Antibiotic Susceptibility Data Research Articles

Antibiotic Resistance Pattern of Bacteria Isolated from Clinical Specimens: A Hospital-Based Cross-sectional Study in Kathmandu, Nepal

Antibiotics are vital in combating infectious diseases, yet their increasing use fosters resistance. Antimicrobial resistance (AMR) is rising in Nepal due to factors such as indiscriminate, inappropriate, and inadequate antibiotic usage. This study aims to explore the association between demographic factors and the prevalence of specific bacterial strains within the surveyed population. Additionally, it seeks to determine the antibiotic resistance patterns of these bacteria. Antibiotic susceptibility or resistance data were retrieved from the Medical Records Department (MRD) of the Manmohan Memorial Medical College and Teaching Hospital (MMMCTH) in Kathmandu. Samples from patients with certain types of bacterial infections were included, with 56 from sputum reports, 46 from urine, and 8 from blood samples out of 110 retrieved. Analysis revealed that sputum samples were mostly from older males, while urine samples were mostly from females. Yet, gender did not significantly influence bacterial presence across sample types. Overall, Escherichia coli was the most prevalent bacterium (74%), followed by Salmonella typhi (25%), Staphylococcus aureus (25%), and Klebsiella pneumoniae (23%) isolated from different type of clinical samples. Altogether, 6-15 antibiotics were assessed for sensitivity, with 2–6 antibiotics showing sensitivity to blood bacteria, 1-6 antibiotics demonstrating sensitivity to sputum bacteria, and 3–8 antibiotics exhibiting sensitivity to urine bacteria. Many investigated antibiotics were resistant, only gentamicin exhibited sensitivity for all types of bacteria found in blood, sputum and urine. These findings underscore the importance of discerning bacterial resistance patterns for effective antimicrobial treatment selection.

Assessment of wound cultures in an oncology hospital

Purpose: The aim of this study is to evaluate the patient's demographic, clinical and laboratory data to determine whether the bacteria isolated from wound cultures are causative agents or colonization, and to determine their antimicrobial susceptibilities. Materials and methods: This research was conducted in XXXX between January 1, 2021 and December 31, 2022. Two hundred thirty six isolates from 186 patients wound cultures were included in the study. Demographic data, clinical data and laboratory results of the patients were evaluated. The isolated bacteria and their antimicrobial susceptibilities were determined. The Q score system was used to evaluate the microbiological quality of wound samples. Results: One hundred fifty nine cases (85%) were inpatients. Totally 119 (63.9%) patients were diagnosed with infection. The Q score for 136 samples (85.5%) was assessed as Q3. The most common isolated microorganisms were coagulase negative-staphylococci (CoNS) (19%), E.coli (14.8%), and S.aureus (13.1%), respectively in wound bacterial cultures. The methicillin resistance rate was 55.5% in CoNS and 54.1% in S.aureus. Gram-negative bacteria were isolated in 81 (59.9%) infected patients. Among the infected patients, 39 (32.7%) patients had surgical site infections, 25 (21%) prosthesis infections, and diabetic foot infections 3 (2.5%). Infection rates were statistically significantly higher in patients with surgery, prosthesis, and diabetic foot (p=0.054). Conclusion: In conclusion, Q score is a strong marker in diagnosing wound infection and excluding colonization and helps prevent unnecessary antibiotic use. Local antibiotic susceptibility data should be examined up-to-date in the empirical treatment of special patient groups such as oncological patients.

Anticipated Effects of Higher-valency Pneumococcal Conjugate Vaccines on Colonization and Acute Otitis Media.

