Emerging gram-positive bacterial infections

Six-year multicenter study on short-term peripheral venous catheters-related bloodstream infection rates in 204 intensive care units of 57 hospitals in 19 cities of India: International Nosocomial Infection Control Consortium (INICC) findings

BACKGROUND

Short-term peripheral venous catheters-related bloodstream infections (PVCR-BSIs) rates have not been systematically studied in developing countries, and data on their incidence by number of device-days are not available.

METHODS

Prospective, surveillance study on PVCR-BSI conducted from September 1, 2013 to May 31, 2019 in 204 intensive care units (ICUs), members of the International Nosocomial Infection Control Consortium (INICC), from 57 hospitals in 19 cities of India. We applied US INICC definition criteria and reported methods using the INICC Surveillance Online System.

RESULTS

We followed 7,513 ICU patients for 296,893 bed-days and 295,795 short term peripheral venous catheter (PVC)-days. We identified 863 PVCR-BSIs, amounting to a rate of 2.91/1,000 PVC-days. Mortality in patients with PVC but without PVCR-BSI was 4.14%, and 11.59% in patients with PVCR-BSI. The length of stay in patients with PVC but without PVCR-BSI was 4.13 days, and 5.9 days in patients with PVCR-BSI. The micro-organism profile showed 68% of gram negative bacteria: Escherichia coli (23%), Klebsiella spp (15%), Pseudomonas aeruginosa (5%), and others. The predominant gram-positive bacteria were Staphylococcus aureus (10%).

CONCLUSIONS

PVCR-BSI rates found in our ICUs were much higher than rates published from industrialized countries. Infection prevention programs must be implemented to reduce the incidence of PVCR-BSIs.

Six-year study on peripheral venous catheter-associated BSI rates in 262 ICUs in eight countries of South-East Asia: International Nosocomial Infection Control Consortium findings

BACKGROUND

Short-term peripheral venous catheter-associated bloodstream infection rates have not been systematically studied in Asian countries, and data on peripheral venous catheter-associated bloodstream infections incidence by number of short-term peripheral venous catheter days are not available.

METHODS

Prospective, surveillance study on peripheral venous catheter-associated bloodstream infections conducted from 1 September 2013 to 31 May 2019 in 262 intensive care units, members of the International Nosocomial Infection Control Consortium, from 78 hospitals in 32 cities of 8 countries in the South-East Asia Region: China, India, Malaysia, Mongolia, Nepal, Philippines, Thailand, and Vietnam. For this research, we applied definition and criteria of the CDC NHSN, methodology of the INICC, and software named INICC Surveillance Online System.

RESULTS

We followed 83,295 intensive care unit patients for 369,371 bed-days and 376,492 peripheral venous catheter-days. We identified 999 peripheral venous catheter-associated bloodstream infections, amounting to a rate of 2.65/1000 peripheral venous catheter-days. Mortality in patients with peripheral venous catheter but without peripheral venous catheter-associated bloodstream infections was 4.53% and 12.21% in patients with peripheral venous catheter-associated bloodstream infections. The mean length of stay in patients with peripheral venous catheter but without peripheral venous catheter-associated bloodstream infections was 4.40 days and 7.11 days in patients with peripheral venous catheter and peripheral venous catheter-associated bloodstream infections. The microorganism profile showed 67.1% were Gram-negative bacteria: Escherichia coli (22.9%), Klebsiella spp (10.7%), Pseudomonas aeruginosa (5.3%), Enterobacter spp. (4.5%), and others (23.7%). The predominant Gram-positive bacteria were Staphylococcus aureus (11.4%).

CONCLUSIONS

Infection prevention programs must be implemented to reduce the incidence of peripheral venous catheter-associated bloodstream infections.

Six-year multicenter study on short-term peripheral venous catheters-related bloodstream infection rates in 246 intensive units of 83 hospitals in 52 cities of 14 countries of Middle East: Bahrain, Egypt, Iran, Jordan, Kingdom of Saudi Arabia, Kuwait, Lebanon, Morocco, Pakistan, Palestine, Sudan, Tunisia, Turkey, and United Arab Emirates-International Nosocomial Infection Control Consortium (INICC) findings

BACKGROUND

Short-term peripheral venous catheters-related bloodstream infections (PVCR-BSIs) rates have not been systematically studied, and data on their incidence by number of device-days is not available.

