Bloodstream infections with emphasis on Methicillin-resistant Staphylococcus aureus at the University of Gondar Comprehensive Specialized and Referral Hospital, Northwest Ethiopia

BACKGROUND

Staphylococcus aureus is the most common cause of bloodstream infections worldwide. Methicillin-resistant S. aureus is becoming more prevalent in bacteremia and septicemia cases. Thus, this study determined Staphylococcal bacteremia, Methicillin-resistant S. aureus infections, and antimicrobial susceptibility patterns of the isolates in Northwest Ethiopia.

METHODS AND MATERIALS

This retrospective cross-sectional study was conducted on all age bloodstream suspected patients at the University of Gondar Comprehensive Specialized and Referral Hospital from January 1th 2022 to June 30th, 2022. Data were collected using a designed data extraction tool. Blood samples were collected and inoculated to a sterile Tryptic Soya Broth. Bottles with bacterial growth were subcultured to blood agar, chocolate agar, MacConkey agar, and mannitol salt agar plates. Antimicrobial susceptibility testing was performed using the Kirby Bauer disc diffusion technique. The data were entered using Epi-info version 7 and exported to SPSS version 20 for analysis.

RESULTS

Among 1200 patients included in this study, 719 (59.9%) were males. The prevalence of S. aureus and Methicillin-resistant S. aureus was 26.2% (111/424) and 68.5% (76/111), respectively. The blood culture growth rate was 35.3% (424/1200). Among the isolated organisms, Gram-positive cocci account for 217 (51.2%) and Gram-negative bacilli were 173 (41.0%). Among S. aureus isolates, 63.7% were sensitive to gentamicin and 91.9% were resistant to penicillin. A high prevalence of bacteremia was found in males (60.1%) and ward locations at the neonatal intensive care unit (57.1%). Specifically, Methicillin-resistant S. aureus was highly prevalent in males, followed by pediatric age groups, and neonatal intensive care unit, which were 59.2%, 56.6%, and 44.7%, respectively.

CONCLUSION

In this study, the prevalence of Methicillin-resistant S. aureus bacteremia was high, indicating its spread in hospital settings such as intensive care units. This requires routine detection, molecular characterization of mecA gene, and improved infection prevention at the healthcare facility.

Dual Mode Analysis of Methicillin-Resistant Staphylococcus aureus by the CRISPR/Cas12a-Assisted Exonuclease-Mediated Signal Cycle

Methicillin-resistant Staphylococcus aureus (MRSA) is the main Gram-positive bacteria isolated from patients with ocular infections and remians a huge threat to public health. Therefore, sensitive and dual-mode analysis of MRSA is of great significance for evaluating MRSA infection. We depicted a clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a-based biosensor by integrating the exonuclease III (Exo III)-enhanced fluorescence and colorimetric signals for sensitive and dual-mode analysis of methicillin resistance in MRSA without needing nucleic acid amplification. In this method, Exo III-assisted signal recycling is triggered only when the target mecA gene activates the CRISPR/Cas12a complex, and the HP probes on the surface of magnetic nanoparticles are cleaved by the trans-cleavage activity of Cas12a. Taking the merits of the trans-cleavage activity of the CRISPR/Cas12a system and the Exo III-assisted signal recycling, this approach exhibits an exceptionally elevated detection threshold for the mecA gene. Besides MRSA detection, this accurate and sensitive sensor can be employed to assess additional biomarkers in disease diagnosis by simply changing the crRNA.

Epidemiology of Methicillin-resistant Staphylococcus aureus Colonization in Neonates within Neonatal Intensive Care Units: A Systematic Review and Meta-analysis

Introduction

Methicillin-resistant Staphylococcus aureus (MRSA) colonization in neonatal intensive care units (NICUs) is a significant global health concern, leading to severe infections, extended hospital stays, and substantial economic burdens on health-care systems. To develop effective infection control strategies, we need to fill existing gaps in our understanding of MRSA epidemiology in neonates. The aim of this systematic review is to provide an extensive analysis of the proportion of MRSA colonizations in NICUs.