Bacterial etiologies of acute otitis media (AOM) have shifted from the introduction of pneumococcal conjugate vaccines (PCVs), antibiotic selection and competition among species. We characterized Streptococcus pneumoniae ( Spn ), Haemophilus influenzae ( Hflu ) and Moraxella catarrhalis ( Mcat ) in the nasopharynx during well-child healthy visits and at the onset of AOM, and in middle ear fluid (MEF) of children with AOM to assess anticipated effects of higher-valency PCVs (PCV15 and PCV20). From September 2021 to September 2023, we conducted a prospective longitudinal cohort study of PCV13 immunized children 6-36 months old. MEF was collected via tympanocentesis. Serotyping and antibiotic susceptibility testing were performed on Spn , Hflu and Mcat isolates. We obtained 825 nasopharyngeal and 216 MEF samples from 301 children. The order of frequency of nasopharyngeal colonization was Mcat , Spn and Hflu ; Hflu was the predominant otopathogen in MEF. Among Spn isolates, non-PCV15, non-PCV20 serotypes predominated in the nasopharynx and in MEF; the most frequent serotype was 35B. Among MEF samples, 30% of Spn isolates were amoxicillin nonsusceptible; 23% of Hflu isolates and 100% of Mcat isolates were β-lactamase-producing. The majority of Spn isolates among young children were non-PCV15, non-PCV20 serotypes, especially serotype 35B; therefore, the impact of higher-valency PCVs in reducing pneumococcal colonization or AOM is expected to be limited. Hflu continues to be the most frequent AOM pathogen. Antibiotic susceptibility data suggest a high dose of amoxicillin/clavulanate or alternative drugs that are effective against contemporary mix of otopathogens could be considered for optimal empiric selection to provide the best efficacy.

Patterns of Antibiotic Resistance in Urinary Tract Infections: A Retrospective Observational Study.

Urinary tract infections (UTIs) are among the most common bacterial infections, and antibiotic resistance complicates empiric treatment. This study aimed to describe recent resistance patterns among uropathogens in a tertiary-care teaching hospital to optimize empiric UTI management. This retrospective observational study included 280 patients diagnosed with UTIs at the Dr. Patnam Mahender Reddy Institute of Medical Sciences, Hyderabad, over a six-month period from June 2023 to November 2023. Urine culture and antibiotic susceptibility data were collected from electronic medical records. Patient demographics, including age, sex, and comorbid diabetes, were recorded. Causative uropathogens and their resistance rates to commonly prescribed UTI antibiotics were analyzed. Empiric antibiotic treatment patterns and outcomes were talked about. These included clinical cure, recurrence, susceptibility match, and microbiologic eradication. The mean age of patients was 43.5 years, with 196 (70%) being female and 70 (25%) having diabetes. Escherichia coli caused 210 (75%) of UTIs, Klebsiella pneumoniae 42 (15%), Proteus mirabilis 14 (5%), Enterococcus faecalis 8 (3%), and Staphylococcus saprophyticus 6 (2%). E. coli resistance rates were 48% for ampicillin, 25% for ciprofloxacin, 18% for trimethoprim/sulfamethoxazole (TMP/SMX), and 5% for nitrofurantoin. K. pneumoniae resistance rates were 89% for ampicillin, 67% for ciprofloxacin, 44% for TMP/SMX, and 22% for nitrofurantoin. The most frequently prescribed antibiotic was nitrofurantoin (45%), then ciprofloxacin (35%). Clinical cure was achieved in 75% of cases. Recurrent UTIs within four weeks occurred in 25% of cases. Treatment matched urine culture susceptibility in 82% of patients. The rising fluoroquinolone resistance highlights the need for current local data to guide empiric UTI treatment. Nitrofurantoin had low resistance rates and was an effective first-line therapy. Ongoing monitoring of resistance patterns in UTIs is essential to optimize antibiotic selection.

Comparative Pharmacokinetics of Gentamicin C1, C1a and C2 in Healthy and Infected Piglets.