METHODS

Prospective, surveillance study on PVCR-BSI conducted from September 1st, 2013 to 31st Mays, 2019 in 246 intensive care units (ICUs), members of the International Nosocomial Infection Control Consortium (INICC), from 83 hospitals in 52 cities of 14 countries in the Middle East (Bahrain, Egypt, Iran, Jordan, Kingdom of Saudi Arabia, Kuwait, Lebanon, Morocco, Pakistan, Palestine, Sudan, Tunisia, Turkey, and United Arab Emirates). We applied U.S.

RESULTS

We followed 31,083 ICU patients for 189,834 bed-days and 202,375 short term peripheral venous catheter (PVC)-days. We identified 470 PVCR-BSIs, amounting to a rate of 2.32/1000 PVC-days. Mortality in patients with PVC but without PVCR-BSI was 10.38%, and 29.36% in patients with PVC and PVCR-BSI. The mean length of stay in patients with PVC but without PVCR-BSI was 5.94 days, and 16.84 days in patients with PVC and PVCR-BSI. The microorganism profile showed 55.2 % of gram-positive bacteria, with Coagulase-negative Staphylococci (31%) and Staphylococcus aureus (14%) being the predominant ones. Gram-negative bacteria accounted for 39% of cases, and included: Escherichia coli (7%), Klebsiella pneumoniae (8%), Pseudomonas aeruginosa (5%), Enterobacter spp. (3%), and others (29.9%), such as Serratia marcescens.

CONCLUSIONS

PVCR-BSI rates found in our ICUs were much higher than rates published from USA, Australia, and Italy. Infection prevention programs must be implemented to reduce the incidence of PVCR-BSIs.

Six-year multicenter study on short-term peripheral venous catheters-related bloodstream infection rates in 727 intensive care units of 268 hospitals in 141 cities of 42 countries of Africa, the Americas, Eastern Mediterranean, Europe, South East Asia, and Western Pacific Regions: International Nosocomial Infection Control Consortium (INICC) findings

BACKGROUND

Short-term peripheral venous catheter-related bloodstream infection (PVCR-BSI) rates have not been systematically studied in resource-limited countries, and data on their incidence by number of device days are not available.

METHODS

Prospective, surveillance study on PVCR-BSI conducted from September 1, 2013, to May 31, 2019, in 727 intensive care units (ICUs), by members of the International Nosocomial Infection Control Consortium (INICC), from 268 hospitals in 141 cities of 42 countries of Africa, the Americas, Eastern Mediterranean, Europe, South East Asia, and Western Pacific regions. For this research, we applied definition and criteria of the CDC NHSN, methodology of the INICC, and software named INICC Surveillance Online System.

RESULTS

We followed 149,609 ICU patients for 731,135 bed days and 743,508 short-term peripheral venous catheter (PVC) days. We identified 1,789 PVCR-BSIs for an overall rate of 2.41 per 1,000 PVC days. Mortality in patients with PVC but without PVCR-BSI was 6.67%, and mortality was 18% in patients with PVC and PVCR-BSI. The length of stay of patients with PVC but without PVCR-BSI was 4.83 days, and the length of stay was 9.85 days in patients with PVC and PVCR-BSI. Among these infections, the microorganism profile showed 58% gram-negative bacteria: Escherichia coli (16%), Klebsiella spp (11%), Pseudomonas aeruginosa (6%), Enterobacter spp (4%), and others (20%) including Serratia marcescens. Staphylococcus aureus were the predominant gram-positive bacteria (12%).

CONCLUSIONS

PVCR-BSI rates in INICC ICUs were much higher than rates published from industrialized countries. Infection prevention programs must be implemented to reduce the incidence of PVCR-BSIs in resource-limited countries.

