern Memorial Hospital from January 1994 to May 2003 was searched to identify cases; each case was matched to one control on the basis of date of admission.

Results.

Thirty-three cases were identified and matched with 33 controls. The mean duration of hospital stay was longer (29.7 vs 17.2 days;P= .03) and the mean time to acquisition of bacteremia was greater (16.5 vs 6.3 days;P= .003) for cases than controls. Cases were more likely to have underlying hematologic malignancies (P< .001), to have been treated with corticosteroids (P= .02), and to be neutropenic (P= .003). Controls were more likely to have an indwelling bladder catheter (P= .01), and cases were more likely to have the gastrointestinal tract as a source of infection (P= .007) and to have concurrent cholangitis (P= .002). There were no differences in severity of illness or in mortality rates.

Conclusions.

Compared with patients withE. faecalisbacteremia, patients with non-E. faecalis, non-Enterococcus faeciumenterococcal bacteremia were more likely to have a hematologic malignancy, prior treatment with corticosteroids, neutropenia, and cholangitis; longer duration of hospital stay was also identified as a clinical feature. However, non-E. faecalis, non-E. faeciumspecies are not associated with any differences in mortality.

Modeling Transmission of Methicillin-ResistantStaphylococcus AureusAmong Patients Admitted to a Hospital

Objective:

To determine the impact of the screening test, nursing workload, handwashing rates, and dependence of handwashing on risk level of patient visit on methicillin-resistantStaphylococcus aureus(MRSA) transmission among hospitalized patients.

Setting:

General medical ward.

Methods:

Monte Carlo simulation was used to model MRSA transmission (median rate per 1,000 patient-days). Visits by healthcare workers (HCWs) to patients were simulated, and MRSA was assumed to be transmitted among patients via HCWs.

Results:

The transmission rate was reduced from 0.89 to 0.56 by the combination of increasing the sensitivity of the screening test from 80% to 99% and being able to report results in 1 day instead of 4 days. Reducing the patient-to-nurse ratio from 4.3 in the day and 6.8 at night to 3.8 and 5.7, respectively, reduced the number of nosocomial infections from 0.89 to 0.85; reducing the ratio to 1 and 1, respectively, further reduced the number of nosocomial infections to 0.32. Increases in handwashing rates by 0%, 10%, and 20% for high-risk visits yielded reductions in nosocomial infections similar to those yielded by increases in handwashing rates for all visits (0.89, 0.36, and 0.24, respectively). Screening all patients for MRSA at admission reduced the transmission rate to 0.81 per 1,000 patient-days from 1.37 if no patients were screened.

Conclusion:

Within the ranges of parameters studied, the most effective strategies for reducing the rate of MRSA transmission were increasing the handwashing rates for visits involving contact with skin or bodily fluid and screening patients for MRSA at admission. (Infect Control Hosp Epidemiol 2005;26:607- 615)

Dispersal ofStaphylococcus aureusInto the Air Associated With a Rhinovirus Infection

Objective:

To determine whether healthy adult nasal carriers ofStaphylococcus aureuscan disperseS. aureusinto the air after rhinovirus infection.

Design:

We investigated the “cloud” phenomenon among adult nasal carriers ofS. aureusexperimentally infected with a rhinovirus. Eleven volunteers were studied for 16 days in an airtight chamber wearing street clothes, sterile garb, or sterile garb plus surgical mask; rhinovirus inoculation occurred on day 2. Daily quantitative air, nasal, and skin cultures forS. aureus; cold symptom assessment; and nasal rhinovirus cultures were performed.

Setting:

Wake Forest University School of Medicine, Winston-Salem, North Carolina.

Participants:

Wake Forest University undergraduate or graduate students who had persistent nasal carriage ofS. aureusfor 4 or 8 weeks.

Results:

After rhinovirus inoculation, dispersal ofS. aureusinto the air increased 2-fold with peak increases up to 34-fold. Independent predictors ofS. aureusdispersal included the time period after rhinovirus infection and wearing street clothes (P< .05). Wearing barrier garb but not a mask decreased dispersal ofS. aureusinto the air (P< .05).

Conclusion:

Virus-induced dispersal ofS. aureusinto the air may have an important role in the transmission ofS. aureusand other bacteria.

The effect of tooth brushing, irrigation, and topical tetracycline administration on the reduction of oral bacteria in mechanically ventilated patients: a preliminary study

Background

One of the main causes of ventilator-associated pneumonia (VAP) is thought to be aspiration of oropharyngeal fluid containing pathogenic microorganisms. The aim of this study was to examine the effects of various oral care methods on the reduction of oral bacteria during intubation.

Methods

First, the effect of mechanical oral cleaning was investigated. The bacterial count on the tongue and in the oropharyngeal fluid was measured after tooth brushing, irrigation, and three hours after irrigation in mechanically ventilated patients at the intensive care unit (ICU).