Gentamicin, an aminoglycoside antibiotic, is a mixture of therapeutically active C1, C1a, C2 and other minor components. Despite its decades-long use in pigs and other species, its intramuscular (IM) pharmacokinetics/pharmacodynamics (PKs/PDs) are unknown in piglets. Furthermore, the PKs of many drugs differ between healthy and sick animals. Therefore, we investigated the PKs of gentamicin after a single IM dose (10 mg/kg) in healthy piglets and piglets that were intranasally co-infected with Actinobacillus pleuropneumoniae and Pasteurella multocida (PM). The plasma concentrations were measured using validated liquid chromatography/mass spectrometry. The gentamicin exposure was 36% lower based on the area under the plasma concentration-time curve and 16% lower based on the maximum plasma concentration (Cmax) in the infected piglets compared to the healthy piglets, while it was eliminated faster (shorter half-life and larger clearance) in the infected piglets compared to the healthy piglets. The clearance and volume of distribution were the highest for the C1 component. C1, C1a and C2 accounted for 22-25%, 33-37% and 40-42% of the total gentamicin exposure, respectively. The PK/PD target for the efficacy of aminoglycosides (Cmax/minimum inhibitory concentration (MIC) > 10) could be exceeded for PM, with a greater magnitude in the healthy piglets. We suggest integrating this PK information with antibiotic susceptibility data for other bacteria to make informed antibiotic and dosage regimen selections against piglet infections.

Predominance of multidrug-resistant bacteria causing urinary tract infections among symptomatic patients in East Africa: a call for action.

In low- and middle-income countries, antibiotics are often prescribed for patients with symptoms of urinary tract infections (UTIs) without microbiological confirmation. Inappropriate antibiotic use can contribute to antimicrobial resistance (AMR) and the selection of MDR bacteria. Data on antibiotic susceptibility of cultured bacteria are important in drafting empirical treatment guidelines and monitoring resistance trends, which can prevent the spread of AMR. In East Africa, antibiotic susceptibility data are sparse. To fill the gap, this study reports common microorganisms and their susceptibility patterns isolated from patients with UTI-like symptoms in Kenya, Tanzania and Uganda. Within each country, patients were recruited from three sites that were sociodemographically distinct and representative of different populations. UTI was defined by the presence of >104 cfu/mL of one or two uropathogens in mid-stream urine samples. Identification of microorganisms was done using biochemical methods. Antimicrobial susceptibility testing was performed by the Kirby-Bauer disc diffusion assay. MDR bacteria were defined as isolates resistant to at least one agent in three or more classes of antimicrobial agents. Microbiologically confirmed UTI was observed in 2653 (35.0%) of the 7583 patients studied. The predominant bacteria were Escherichia coli (37.0%), Staphylococcus spp. (26.3%), Klebsiella spp. (5.8%) and Enterococcus spp. (5.5%). E. coli contributed 982 of the isolates, with an MDR proportion of 52.2%. Staphylococcus spp. contributed 697 of the isolates, with an MDR rate of 60.3%. The overall proportion of MDR bacteria (n = 1153) was 50.9%. MDR bacteria are common causes of UTI in patients attending healthcare centres in East African countries, which emphasizes the need for investment in laboratory culture capacity and diagnostic algorithms to improve accuracy of diagnosis that will lead to appropriate antibiotic use to prevent and control AMR.

Real-world in vitro activity of newer antibiotics against Enterobacterales and Pseudomonas aeruginosa, including carbapenem-non-susceptible and multidrug-resistant isolates: a multicenter analysis.