Artificial opsonin enhances bacterial phagocytosis, oxidative burst and chemokine production by human neutrophils

Here, we describe the application of an 'artificial opsonin' to stimulate the innate immune response against Gram-positive bacteria. The artificial opsonin comprises a poly(L-lysine)-graft-poly(ethylene glycol) backbone displaying multiple copies of vancomycin and human IgG-Fc. The vancomycin targets bacteria by recognizing d-Ala-d-Ala-terminated peptides present in the bacterial cell wall. The human IgG-Fc antibody fragments serve as phagocyte recognition moieties that recognize the Fcγ cell surface receptors expressed by professional human phagocytes. Staphylococcus epidermidis RP62A, a biofilm-forming, methicillin-resistant strain, was utilized to investigate the effects of opsonization on phagocytosis, oxidative burst and IL-8 chemokine production by human neutrophils. Results show that opsonization of S. epidermidis RP62A with the artificial opsonin resulted in an ∼2-fold increase in neutrophil phagocytosis. Analysis of the cell supernatant found a 2- to 3-fold increase in neutrophil IL-8 secretion. The neutrophil oxidative burst was investigated using the oxidation-sensitive fluorophore dihydrorhodamine-123. Bacterial opsonization resulted in a 20% increase in fluorescence intensity, indicating a significant increase in the production of reactive oxygen species by the neutrophils. These studies suggest that artificial opsonins may be a novel immunostimulation therapeutic strategy to control infections caused by Gram-positive bacteria, particularly those that are known to be immune evasive and/or antibiotic resistant.

Role of bacteriophage-encoded exotoxins in the evolution of bacterial pathogens

Recent advances in metagenomics research have generated a bounty of information that provides insight into the dynamic genetic exchange occurring between bacteriophage (phage) and their bacterial hosts. Metagenomic studies of the microbiomes from a variety of environments have shown that many of the genes sequenced are of phage origin. Among these genes are phage-encoded exotoxin genes. When phage that carry these genes infect an appropriate bacterial host, the bacterium undergoes lysogenic conversion, converting the bacterium from an avirulent strain to a pathogen that can cause human disease. Transfer of the exotoxin genes between bacteria has been shown to occur in marine environments, animal and human intestines and sewage treatment plants. Surprisingly, phage that encode exotoxin genes are commonly found in environments that lack the cognate bacteria commonly associated with the specific toxin-mediated disease and have been found to be associated with alternative environmental bacterial hosts. These findings suggest that the exotoxin genes may play a beneficial role for the bacterial host in nature, and that this environmental reservoir of exotoxin genes may play a role in the evolution of new bacterial pathogens.

DNA sequence-based detection of group B Streptococcus directly from heart valve tissue in a patient with culture-negative endocarditis

A human case of culture-negative bacterial endocarditis is presented where conventional methods failed to determine a microbial aetiology. DNA sequencing performed directly on autopsy heart valve tissue revealed Streptococcus agalactiae (group B streptococcus). To our knowledge, this is the first report of DNA sequence-based detection of this organism directly from a heart valve.

Activity of Ceftibuten, Cefaclor, Azithromycin, Clarithromycin, Erythromycin and Telithromycin against Streptococcus pyogenes Clinical Isolates with Different Genotypes and Phenotypes

BACKGROUND

The growing number of macrolide-resistant strains of Streptococcus pyogenes represents an increasing worldwide problem. Macrolide resistance in S. pyogenes is mediated by several different genes, which determine different levels of resistance to macrolides, lincosamides and streptogramin B (MLS).

METHODS

This study compared the in vitro antimicrobial activity of azithromycin, clarithromycin, erythromycin, ceftibuten, cefaclor, and telithromycin against 287 strains of S. pyogenes by the broth microdilution method. All strains were characterized both phenotypically and genotypically for erythromycin resistance and most of them have been M-typed by means of PCR.

RESULTS

Ceftibuten and cefaclor showed the best antimicrobial activity, while MIC values for telithromycin were higher against constitutively MLS (cMLS)-resistant strains rather than against the other phenotypes.

CONCLUSION

Oral cephalosporins retain the best activity against S. pyogenes; showing good activity except for cMLS-resistant strains, telithromycin is a valid alternative to these antimicrobials.