Methods

We used a comprehensive search strategy across databases such as Medline, Embase, Global Health, Web of Science, and Global Index Medicus, in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Articles were independently reviewed and selected based on a variety of criteria, including the inclusion of neonates tested for MRSA colonization during NICU stay, and the reporting of community-acquired and hospital-acquired MRSA (CA-MRSA and HA-MRSA) incidence levels. Exclusion criteria included studies outside NICUs, those focused on specific MRSA outbreaks or clinical infections, review studies, and those lacking abstracts or full texts. Five authors independently extracted data, which was summarized and checked for quality. Statistical analysis included a random-effects model to compute pooled proportions, stratification by geographical location, evaluation of heterogeneity, and examination of publication bias.

Results

Our systematic review evaluated 62 studies out of an initial 536 records identified. The majority of the selected studies were conducted in high-income countries, primarily in the United States. From these studies, we estimated a cumulative incidence rate of 7.2% for MRSA colonization in NICUs. When the source of MRSA was considered, CA-MRSA incidence was 2.7%, while HA-MRSA incidence was notably higher at 11%. A subgroup analysis showed geographical differences in the cumulative incidence of MRSA colonization in NICUs, with Brazil having the lowest incidence and Taiwan the highest. The proportion of HA-MRSA colonization also varied significantly by country, with South Korea reporting higher incidence rates than the United States. However, the differences in CA-MRSA colonization rates between countries and WHO regions were not statistically significant.

Conclusions

Our systematic review found a cumulative incidence of 7.2% for MRSA colonization in NICUs, with HA-MRSA (11%) being more prevalent than CA-MRSA (2.7%). Regional variations were detected, with Taiwan exhibiting the highest cumulative incidence and South Korea having both the highest CA-MRSA and HA-MRSA. These findings underline the substantial public health impact of MRSA, especially in NICUs, necessitating context-specific prevention and control strategies. Future research should strive to address these regional disparities and aspire to attain a more globally representative understanding of MRSA colonization rates.

Exonuclease-III Assisted the Target Recycling Coupling with Hybridization Chain Reaction for Sensitive mecA Gene Analysis by Using PGM

In the field of neonatal infections nursing, methicillin-resistant Staphylococcus aureus (MRSA) is a major bacterial pathogen. Here, we present a portable biosensor for MRSA detection that is both highly sensitive and portable, owing to its implementation on the personal glucose meter (PGM) platform. The H probe was fixed on the magnetic bead for mecA gene analysis. A blunt 3' terminus appeared in the MBs-H probe when the mecA gene was present. Exonuclease-III (Exo-III) recognized the blunt terminus and cleaved it, freeing the mecA gene and so facilitating target recycling. In the meantime, the remaining H probe-initiated hybridization chain reaction (HCR) led to the desired signal amplification. Portable quantitative detection of mecA gene is possible because PGM can read the quantity of invertase tagged on HCR product. After optimizing several experimental parameters, such as the concentration of Exo-III and incubation time, the constructed sensor is extremely sensitive, with a detection limit of 2 CFU/mL. The results from this sensitive PGM-based sensor are in agreement with those obtained from plate counting methods, suggesting that it can be used to accurately assess the MRSA content in artificial clinical samples. In addition, the PGM sensor can significantly cut down on time spent compared to plate counting techniques. The manufactured sensor provides a promising option for accurate identification of pathogenic bacteria.

Severe cellulitis from methicillin-resistant Staphylococcus aureus (MRSA) in a couple of preterm twins: a case report

BACKGROUND

Preterms are at risk of systemic infections as the barrier function of their immature skin is insufficient. The long period of hospitalization and the huge number of invasive procedures represent a risk factor for complications. Among the nosocomial infections of the skin, methicillin-resistant Staphylococcus aureus (MRSA) is associated with significant morbidity and mortality. We report a clinical case of cellulitis and abscess in two preterm twins caused by MRSA in a tertiary level Neonatal Intensive Care Unit (NICU).

CASE PRESENTATION

Two preterm female babies developed cellulitis from MRSA within the first month of extrauterine life. The first one (BW 990 g) showed signs of clinical instability 4 days before the detection of a hyperaemic and painful mass on the thorax. The second one (BW 1240 g) showed signs of clinical instability contextually to the detection of an erythematous, oedematous and painful area in the right submandibular space. In both cases the diagnosis of cellulitis was confirmed by ultrasound. A broad spectrum, multidrug antimicrobial therapy was administered till complete resolution.