New antibiotics have been developed to combat antibiotic-resistant Gram-negative pathogens, which are difficult to treat and associated with poor clinical outcomes. We conducted a multicenter evaluation of real-world testing practices and susceptibility to newer antibiotics. Our study included 71 facilities in the BD Insights Research Database (2018-2022) and involved adult patients with a positive culture for Enterobacterales or Pseudomonas aeruginosa and facility-reported antibiotic susceptibility data for cefiderocol (FDC), ceftazidime-avibactam (CZA), ceftolozane-tazobactam (C/T), eravacycline (ERV), imipenem-relabactam (I-R), or meropenem-vaborbactam (MVB). A total of 27,531 susceptibility results were available, including 22,111 (80.3%) Enterobacterales and 5,420 (19.7%) P. aeruginosa. Escherichia coli (11,882 [43.2%]) was the most frequently tested potential pathogen, and CZA (13,567 [49.3%]) and C/T (13,299 [48.3%]) had the greatest numbers of susceptibility results. For the other four antibiotics, susceptibility data were available for fewer than 2% of isolates. Susceptibility comparisons should be considered with caution. Among isolates tested, CZA had the highest susceptibility rates for total Enterobacterales (98.7%) and multidrug-resistant (92.9%) and carbapenem-non-susceptible (85.0%) isolates. For P. aeruginosa, FDC had the highest susceptibility rates for total (95.6%) and carbapenem-non-susceptible (93.3%) isolates. The susceptibility of carbapenem-non-susceptible Enterobacterales to CZA and C/T decreased modestly from 2020 to 2022, but carbapenem-non-susceptible P. aeruginosa susceptibility rates increased. We conclude that Gram-negative pathogens have high real-world susceptibility rates to newer antibiotics but may show important differences across resistance profiles. Newer antibiotics are a valuable option for the management of resistant Enterobacterales and P. aeruginosa. Additional effort may be required to integrate these agents into routine clinical care.IMPORTANCENewer antibiotics against Gram-negative pathogens provide important treatment options, especially for antibiotic-resistant bacteria, but little is known about their use during routine clinical care. To use these agents appropriately, clinicians need to have access to timely susceptibility data. We evaluated 27,531 facility-reported susceptibility results from the BD Insights Research Database to gain a better understanding of real-world testing practices and susceptibility rates for six newer antibiotics. Escherichia coli was the most frequently tested potential pathogen, and ceftazidime-avibactam and ceftolozane-tazobactam had the greatest numbers of susceptibility results. For cefiderocol, eravacycline, imipenem-relabactam, and meropenem-vaborbactam, susceptibility data were available for fewer than 2% of isolates. Susceptibility comparisons should be considered with caution. Ceftazidime-avibactam had the highest susceptibility rates for Enterobacterales while cefiderocol had the highest susceptibility rates for Pseudomonas aeruginosa. New antibiotics have the potential to improve the management of Gram-negative infections, but their use may be hampered by the absence of susceptibility data.

Case Commentary: An espresso, a free puppy, and multidrug-resistant Campylobacter.

Campylobacter species infections in immunocompromised patients have the potential to progress to bacteremia and other extra-intestinal diseases. There is a sparsity of robust data, including antibiotic susceptibility data for contemporary agents, upon which to base treatment decisions. Moreover, intrinsic antimicrobial resistance in Campylobacter spp. further limits treatment options. The current publication by Bonilla-Moreno et al. elaborates on this clinical dilemma through the development, treatment, and molecular investigation of the putative mechanisms of carbapenem resistance in an immunocompromised patient with Campylobacter coli bacteremia.

Comparing individual antimicrobial resistant and multi-drug resistant Salmonella enterica across serotypes, sampling sources, sampling periods, and food animal types in the United States (2014-2018).

This study aimed to compare the antimicrobial-resistant Salmonella enterica profiles from three sampling sources cecal contents, HACCP (during processing), and retail meat using phenotypic antibiotic susceptibility and serotype data gathered from 2014 and 2018. Antimicrobial resistance data for 29 major Salmonella serotypes from three sampling sources and associated food animal types (cattle, swine, chicken, and turkey) were obtained from the database of the United States National Antimicrobial Resistance Monitoring System. Using multivariable logistic regression models, we compared individual and multi-drug resistance (MDR) in Salmonella enterica between the three sampling sources, food animal types, sampling period, and Salmonella serotypes. Across the three sources and throughout the sampling period, the recovery of antimicrobial-resistant Salmonella enterica - including MDR, MDR-AmpC, and ACSSuT - among food animal types were dependent on the sampling period and, in some cases, sampling sources and period for the selected antimicrobials. The predicted probability of antimicrobial resistance was greater in Salmonella serotypes from turkey compared to other food animal types, conditional on sampling sources. Ceftriaxone-resistant (OR=0.83, 95% CI: 0.69-0.99), and Sulfisoxazole-resistant (OR=0.84, 95% CI: 0.72-0.98) Salmonella serotypes were less likely to be recovered from the Hazard Analysis and Critical Control Point (HACCP) sources than with the cecal sources. Except for Salmonella serotypes Dublin and Newport, most of the Salmonella serotypes were less likely to be resistant to the selected antimicrobials, or found as MDR, compared to serotype Typhimurium. This study offers an integrated view on the predicted probability of MDR Salmonella serotypes, as well as insights into which serotypes are persistent, emerging or declining across sampling sources and food animal types in the United States.