Next, the efficacy of topical administration of tetracycline and povidone iodine on the inhibition of bacterial growth on the tongue and in the oropharyngeal fluid was examined in oral cancer patients during neck dissection.

Results

The number of bacteria in the oropharyngeal fluid was approximately 10⁵–10⁶ cfu/mL before surgery, but increased to 10⁸ cfu/mL after intubation. Oral care with tooth brushing and mucosal cleaning did not reduce oral bacteria, while irrigation of the oral cavity and oropharynx significantly decreased it to a level of 10⁵ cfu/mL (p < 0.001). However, oral bacteria increased again to almost 10⁸ cfu/mL within three hours of irrigation.

Oral bacteria did not decrease by topical povidone iodine application. In contrast, 30 min after topical administration of tetracycline, the number of oral bacteria decreased to 10⁵ cfu/mL, and remained under 10⁶ cfu/mL throughout the entire experimental period of 150 min.

Conclusions

While the present studies are only preliminary, these results indicate that irrigation of the oral cavity and oropharynx followed by topical antibiotic administration may reduce oral bacteria in mechanically ventilated patients.

Trial registration

UMIN000018318, 1 August 2015.

Antibiotic Resistance Profiles and Genetic Similarities Within a New Generation of Carbapenem-Resistant Acinetobacter calcoaceticus-A. baumannii Complex Resistotypes in Bosnia and Herzegovina

Acinetobacter calcoaceticus-A. baumannii complex (ACB complex) is a nosocomial pathogen. Due to its high ability to develop antibiotic resistance, it has become a problematic challenge in the modern healthcare system. The molecular and genetic mechanisms of gaining multidrug resistance in ACB complex are well known. This study focuses on providing an overview of the antibiotic resistance profiles, genetic similarities and resistotypes, and general characteristics of carbapenem-resistant ACB complex (CRACB) in Bosnia and Herzegovina (BiH). In light of the data collected in this study, together with the already known information concerning antibiotic resistance of ACB complex, we intend to further elucidate the antibiotic therapy for CRACB strain resistotypes in BiH.

Genome-Wide Association Study of Staphylococcus aureus Carriage in a Community-Based Sample of Mexican-Americans in Starr County, Texas

Staphylococcus aureus is the number one cause of hospital-acquired infections. Understanding host pathogen interactions is paramount to the development of more effective treatment and prevention strategies. Therefore, whole exome sequence and chip-based genotype data were used to conduct rare variant and genome-wide association analyses in a Mexican-American cohort from Starr County, Texas to identify genes and variants associated with S. aureus nasal carriage. Unlike most studies of S. aureus that are based on hospitalized populations, this study used a representative community sample. Two nasal swabs were collected from participants (n = 858) 11–17 days apart between October 2009 and December 2013, screened for the presence of S. aureus, and then classified as either persistent, intermittent, or non-carriers. The chip-based and exome sequence-based single variant association analyses identified 1 genome-wide significant region (KAT2B) for intermittent and 11 regions suggestively associated with persistent or intermittent S. aureus carriage. We also report top findings from gene-based burden analyses of rare functional variation. Notably, we observed marked differences between signals associated with persistent and intermittent carriage. In single variant analyses of persistent carriage, 7 of 9 genes in suggestively associated regions and all 5 top gene-based findings are associated with cell growth or tight junction integrity or are structural constituents of the cytoskeleton, suggesting that variation in genes associated with persistent carriage impact cellular integrity and morphology.

Insights on virulence from the complete genome of Staphylococcus capitis

Staphylococcus capitis is an opportunistic pathogen of the coagulase negative staphylococci (CoNS). Functional genomic studies of S. capitis have thus far been limited by a lack of available complete genome sequences. Here, we determined the closed S. capitis genome and methylome using Single Molecule Real Time (SMRT) sequencing. The strain, AYP1020, harbors a single circular chromosome of 2.44 Mb encoding 2304 predicted proteins, which is the smallest of all complete staphylococcal genomes sequenced to date. AYP1020 harbors two large mobile genetic elements; a plasmid designated pAYP1020 (59.6 Kb) and a prophage, ΦAYP1020 (48.5 Kb). Methylome analysis identified significant adenine methylation across the genome involving two distinct methylation motifs (1972 putative 6-methyladenine (m6A) residues identified). Putative adenine methyltransferases were also identified. Comparative analysis of AYP1020 and the closely related CoNS, S. epidermidis RP62a, revealed a host of virulence factors that likely contribute to S. capitis pathogenicity, most notably genes important for biofilm formation and a suite of phenol soluble modulins (PSMs); the expression/production of these factors were corroborated by functional assays. The complete S. capitis genome will aid future studies on the evolution and pathogenesis of the coagulase negative staphylococci.