CONCLUSIONS

Due to the characteristic antibiotic resistance of MRSA and the potential complications of those infections in such delicate patients, basic prevention measures still represent the key to avoid the spreading of neonatal MRSA infections in NICUs, which include hand hygiene and strict precautions, as well as screening of patients for MRSA on admission and during hospital stay, routine prophylactic topical antibiotic of patients, enhanced environmental cleaning, cohorting and isolation of positive patients, barrier precautions, avoidance of ward crowding, and, in some units, surveillance, education and decolonization of healthcare workers and visiting parents.

Cumulative Antibiogram: A Rapid Method to Hinder Transmission of Resistant Bacteria to Oral Cavity of Newborn Babies

BACKGROUND

A rapid bacterial diagnostic is needed more and more in the treatment of patients, because of the emergence of antibiotic resistance. The cumulative antibiogram, an annual report that monitors antimicrobial resistance trends in health care facilities, may provide a profile of empirical therapy useful in diverse emergency situations, such as transmission of resistant bacteria to oral cavity of newborn babies. We aimed to draw a profile of antibiotic resistance encountered.

METHODS

We assessed the antibiotic resistance (ABR) profile in childbearing women and newborn babies in Ploiesti Obstetrics and Gynecology Hospital by the disk diffusion method characterizing the multidrug-resistant organisms after isolation and identification by phenotypic tests. Extended-spectrum β-lactamase (ESBL)-producing Enterobacterales (ESBL-E), Carbapenem-resistant Enterobacterales (CRE), vancomycin-resistant Enterococci (VRE), methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin resistant Group B Streptococcus (VR-GBS) were detected.

RESULTS

The prevalence of antibiotic resistance was 11.32% (53/468), while the prevalence of the ESBL-E, MRSA, VRE and VR-GBS strains was 8.34% (39/468). Within the bacteria isolated from fifty-three childbearing women, the prevalence of ESBL-E, MRSA, VRE and VR-GBS was 22.64% (12/53), 32.08% (17/53), 11.32% (6/53) and 7.55% (4/53). In the whole studied group, the prevalence was 2.56% (12/468), 3.63% (17/468), 1.28% (6/468) and 0.86% (4/468). Resistant bacteria were detected at birth in the oral cavity of the newborn babies in all cases. Maternal and neonatal isolates shared similar characteristics.

CONCLUSIONS

Cumulative antibiogram is useful in case of empiric treatment needed in diverse emergencies, such as transmission of resistant bacteria to oral cavity of newborn babies.

Epidemiology and infection control of Methicillin-resistant Staphylococcus aureus in a German tertiary neonatal intensive and intermediate care unit: A retrospective study (2013-2020)

In preterm and term infants who require intermediate or intensive care Methicillin-resistant Staphylococcus aureus (MRSA) infection can lead to significant morbidity. In this study MRSA colonization and infection were assessed in a mixed tertiary neonatal intensive and intermediate care unit in Germany over an 8-year period (2013-2020). We investigated patient-related factors, associated with nosocomial MRSA acquisition, and we discuss our infection control concept for MRSA. Of 3488 patients treated during the study period, 24 were MRSA positive patients, corresponding to 26 patient hospital stays. The incidence was 0.7 MRSA patients per 100 patients. The incidence density was 0.4 MRSA patient hospital stays per 1000 patient days. Twelve patients (50%) acquired MRSA in the hospital. One patient developed a hospital acquired MRSA bloodstream infection 9 days after birth (i.e., 0.03% of all patients on the ward during the study period). A total of 122 patients had to be screened to detect one MRSA positive patient. In a logistic regression model, the use of 3rd generation intravenous cephalosporin (cefotaxim) was associated with nosocomial MRSA acquisition compared with matched control patients who did not acquire MRSA. In sum, the burden of MRSA colonization and infection in the ward was low during the study period. A comprehensive infection control concept that included microbiologic colonization screening, prospective infection surveillance together with isolation and emphasis on basic hygiene measures is essential to handle MRSA in this specialized setting.

Risk Factors Associated with Methicillin Resistance in Hospitalized Newborn Infants with Staphylococcus aureus Infection

BACKGROUND

An increasing number of infections due to methicillin-resistant Staphylococcus aureus (S. aureus) have been reported worldwide. To explore the risk factors associated with methicillin-resistance among the neonates with confirmed S. aureus infections and thereby to help selection of appropriate empirical antibiotics.