An increase in erythromycin resistance in methicillin-susceptible Staphylococcus aureus from blood correlates with the use of macrolide/lincosamide/streptogramin antibiotics. EARS-Net Spain (2004-2020).

To describe and analyse erythromycin resistance trends in blood isolates of Staphylococcus aureus (EARS-Net Spain, 2004-2020) and the association of these trends with the consumption of macrolide, lincosamide, and streptogramin B (MLSB) antibiotics. To assess molecular changes that could be involved in erythromycin resistance trends by whole genome analysis of representative isolates. We collected antibiotic susceptibility data for all first-blood S. aureus isolates in patients from 47 Spanish hospitals according to EARS-Net criteria. MLSB antibiotic consumption was obtained from the Spanish Agency for Medicines and Medical Devices (2008-2020). We sequenced 137 representative isolates for core genome multilocus sequence typing, resistome and virulome analysis. For the 36,612 invasive S. aureus isolates, methicillin resistance decreased from 26.4% in 2004 to 22.4% in 2020. Erythromycin resistance in methicillin-susceptible S. aureus (MSSA) increased from 13.6% in 2004 to 28.9% in 2020 (p < 0.001); however, it decreased from 68.7 to 61.8% (p < 0.0001) in methicillin-resistant S. aureus (MRSA). Total consumption of MLSB antibiotics increased from 2.72 defined daily doses per 1,000 inhabitants per day (DID) in 2014 to 3.24 DID in 2016. By WGS, the macrolide resistance genes detected were erm (59.8%), msrA (46%), and mphC (45.2%). The erm genes were more prevalent in MSSA (44/57, 77.2%) than in MRSA (38/80, 47.5%). Most of the erm genes identified in MSSA after 2013 differed from the predominant ermC gene (17/22, 77.3%), largely because ermT was significantly associated with MSSA after 2013 (11/29, 37.9%). All 13 ermT isolates in this study, except one, belonged to ST398 and came from 10 hospitals and six Spanish provinces. The significant increase in erythromycin resistance in blood MSSA correlated with the consumption of the MLSB antibiotics in Spain. These preliminary data seem support the hypothesis that the human ST398 MSSA clade with ermT-mediated resistance to erythromycin may be involved in this trend.

Developing an antibiogram for empiric antibiotic prescribing for adult non-spinal orthopaedic infections in a developing world setting

PurposeEmpiric antibiotic strategies in the treatment of fracture-related infections, chronic osteomyelitis, prosthetic joint infection, and septic arthritis should be based on local microbiological antibiograms. This study aims to describe the microbiology and review the antibiogram profiles of bacterial isolates from patients undergoing surgical treatment for non-spinal orthopaedic infections, to identify the most appropriate empiric antibiotic strategy.MethodsA retrospective review was performed of all cases of non-spinal orthopaedic infections treated surgically from 1 January 2018 to 31 December 2018. The National Health Laboratory Service microbiology database was used to identify all intra-operative microbiological specimens obtained from orthopaedic patients, and data were correlated with the orthopaedic surgical database. Cases were divided into fracture-related infections, chronic osteomyelitis, prosthetic joint infection, and septic arthritis. Antibiotic susceptibility data were used to predict the efficacy of different empiric antibiotic regimens.ResultsA total of 107 cases were included in the study; 184 organisms were cultured. Overall, the most common organism cultured was Staphylococcus aureus (25%) followed by Acinetobacter baumannii (9%), Enterococcus faecalis (7%) and Enterobacter cloacae (5%). Across all categories the oral antibiotic combination with the highest effectiveness (81%) would have been a combination of co-trimoxazole, ciprofloxacin and amoxicillin. The most effective intravenous antibiotic combination would have been either piperacillin–tazobactam, amikacin and vancomycin or meropenem and vancomycin; 90% of tested isolates were susceptible to either of these combinations.ConclusionAntibiogram profiles can serve to guide to empiric antibiotic choice in the management of different categories of non-spinal orthopaedic infections.

