Secondary bacterial infections & extensively drug-resistant bacteria among COVID-19 hospitalized patients at the University Hospital in Kraków.

INTRODUCTION: Healthcare-associated infections (HAI) and bacterial antimicrobial resistance posed a therapeutic risk during the coronavirus disease 2019 (COVID-19) pandemic. The aim of this study was to analyze the HAIs in COVID-19 patients in the Intensive Care Unit (ICU) and non-ICU at the University Hospital in Krakow (UHK) with an emphasis on the susceptibility of the most frequently isolated pathogens and the prevalence of extensively drug resistant (XDR) microorganisms. METHODS: This laboratory-based study was carried out at the University Hospital in Krakow in the ICU and non-ICUs dedicated to COVID-19 patients between May 2021 and January 2022. All isolates of Klebsiella pneumoniae were analyzed using PFGE protocol. RESULTS: 292 independent HAI cases were identified, with the predominance of urinary tract infections (UTI), especially in the non-ICU setting. The most common ICU syndrome was pneumonia (PNA). The prevalence of XDR organisms was 22.6% in the ICU and 14.8% in non-ICUs among all isolates. The incidence of carbapenem-resistant Enterobacteriaceae infection was 24.8 cases per 10,000 hospitalizations and the carbapenem-resistant A. baumannii infection incidence was 208.8 cases per 10,000 hospitalizations. The prevalence of XDR strains was highest in Acinetobacter spp, in PNA cases. The PFGE typing demonstrated that almost all XDR strains varied widely from each other. CONCLUSIONS: In this study, there was a high incidence of HAI in COVID-19 patients, especially when compared to Western Europe and the United States. Similarly, the prevalence of XDR microorganisms, especially XDR-A.baumannii, was also high. PFGE did not confirm the horizontal spread of any organism strains.

Antimicrobial Resistance in Enterobacterales Bacilli Isolated from Bloodstream Infection in Surgical Patients of Polish Hospitals.

BACKGROUND AND AIMS: Bloodstream infections (BSIs) are one of the most frequently observed hospital-acquired infections (HAIs). We sought to describe the epidemiology and drug resistance secondary Enterobacterales BSIs in surgical patients and check for any correlation with the type of hospital ward. MATERIALS AND METHODS: This multicenter (13 hospitals in southern Poland) laboratory-based retrospective study evaluated adults diagnosed with BSI secondary to surgical site infection (SSI) hospitalized in 2015-2018; 121 Enterobacterales strains were collected. The drug resistance was tested according to the EUCAST recommendations. Tests confirming the presence of extended-spectrum ß-lactamases (ESBLs) and bla resistance genes were carried out. The occurrence of possible clonal epidemics among K. pneumoniae strains was examined. RESULTS: The prevalence of Enterobacterales in secondary BSI was 12.1%; the most common strains were E. coli (n = 74, 61.2%) and Klebsiella spp. (n = 33, 27.2%). High resistance involved ampicillin and ampicillin/sulbactam (92, 8-100%), fluoroquinolones (48-73%), and most cephalosporins (29-50%). Carbapenems were the antimicrobials with the susceptibility at 98%. The prevalence of ESBL strains was 37.2% (n = 45). All the ESBL strains had bla CTX-M gene, 26.7% had the bla SHV gene, and 24.4% had bla TEM gene. The diversity of Klebsiella strains was relatively high. Only 4 strains belonged to one clone. CONCLUSIONS: What is particularly worrying is the high prevalence of Enterobacterales in BSI, as well as the high resistance to antimicrobial agents often used in the empirical therapy. To improve the effectiveness of empirical treatment in surgical departments, we need to know the epidemiology of both surgical site infection and BSI, secondary to SSI. We were surprised to note high heterogeneity among K. pneumoniae strains, which was different from our previous experience.