METHODS

We compared a group of hospitalized neonates with culture confirmed methicillin-resistant S. aureus (MRSA) infections to a group with methicillin-sensitive S. aureus (MSSA) based on antimicrobial susceptibility reports. We used multivariable regression analysis to determine the risk factors for neonatal MRSA infections.

RESULTS

There was no difference in the ratio of local to systemic infections or mortality between the two groups. However, the total hospitalization days and the medical care expenses in the MRSA group were significantly increased when compared to that of the MSSA group. Prior use of antibiotics for more than 48 hours was an independent risk factor for neonatal acquisition of MRSA infections, while exclusive breast milk feeding was a protective factor against MRSA infections.

CONCLUSION

Restrictions on antibiotic abuse and promotion of breast milk feeding may protect newborns from MRSA infections. Prior history of antibiotic use and exclusive breast milk feeding may be important factors to consider in the selection of appropriate empirical antibiotics for use in neonates prior to the availability of the results of antimicrobial susceptibility testing.

Identifying a therapeutic target for vancomycin against staphylococci in young infants

OBJECTIVES

To determine the therapeutic target of vancomycin in young infants with staphylococcal infections.

METHODS

Retrospective data were collected for infants aged 0 to 90 days with CoNS or MRSA bacteraemia over a 4 year period at the Royal Children's Hospital Melbourne, Australia. Vancomycin broth microdilution MICs were determined. A published pharmacokinetic model was externally validated using the study dataset and a time-to-event (TTE) pharmacodynamic model developed to link the AUC of vancomycin with the event being the first negative blood culture. Simulations were performed to determine the trough vancomycin concentration that correlates with a 90% PTA of the target AUC24.

RESULTS

Thirty infants, 28 with CoNS and 2 with MRSA bacteraemia, who had 165 vancomycin concentrations determined were included. The vancomycin broth microdilution MIC was determined for 24 CoNS and 1 MRSA isolate, both with a median MIC of 1 mg/L (CoNS range = 0.5-4.0). An AUC0-24 target of ≥300 mg/L·h or AUC24-48 of ≥424 mg/L·h. increased the chance of bacteriological cure by 7.8- and 7.3-fold, respectively. However, AUC0-24 performed best in the pharmacokinetic-pharmacodynamic model. This correlates with 24 to 48 h trough concentrations of >15-18 mg/L and >10-15 mg/L for 6- and 12-hourly dosing, respectively, and can be used to guide vancomycin therapy in this population.

CONCLUSIONS

An AUC0-24 ≥300 mg/L·h or AUC24-48 ≥424 mg/L·h was associated with an increase in bacteriological cure in young infants with staphylococcal bloodstream infections.

Methicillin-resistant Staphylococcus aureus transmission and hospital-acquired bacteremia in a neonatal intensive care unit in Greece

BACKGROUND

Staphylococcus aureus is a common pathogen causing hospital acquired infections (HAIs) in neonates. In this study, the epidemiology of methicillin-resistant S. aureus (MRSA) colonization and infections in a 30-bed, level III university-affiliated neonatal intensive care unit (NICU) located in a children's hospital was retrospectively investigated for the period 2014-2018.

METHODS

Genes encoding Panton-Valentine Leukocidin (lukS/lukF-PV, PVL), toxic shock syndrome toxin (tst), exfoliative toxins (eta, etb), and the resistance genes mecA, mecC and fusB, were defined in 46 representative strains by PCRs. Relatedness of strains was assessed by MLST.

RESULTS

Of 1538 neonates, 77 (5%) had a positive culture for MRSA (23/77 were NICU-acquired and 54/77 imported cases). Four MRSA bacteremias occurred. Most isolates were multi-resistant. One major clone was identified, ST225, among 40 tested neonatal strains (23/40, 58%). Of these, 14/23 were imported from the same maternity hospital (MH). Another clone, ST217, was predominant (4/6) among health care workers (HCWs), found colonized. Four isolates classified as ST80 were PVL-positive. Additional four strains carried tst (10%), belonging to ST30 and ST225 (two strains each), and two etb. The implicated MH was notified for the problem, decolonization treatment was successfully performed in HCWs and neonates. Strengthening of infection control measures with emphasis on hand hygiene was applied.

CONCLUSIONS

Uncovering reservoirs for on-going MRSA transmission in NICUs has proved challenging. Well known nosocomial MRSA clones are being constantly introduced and transmitted via MHs and HCWs. Effective infection prevention and control requires constant vigilance.