Refractory Helicobacter pylori infection in Australia: updated multicentre antimicrobial resistance.

Helicobacter pylori infection is responsible for considerable morbidity and mortality worldwide and eradication rates are falling globally because of increasing antimicrobial resistance. However, there is a paucity of local data to guide the choice of eradication therapy in Australia. This study aimed to evaluate current Australian rates of H. pylori antibiotic resistance in patients who had failed prior eradication therapy. A retrospective analysis of routine culture and antibiotic susceptibility data from two pathology laboratories servicing multiple tertiary referral hospitals in Western Australia (WA) and South Australia (SA), between 2018 and 2022, was performed. Rates of antimicrobial resistance and prevalence of multiresistant isolates in both SA and WA were calculated and comparison of temporal trends and differences between the two states was conducted. A total of 796 H. pylori isolates revealed a clarithromycin resistance rate of 82%, metronidazole 68%, amoxicillin 4.4% and tetracycline 0.5%. Resistance to levofloxacin was observed in 22% and rifampicin 14%. Rates of resistance to clarithromycin were lower in SA compared with WA (incidence rate ratio [IRR]: 0.69, P = 0.0001). Multiresistant isolates were discovered in 63% of patients, with lower rates in SA compared with WA (IRR: 0.74, P = 0.002). This first multicentre, multistate study of H. pylori resistance in Australian patients exposed to prior therapy demonstrated high rates of antimicrobial resistance, including levofloxacin (>20%). This raises concern about recommending levofloxacin in empirical second-line therapies. Increased monitoring and awareness of current H. pylori resistance rates in Australia are needed to guide local eradication practices.

Urinary Tract Infections in Children: Clinical and Antibiotic Susceptibility Data from a Tertiary Care Hospital

Aim: Urinary tract infections (UTIs) are among the most common bacterial infections in children.&#x0D; Empirical antibiotic treatment is recommended until the antibiogram reports of urine culture are&#x0D; available. It is essential to initiate local UTI agents and their antimicrobial susceptibility patterns in&#x0D; specific geographical regions to choose the best empirical antibiotics. The current study aimed to&#x0D; determine causative microorganisms and antibiotic resistance patterns in children diagnosed with UTI.&#x0D; Material and Methods: The study was carried out retrospectively with 216 children diagnosed with&#x0D; UTIs for the first time. The patients were categorized into two groups according to age (≤1 year and &gt;1&#x0D; year). Demographic data, presenting symptoms, imaging findings, and urine and culture analysis results&#x0D; were collected and compared between these two groups.&#x0D; Results: Cefazolin and nitrofurantoin use may be preferred in the empirical treatment of UTIs caused&#x0D; by Escherichia coli and Enterococcus spp. Additionally, amoxicillin/clavulanate was recommended in&#x0D; the empirical therapy of UTIs caused by Enterococcus spp., Klebsiella spp., and Proteus spp. The&#x0D; trimethoprim-sulfamethoxazole and nitrofurantoin resistance of E. coli was found to be statistically&#x0D; significantly higher in the ≤1 year group (p=0.03 and p=0.01, respectively), while the nitrofurantoin&#x0D; resistance of Klebsiella was statistically significantly higher in the &gt;1 year group (p=0.01). The gentamicin&#x0D; resistance of Klebsiella spp. was statistically significantly higher in the ≤1 year group (p=0.03).&#x0D; Conclusion: It is important to detect regional antibiotic resistance patterns to manage UTIs and minimize&#x0D; related complications. Antibiotic susceptibility studies are necessary to reduce improper antibiotic use&#x0D; and resistance rates of antibiotics.