Molecular analysis of meticillin-resistant Staphylococcus aureus strains isolated from different types of infections from patients hospitalized in 12 regional, non-teaching hospitals in southern Poland.

BACKGROUND: Accumulated data indicate that meticillin-resistant Staphylococcus aureus (MRSA) infections are associated with a worse prognosis than methicillin-susceptible S. aureus infections. AIM: To assess the epidemiological profile of S. aureus infections and the genetic diversity of clinical strains of MRSA in 12 hospitals in southern Poland. METHODS: Samples from bloodstream infections, pneumonia, and skin and soft tissue infections from adult patients were examined. S. aureus isolates were tested for MRSA and macrolide-lincosamide-streptogramin B (MLSB) phenotypes. Staphylococcal cassette chromosome mec (SCCmec) typing and S. aureus protein A (spa) typing were performed. Analysis of the genetic similarity was performed by pulsed-field gel electrophoresis. RESULTS: This study included 555 patients. An MRSA phenotype was detected in 15.1% of strains. The prevalence of MRSA infection was higher in patients aged >80 years. An MLSB phenotype was detected in 18.2% of strains. Analysis of SmaI profiles did not reveal a dominant clone. Spa typing showed 25 different spa types, and spa type t003 was the most common (49% of strains). Among MRSA strains, SCCmecII (49%) and SCCmecIV (27.4%) were predominant. CONCLUSION: The characteristics of MRSA showed considerable heterogeneity. The results demonstrate the need for caution when drawing conclusions on direct epidemiological relationships between isolates based on a single typing method. As the cases of infection in this study were not associated with the hospital environment and horizontal transfer, a focus on screening at hospital admission, and appropriate infection control, may help to reduce the risk of MRSA infections.

Urinary tract infections caused by Pseudomonas aeruginosa among children in Southern Poland: Virulence factors and antibiotic resistance.

OBJECTIVE: The aim of this study was to analyze antibiotic resistance and virulence patterns in Pseudomonas aeruginosa (PAR) isolates from urinary tract infections among children in Southern Poland. MATERIALS AND METHODS: This study comprised consecutive, non-repetitive PAR isolates sent from two collaborative laboratories. The study group consisted of children aged up to 17 years from Southern Poland with culture-proven PAR UTIs. Relevant information about patients with UTIs, such as age, sex, and type of infection (polymicrobial or monomicrobial), was collected. Isolates were screened for major virulence factors found in uropathogenic PAR strains. Multidrug-resistant (MDR) strains were defined as strains not susceptible to one antimicrobial in at least three different antimicrobial classes. Extensively drug resistant (XDR) strains were defined as strains susceptible to no more than two antimicrobial classes. RESULTS: The total prevalence of PAR UTIs was 2.1%, and in children <5 years of age it was 3.0%. A total of 26 isolates was tested: 21 from outpatients and five from inpatients. Most infections (80.8%) occurred in children ≤ 4 years of age. The most prevalent virulence gene was exoY (96.2%). The prevalence of other effector proteins was 88.5% for exoT, 92.3% for exoS, and 19.2% for exoU. The gene for LasB was present in 80.8% of isolates; the gene for AprA in 61.5%; the gene for PilA in 19.2%; and the gene for PilB was not detected. The PAR isolates were generally susceptible to beta-lactam and aminoglycoside antimicrobials. All isolates were also susceptible to colistin. A large proportion of isolates were resistant to carbapenems and fluoroquinolones (Fig. 1). No significant differences were found in antimicrobial resistance between males and females or inpatients and outpatients (p > 0.05 for all tested antimicrobials), or in antimicrobial resistance between younger (≤ 5 years old, n = 21) and older (> 5 years old, n = 5) children (p > 0.05 for all tested antimicrobials). Two isolates were classified as XDR and none as MDR. The EDTA test yielded one MBL-positive isolate (3.8%), from a 17-year-old patient in home care. No isolates with genes for the KPC, IMP, or VIM were identified. CONCLUSION: As data on UTIs in children with Pseudomonas etiology are scarce, this paper provides useful information for clinicians and allows for comparison between Poland and other countries. Our findings have important implications for clinicians treating UTIs empirically, because the success of empiric treatment is based on knowledge of pathogen antimicrobial susceptibility patterns.