Mother-to-Neonate Transmission of Antibiotic-Resistant Bacteria: A Cross-Sectional Study

We evaluated carriage rates of extended spectrum β-lactam-producing Enterobacterales (ESBL-E), Carbapeneme-resistant Enterobacterales (CRE), vancomycin-resistant Enterococci (VRE), and methicillin-resistant Staphylococcus aureus (MRSA) among pregnant women and determined the maternal-to-neonate transmission rates of these antibiotic-resistant bacteria (ARB). Pregnant women provided rectal and vaginal samples, proximal to delivery. Stool samples were collected from newborns within 48 h of birth. All samples were cultured on selective media for ARB identification. Clinical and demographic data were collected from the participants' medical files. We performed molecular and phenotypic characterization of the different resistance mechanisms, and determined the isolates' antibiotic susceptibility and biofilm-forming ability. The prevalence of ESBL-E, MRSA and VRE among pregnant women were 16%, 6% and 1%, respectively. The prevalence of ESBL-E and MRSA among neonates were 7.6% and 1.6%, respectively. Maternal-to-neonate transmission rates of ESBL-E and MRSA were 48% and 27.8%, respectively. Maternal and neonatal isolates shared similar characteristics. Maternal-to-neonate transmission of ARB plays an important role in bacterial colonization in newborns. Future studies should investigate the outcomes of the high ESBL-E transmission rate. The biofilm-forming ability of ARB was found to affect transmission. Additional factors should be investigated in order to understand the differences between transmitted and non-transmitted bacteria.

MRSA colonisation rates on a neonatal and paediatric intensive care unit

Methicillin-resistant Staphylococcus aureus (MRSA) colonisation is a challenge in healthcare institutions worldwide. In this retrospective nation-wide study, the rates of MRSA colonisation and infection from 2012 to 2015, on the only neonatal and paediatric intensive care unit (NPICU) in the country, were determined. Mean local rates were compared to rates of MRSA colonisation reported in units in North America, Asia and Europe between 2001 and 2010. The average rate of MRSA colonisation on admission to NPICU from 2012 to 2015 was 3.71% (95% confidence interval [CI] 2.17-5.25), while the mean rate of acquired colonisation was 14.60% (95% CI 6.16-23.04). Both were significantly higher than in units abroad: 1.9% and 4.1%, respectively (P = 0.04 and P < 0.001). There were no cases of invasive MRSA infection, while the mean rate of non-invasive infection was 0.77% (95% CI 0.54-1.01). Improved adherence to infection control measures and newer molecular diagnostic techniques are needed to further decrease the acquisition of MRSA.

A self-sterilizing fluorescent nanocomposite as versatile material with broad-spectrum antibiofilm features

Hematogenous spread of infections from colonized central intravenous catheters or central lines is a long-recognized problem with infection rates of 2 and 6.8 per 1000 days, respectively. Besides, removal of severe microbial colonization of implanted biomaterials is still a challenge and usually requires invasive operations. Hence, on demand self-sterilizing materials are required to avoid explant of colonized biomaterials and improve patient compliance. Moreover, photoluminescence is needed to make trackable biomaterials, which can be easily monitored upon implanting them in the body. Here, we propose the incorporation of near infrared (NIR) sensitive red-emitting carbon nanodot (CDs) into a polymeric matrix to give rise to innovative biomaterials with self-tracking and photothermal antimicrobial abilities. We obtain a material which can be processed to obtain medical devices using different techniques, among which, for instance, electrospinning. Herein, a proof-of-concept preparation of electrospun scaffolds is reported as it is highly desired in biomedical applications. Beside to confer imaging properties to the scaffold, that would allow an easy control over the in vivo positioning of implanted biomaterials as well as its degradation state and grade of integration with the surrounding native tissues, thanks to the capability to convert NIR light into local heat CDs can be exploited to exert broad-spectrum antimicrobial effect toward several pathogens. The rise in temperature can be easily modulated by controlling the irradiation time to achieve both an in vitro self-sterilization of the device and eventually in vivo destabilization of the microbial colonization. This innovative biomaterial could successfully inhibit biofilm formation and might be used as a powerful tool to treat antibiotic-resistant nature of biofilm-related infections in implanted medical devices.