Early-life surface colonization with multi-drug resistant organisms in the neonatal intensive care unit

ObjectivesIn this study, we aim to describe the patterns of early-life surface colonization with multi-drug resistant (MDR) organisms (MDROs) among newborns admitted to the neonatal intensive care unit (NICU). MethodsWe conducted a retrospective descriptive study of infants with culture-positive external ear surface swabs performed immediately after admission to our NICU from January 1, 2017 – December 31, 2021. Clinical characteristics, culture and antibiotic susceptibility data were extracted from the department data collection and hospital electronic databases. ResultsA total of 314 infants were included - median 34 weeks gestation (interquartile range [IQR] 30, 38) and median birthweight 2147 g (IQR 1470, 2875). Of the 379 bacterial isolates obtained, 259 (68.3%) were gram-negative with Escherichia coli (149/379, 39.3%) and Klebsiella spp (57/379, 15.0%) the most common gram-negatives isolated. MDROs accounted for 17.4% (45/259) of gram-negative isolates. There was no methicillin-resistant Staphylococcus aureus (0/22 isolates) or vancomycin-resistant Enterococcus (0/68) detected among isolates tested. A total of 27 (8.6%) infants developed bacteremia, of which 21/27 (77.8%) had concordant bacteria isolated from surface cultures, with identical resistance patterns, and 4/21 (19.0%) isolates were MDROs. ConclusionIn our setting where gram-negative bacteria accounted for a high proportion of initial colonization, MDR gram-negatives accounted for up to 17% of colonizing gram-negative bacteria detected.

Microbiological spectrum and antibiotic susceptibility patterns of non-viral conjunctivitis over 16years at a tertiary eye care center in Southern India.

To determine the trends in the microbial spectrum and antibacterial susceptibility patterns of non-viral conjunctivitis over 16years. Microbiology data were reviewed from 2006-2021 for all the patients with clinically and culture-proven infectious conjunctivitis. Conjunctival swabs and/or conjunctival scrapings were collected for microbiological workup, and the demographic and antibiotic susceptibility data were extracted from the EMR (Electronic Medical Record). For statistical analysis, χ2-test was performed. Of the 1711 patients, 814 (47.57%) were culture positive and 897 (52.43%) were culture negative. Of the total culture-proven conjunctivitis cases, 775/814 (95.20%) were bacteria, and 39/814 (4.80%) were fungi. Among these bacterial isolates, 75.74% were gram-positive bacteria, while 24.26% were gram negative. The predominant gram-positive pathogens isolated were S. epidermidis (16.7%), S. aureus (17.9%) (p < 0.05), and S. pneumoniae (18.2%), while Haemophilus spp. (36.2%) (p < 0.05) was the most often isolated gram-negative bacteria (36.2%), and Aspergillus spp. was the most commonly isolated fungus (50%). The susceptibility of gram-positive bacteria to cefazoline increased from 90.46 to 98% (p = 0.01), whereas the susceptibility for gatifloxacin decreased in both gram-positive (81-41%; p < 0.0001) and gram-negative bacteria (73-58%; p = 0.02). Increasing resistance of ocular isolates to mainstay antibiotics is a concern, and this data can assist healthcare practitioners in making informed choices regarding the treatment of ocular infections with ophthalmic antibiotics.

The first case of Janibacter bacteremia in pregnancy: A case report and review

Clinical infection with Janibacter species is an infrequently reported event. There are a small number of cases of patients with Janibacter bacteremia recognized to date. We report the first case of Janibacter bacteremia in a pregnant woman. The bacteremia was associated with pneumonia. Such cases can be difficult to manage due to the lack of antibiotic susceptibility data for these bacteria. We also report susceptibility data for the Janibacter hoylei that was isolated in our patient. This case demonstrates that J. hoylei can be a pathogen in otherwise immunocompetent pregnant women.