Control of an outbreak of Acinetobacter baumannii infections using vaporized hydrogen peroxide.

BACKGROUND: Multidrug-resistant Acinetobacter baumannii (MRAB) is a serious nosocomial pathogen characterized by its survival on inanimate surfaces for long periods, making control of outbreaks difficult. AIM: To analyse two hospital outbreaks caused by MRAB, determine their epidemiology, carbapenem-resistance mechanisms and assess the effectiveness of surface disinfection by vaporized hydrogen peroxide (VHP). METHODS: MRAB strains were isolated from patients in two intensive care units (ICUs). Antimicrobial susceptibility testing was performed by E-test. Polymerase chain reaction (PCR) was used to detect the presence of the most common A. baumannii carbapenemases. Epidemiological typing was performed by rep-PCR (DiversiLab) and pulsed-field gel electrophoresis. VHP was used to decontaminate the affected ICUs. FINDINGS: MRAB was isolated from 28 patients between January 2009 and September 2010. All isolates were resistant to ciprofloxacin and gentamicin. Twenty-one were also resistant to carbapenems. Carbapenem resistance was associated primarily with the acquired OXA-23-like enzyme. Genotyping revealed three clones; the predominant clone corresponded to the international clone (IC) 2. Typing of the isolates pointed to a multifocal outbreak without a single source of infection, with horizontal spread of the dominating clone among ICU patients. A combination of rigorous infection control measures including strict isolation, education of staff, hand hygiene and surface decontamination using VHP halted the outbreak. CONCLUSION: The results of this study confirm the importance of rigorous infection prevention and control measures, combined with VHP decontamination in controlling an outbreak of MRAB.

Comparison of SSI rates in endoarthroplasty of hip and knee in a Cracow patient population and the importance of postdischarge surveillance.

BACKGROUND: The aim of the study was to analyse the epidemiological and microbiological analysis of surgical site infections in patients that underwent knee or hip endoarthroplasty procedures. MATERIALS AND METHODS: The epidemiological and microbiological surveillance was carried out by the local infection control team in cooperation with the Department of Bacteriology, at the Chair of Microbiology, Jagiellonian University Medical College in Cracow. RESULTS: A total of 651 patients operated in the Department of Orthopedics, Trauma Surgery and Rehabilitation of Cracow Rehabilitation Center in Poland were analyzed. Twenty-three cases of SSI were detected. The cumulative incidence after hip prosthesis (HPRO) procedures was 2.3%, while for knee prosthesis (KPRO) it was 7.0. Standardized risk index, comparing the incidence in our study to German hospitals, shows a statistically significant, higher incidence in patients with knee replacement procedures in our study (p=0.004). Among etiological agents of SSIs, we demonstrated the dominating role of Gram-positive cocci to be 75% (30% methicillin resistant). This resistance was confirmed only in case of coagulasenegative staphylococci (no MRSA were cultured). Gramnegative rods were isolated with a frequency of 25%: 41.6% in SSI after hip endoarthroplasty and 15% after knee endoarthroplasty. Postdischarge surveillance encompassed 59% of operated patients. CONCLUSION: The incidence of SSIs of hip prosthesis in our study was comparable to the incidence in the German KISS program, where surveillance is integrating a highly sensitive postdischarge detection. On the other hand, we observed a higher, statistically significant cumulative incidence in case of knee endoarthroplasty. Our microbiological data show effective control of methicillin-resistant Staphylococcus aureus and are also in agreement with the data found in literature referring to coagulasenegative multi-resistant staphylococci as an important problem in the orthopaedic surgery of the knee joint.