Antimicrobial Stewardship in Neonates: Challenges and Opportunities

Neonatal infections result in significant morbidity and mortality. Antibiotics are vital for the treatment of infections but disrupt the neonatal microbiome, put the infant at risk for an adverse drug reaction, and may lead to the development of antibiotic resistance. Immediately after birth, clinicians must determine which infants require empiric antibiotics. Online risk stratification tools may provide a superior approach to decision trees. In infants who require empiric therapy for early-onset sepsis, ampicillin and an aminoglycoside with dosing based on recent pharmacokinetic studies represents the most appropriate first-line agents; third-generation cephalosporins should be reserved for patients with a high likelihood of Gram-negative meningitis. An antistaphylococcal penicillin and gentamicin should be utilized for suspected late-onset sepsis. Vancomycin and other broad-spectrum agents are reserved for patients with a history of resistant organisms. Antibiotic duration should be guided by understanding the clinical indications and obtaining the necessary cultures appropriately (i.e., adequate volume blood cultures). In the absence of a positive culture, antibiotic duration should often be limited. Individual institutions should leverage a multidisciplinary, interprofessional team to identify opportunities for antimicrobial stewardship. A collaborative, transparent system is required to change unit culture and generate a sustained impact on antibiotic utilization with optimal patient outcomes.

New Threats from an Old Foe: Methicillin-Resistant Staphylococcus aureus Infections in Neonates

Methicillin-resistant Staphylococcus aureus (MRSA) is a ubiquitous human inhabitant and one of the important pathogens of neonatal infections. MRSA is associated with significant mortality and morbidity, especially in very immature preterm neonates. Moreover, MRSA may be implicated in adverse long-term neonatal outcomes, posing a substantial disease burden. Recent advances in molecular microbiology have shed light on the evolution of MRSA population structure and virulence factors, which may contribute to MRSA epidemic waves worldwide. Equipped with remarkable genetic flexibility, MRSA has successfully developed resistance to an extensive range of antibiotics including vancomycin, as well as antiseptics. In the face of these new challenges from MRSA, our armamentarium of anti-infective strategies is very limited and largely dependent on prevention measures. Active surveillance cultures followed by decolonization may be a promising approach to control MRSA infections, with its efficacy and safety in the specific population of neonates yet to be addressed by large multicenter studies.

Risk Factors for Staphylococcus aureus Acquisition in the Neonatal Intensive Care Unit: A Matched Case-Case-Control Study

OBJECTIVE To determine risk factors independent of length of stay (LOS) for Staphylococcus aureus acquisition in infants admitted to the neonatal intensive care unit (NICU). DESIGN Retrospective matched case-case-control study. SETTING Quaternary-care referral NICU at a large academic children's hospital. METHODS Infants admitted between January 2014 and March 2016 at a level IV NICU who acquired methicillin resistant (MRSA) or susceptible (MSSA) S. aureus were matched with controls by duration of exposure to determine risk factors for acquisition. A secondary post hoc analysis was performed on the entire cohort of at-risk infants for risk factors identified in the primary analysis to further quantify risk. RESULTS In total, 1,751 infants were admitted during the study period with 199 infants identified as having S. aureus prevalent on admission. There were 246 incident S. aureus acquisitions in the remaining at-risk infant cohort. On matched analysis, infants housed in a single-bed unit were associated with a significantly decreased risk of both MRSA (P=.03) and MSSA (P=.01) acquisition compared with infants housed in multibed pods. Across the entire cohort, pooled S. aureus acquisition was significantly lower in infants housed in single-bed units (hazard ratio,=0.46; confidence interval, 0.34-0.62). CONCLUSIONS NICU bed design is significantly associated with S. aureus acquisition in hospitalized infants independent of LOS. Infect Control Hosp Epidemiol 2018;39:46-52.

Surveillance and Isolation of Methicillin-Resistant Staphylococcus aureus Colonization in the Neonatal Intensive Care Unit

BACKGROUND

Neonatal sepsis causes 1.4 million (36%) neonatal deaths annually. Staphylococcus aureus (SA), a common skin pathogen, remains the second leading cause of late-onset sepsis in the neonatal intensive care unit (NICU). Methicillin-resistant Staphylococcus aureus (MRSA), a resistant strain of SA, has created a significant global communicable health risk, especially in the NICU.

