Epidemiology and antimicrobial susceptibility of Staphylococcus aureus in children in a tertiary care pediatric hospital in Milan, Italy, 2017—2021

Abstract

Background Methicillin-resistant Staphylococcus aureus (MRSA) is highly prevalent worldwide and can cause severe diseases. MRSA is associated with other antibiotic resistance. COVID-19 pandemic increased antimicrobial resistance in adult patients. Only a few data report the antimicrobial susceptibility of S. aureus in the Italian pediatric population, before and during the COVID-19 pandemic. Methods We included all the S. aureus positive samples with an available antibiogram isolated from pediatric patients (< 18 years old) in a tertiary care hospital in Milan, Italy, from January 2017 to December 2021. We collected data on demographics, antimicrobial susceptibility, and clinical history. We compared methicillin-susceptible Staphylococcus aureus (MSSA) and MRSA strains. We calculated the frequency of isolation by year. The incidence of isolates during 2020 was compared with the average year isolation frequency using the univariate Poisson test. We compared the proportion of MRSA isolates during 2020 to the average proportion of other years with the Chi-squared test. Results Our dataset included a total of 255 S. aureus isolated from 226 patients, 120 (53%) males, and 106 (47%) females, with a median age of 3.4 years (IQR 0.8 – 10.5). The mean isolation frequency per year was 51. We observed a significant decrease of isolations during 2020 (p = 0.02), but after adjusting for the total number of hospitalization per year there was no evidence that the incidence changed. Seventy-six (30%) S. aureus were MRSA. Twenty (26%) MRSA vs 23 (13%) MSSA (p = 0.02) were hospital-acquired. MRSA strains showed higher resistance to cotrimoxazole, clindamycin, macrolides, levofloxacin, gentamicin, and tetracyclin than MSSA strains. None of MRSA were resistant to linezolid and vancomycin, one was resistant to daptomycin. The proportion of MRSA did not change during the COVID-19 pandemic. The overall clindamycin resistance was high (17%). Recent antibiotic therapy was related to MRSA infection. Conclusion The proportion of MRSA did not change during the COVID-19 pandemic and remained high. Clindamycin should not be used as an empirical MRSA treatment due to its high resistance.

Evaluation of the in-vitro synergistic potential of vancomycin combined with other antimicrobial agents against methicillin-resistant Staphylococcus aureus isolates

“…In this study, resistance to trimethoprimsulphamethoxazole (SXT) was detected in (46%) of the isolates, rifampin resistance was detected in (34%), while clindamycin resistance in the current study was detected in 24% , these resistance rates are higher than Poland, Turkey, Italy and the USA [29,32]. On the contrary, only 8% of the isolates demonstrated resistance to chloramphenicol, this low resistance rate can be explained by the fact that physicians now refrain from using chloramphenicol due to its numerous side effects.…”

Phenotypic and Genotypic Detection of Antimicrobial Resistance and Virulence Factors among Staphylococcus aureus Clinical Isolates

“…In this study, S. aureus had represented 37.5% of Gram-positive cocci isolates from hospital acquired infections (20.7% were MRSA and 16.8% were MSSA). Matching Egyptian study done by El Shimy et al [7] [23]. So, proper antibiotic stewardship program is strongly recommended to keep the benefit of these antibiotics in treatment of MRSA infections with reinforcement of infection control measures to limit the spread of vancomycin non-susceptible isolates within our hospitals and using of more accurate methods in S.aureus identification such as MALDI-TOF or PCR as some coagulase-negative staphylococci (CoNS) can be misinterpreted as S.aureus by manual biochemical reactions.…”

MRSA compendium of epidemiology, transmission, pathophysiology, treatment, and prevention within one health framework

“…Recent trend in the prevalence of HA-MRSA was noted varying among the countries for example it was noted higher 58.4% from Portugal in 2013 ( Tavares et al, 2013 ), 46% from India in 2009 ( Arora et al, 2010 ), 52% from Pakistan in 2017 ( Siddiqui et al, 2017 ), 45% from China from 2015 to 2017 ( Chen et al, 2022 ), and 38.9% from Norway from 2008 to 2016 ( Enger et al, 2022 ). However, with the increasing prevalence of HA-MRSA in different countries, MRSA prevalence also noted lower in many such as 4.6% from Germany ( Sassmannshausen et al, 2016 ), 25% from Texas ( Davis et al, 2004 ), 19.1% from Mexico ( Hamdan-Partida et al, 2022 ), 15.1% from Australia ( Coombs et al, 2022 ), and 26% from Italy ( La Vecchia et al, 2022 ) are summarized in Table 1 . Similar increasing and decreasing trend of MRSA prevalence from different countries also noted for CA-MRSA such as 79% from Japan ( Ogura et al, 2022 ), 84.9% from Australia ( Coombs et al, 2022 ), 64.7% from India ( Alvarez-Uria and Reddy, 2012 ), 61% from Norway ( Enger et al, 2022 ), and 44.3% from Iran ( Tabandeh et al, 2022 ) with lower prevalence from Egypt (16%) ( Mostafa et al, 2022 ), China [1.7% ( Bi et al, 2018 ); 24% ( Chen et al, 2022 )], 7.3% from Gerorgia ( Hidron et al, 2005 ), and 12.8% from Switzerland ( Harbarth et al, 2005 ).…”