PURPOSE

To examine evidence related to NICU infection control practices surrounding MRSA surveillance, identification, and isolation in response to the clinical question, "What strategies should be universally implemented in the NICU to identify and prevent the spread of MRSA?"

METHODS/SEARCH STRATEGY

Databases were examined for articles on the topical area of MRSA in the neonate. Key terms were used to streamline the search, resulting in 20 primary works and 3 guideline/consensus statements considered imperative in response to the clinical questions.

FINDINGS/RESULTS

Hand hygiene remains the cornerstone to sound infection control practice. Colonization often leads to systemic infection, with smaller neonates at greatest risk. Hospital infection control compliance has improved outcomes. MRSA surveillance has reduced horizontal spread. No universal, specific recommendations exist to guide surveillance and management of MRSA in the NICU.

IMPLICATIONS FOR PRACTICE

Standardized guidelines with procedures for hand hygiene, patient surveillance and isolation, and patient cohorting with recommended staffing patterns should guide practice in the NICU. Both MRSA culture and polymerase chain reaction effectively identify positive patients. Decolonization practices are not yet clear.

IMPLICATIONS FOR RESEARCH

Evaluation of standard isolation practices versus outbreak response and approaches to neonatal decolonization should be evaluated for efficacy, safety, and resistance.

Managing skin and soft-tissue infection and nosocomial pneumonia caused by MRSA: a 2014 follow-up survey

As a follow-up to our 2009 survey, in order to explore opinion and practice on the epidemiology and management of meticillin-resistant Staphylococcus aureus (MRSA) in Europe, we conducted a second survey to elicit current opinions on this topic, particularly around antibiotic choice, dose, duration and route of administration. We also aimed to further understand how the management of MRSA has evolved in Europe during the past 5 years. Members of an expert panel of infectious diseases specialists convened in London (UK) in January 2014 to identify and discuss key issues in the management of MRSA. Following this meeting, a survey was developed comprising 36 questions covering a wide range of topics on MRSA complicated skin and soft-tissue infection and nosocomial pneumonia management. The survey instrument, a web-based questionnaire, was sent to the International Society of Chemotherapy for distribution to registered European infection societies and their members. This article reports the survey results from the European respondents. At the time of the original survey, the epidemiology of MRSA varied significantly across Europe and there were differing views on best practice. The current findings suggest that the epidemiology of healthcare-associated MRSA in Europe is, if anything, even more polarised, whilst community-acquired MRSA has become much more common. However, there now appears to be a much greater knowledge of current treatment/management options, and antimicrobial stewardship has moved forward considerably in the 5 years since the last survey.

Genotyping of Methicillin Resistant Staphylococcus aureus Strains Isolated from Hospitalized Children

Community associated methicillin resistant Staphylococcus aureus (CA-MRSA) is an emerging pathogen increasingly reported to cause skin and soft tissue infections for children. The emergence of highly virulencet CA-MRSA strains in the immunodeficiency of young children seemed to be the basic explanation of the increased incidence of CA-MRSA infections among this population. The subjects of this study were 8 patients hospitalized in the Pediatric Department at the University Hospital of Monastir. The patients were young children (aged from 12 days to 18 months) who were suffering from MRSA skin infections; two of them had the infections within 72 h of their admission. The isolates were classified as community isolates as they all carried the staphylococcal cassette chromosome mec (SCCmec) IV and pvl genes. Epidemiological techniques, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST), were applied to investigate CA-MRSA strains. Analysis of molecular data revealed that MRSA strains were related according to PFGE patterns and they belonged to a single clone ST80. Antimicrobial susceptibility tests showed that all strains were resistant to kanamycin and 2 strains were resistant to erythromycin.

Staphylococcus aureus in a neonatal care center: methicillin-susceptible strains should be a main concern

BACKGROUND

In the context of a methicillin-susceptible Staphylococcus aureus (MSSA) outbreak, we aimed to improve our knowledge of S. aureus (SA) epidemiology in the neonatal care center (NCC) of a tertiary care teaching hospital.

METHODS

We performed a complete one-year review of SA carrier, colonized or infected patients. Monthly prevalence and incidence of SA intestinal carriage, colonization and infection were calculated and the types of infection analysed. During the MSSA outbreak, strains were studied for antimicrobial resistance, content of virulence genes and comparative fingerprint in Pulsed-Field Gel Electrophoresis. Hand hygiene and catheter-related practices were assessed by direct observational audits. Environmental investigation was performed in search of a SA reservoir.

RESULTS

Epidemiological analyses showed 2 or 3 prevalence peaks on a background of SA endemicity. In the NCC, during 2009, overall MSSA prevalence did not decrease below 5.5%, while mean MRSA prevalence was about 1.53%. Analysis of infection cases revealed that the outbreak corresponded to the emergence of catheter-related infections and was probably related to the relaxation in infection control practices in a context of high colonization pressure. Health care workers' white coats appeared as a potential environmental reservoir that could perpetuate SA circulation in the ward.

CONCLUSION

This report emphasizes the importance of integrating MSSA along with methicillin-resistant SA in a program of epidemiological surveillance in the NCC.

The mother as most important risk factor for colonization of very low birth weight (VLBW) infants with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E)

OBJECTIVES

This study aimed to determine the prevalence of and risk factors for colonization with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) and methicillin-resistant Staphylococcus aureus (MRSA) in very low birth weight (VLBW; <1500 g) infants and their mothers.

METHODS

This investigation was conducted in the perinatal centre at the Charité Berlin between May 2012 and June 2013. VLBW infants and their mothers were screened for colonization with ESBL-E and MRSA. Demographic and clinical data were obtained from the German nationwide surveillance system for nosocomial infections in VLBW infants (NEO-KISS) and used to perform univariate and multivariate analyses.

RESULTS

Of 209 VLBW infants, 12 (5.7%) were colonized with ESBL-E. Eighteen of 209 (8.6%) ESBL-E-tested neonates were related to an ESBL-E-positive mother. Univariate analysis, strain typing and multivariate analysis (OR 7.4, 95% CI 2.1-26.7, P = 0.002) identified an ESBL-E-positive mother and maternal-neonatal transmission as a main source of colonization. The prevalence of MRSA was 2.3% (5 of 221) among VLBW infants. One of the 221 (0.5%) MRSA-tested neonates was related to an MRSA-positive mother. No risk factors for transmission of MRSA could be detected in this study.

CONCLUSIONS

Our study demonstrated that maternal-neonatal transmission of ESBL-E from mother to child is an important risk factor for colonization of VLBW infants. As a consequence, routine ESBL-E screening of neonates and mothers should be considered as a means of reducing neonatal morbidity and mortality.

Methicillin-resistant Staphylococcus aureus colonization: a three-year prospective study in a neonatal intensive care unit in Italy

BACKGROUND

Methicillin resistant Staphylococcus aureus (MRSA) is a major etiological agent of infection in neonatal intensive care units (NICUs). Routes of entry of this organism can be different and the transmission pathway complex. Colonized neonates are the main endogenous reservoir.

METHODS AND RESULTS

We conducted a prospective three-year study on MRSA colonization recruiting 722 neonates admitted between 2009 and 2012. Nasal swabs were cultured weekly and MRSA isolates were submitted to molecular typing. The annual incidence density of acquisition of MRSA ranged from a maximum of 20.2 cases for 1000 patient-days during the first year to a minimum of 8.8 cases in the second one to raise again up to 13.1 cases during the third year. The mean weekly colonization pressure fluctuated from 19.1% in the first year to 13.4% in the second year and 16.8% in the third year. It significantly correlated with the number of MRSA acquisitions in the following week. Overall, 187 (25.9%) subjects tested positive for MRSA. A non multiresistant, tst positive, ST22-MRSA-IVa spa t223 strain proved to be endemic in the NICU, being identified in 166 (88.8%) out of 187 colonized neonates. Sporadic or epidemic occurrence of other strains was detected.

CONCLUSIONS

An MRSA strain belonging to the tst1 positive, UK-EMRSA-15/ "Middle Eastern Variant" appeared to be endemic in the NICU under investigation. During the three-year period, substantial changes occurred in case-mix of patients moving towards a higher susceptibility to MRSA colonization. The infection control procedures were able to decrease the colonization rate from more than 40% to approximately 10%, except for an outbreak due to a CA-MRSA strain, ST1-MRSA-IVa, and a transient increase in the colonization prevalence rate coincident with a period of substantial overcrowding of the ward. Active surveillance and molecular typing contributed to obtain a reliable picture of the MRSA dissemination in NICU.