A geospatial approach to identify patterns of antibiotic susceptibility at a neighborhood level in Wisconsin, United States

The global threat of antimicrobial resistance (AMR) varies regionally. This study explores whether geospatial analysis and data visualization methods detect both clinically and statistically significant variations in antibiotic susceptibility rates at a neighborhood level. This observational multicenter geospatial study collected 10 years of patient-level antibiotic susceptibility data and patient addresses from three regionally distinct Wisconsin health systems (UW Health, Fort HealthCare, Marshfield Clinic Health System [MCHS]). We included the initial Escherichia coli isolate per patient per year per sample source with a patient address in Wisconsin (N = 100,176). Isolates from U.S. Census Block Groups with less than 30 isolates were excluded (n = 13,709), resulting in 86,467 E. coli isolates. The primary study outcomes were the results of Moran’s I spatial autocorrelation analyses to quantify antibiotic susceptibility as spatially dispersed, randomly distributed, or clustered by a range of − 1 to + 1, and the detection of statistically significant local hot (high susceptibility) and cold spots (low susceptibility) for variations in antibiotic susceptibility by U.S. Census Block Group. UW Health isolates collected represented greater isolate geographic density (n = 36,279 E. coli, 389 = blocks, 2009–2018), compared to Fort HealthCare (n = 5110 isolates, 48 = blocks, 2012–2018) and MCHS (45,078 isolates, 480 blocks, 2009–2018). Choropleth maps enabled a spatial AMR data visualization. A positive spatially-clustered pattern was identified from the UW Health data for ciprofloxacin (Moran’s I = 0.096, p = 0.005) and trimethoprim/sulfamethoxazole susceptibility (Moran’s I = 0.180, p < 0.001). Fort HealthCare and MCHS distributions were likely random. At the local level, we identified hot and cold spots at all three health systems (90%, 95%, and 99% CIs). AMR spatial clustering was observed in urban areas but not rural areas. Unique identification of AMR hot spots at the Block Group level provides a foundation for future analyses and hypotheses. Clinically meaningful differences in AMR could inform clinical decision support tools and warrants further investigation for informing therapy options.

Analysis of the structure of bacteremia and sensitivity to antibiotics of microorganisms isolated in intensive care units in an emergency hospital in the period from 2003 to 2021: a retrospective observational study

INTRODUCTION: Creation of protocols for effective empiric antimicrobial therapy is impossible without the analysis of current antibiotic susceptibility data. OBJECTIVE: Analysis of changes in the etiological significance of the leading pathogens of bacteremia in the ICU (intensive care unit) in the period from 2003 to 2021, and their sensitivity to antibiotics; study of the types of carbapenemases in the most relevant pathogens — Klebsiella pneumoniae and Acinetobacter baumannii. MATERIALS AND METHODS: The analysis included all microorganisms isolated from the blood of patients who were in the medical 12-bed ICU in the emergency hospital of Moscow in the period from 2003 to 2021. Identification of microorganisms and determination of antibiotic sensitivity were carried out with an automatic PHOENIX analyzer and a standardized disco diffusion method. Detection of carbapenemases was carried out by PCR (polymerase chain reaction). RESULTS: In the period from 2003 to 2021, 17 034 blood samples were examined, from which 6372 microorganisms were isolated. During this period, the proportion of Gram-negative microorganisms increased from 21.0 to 52.8 %, mainly due to K. pneumoniae from 1.0 to 24.5 % and A. baumannii from 0 to 9.1 %. The resistance of these microorganisms to carbapenems increased significantly from 2008 to 2021: K. pneumoniae from 2.3 % to 70.3 %, A. baumannii — from 7.5 to 99.5 %. K. pneumoniae produced the following types of carbapenemases: OXA-48 (73.8 %), KPC (6.2 %), NDM 1.5 %, NDM + OXA-48 (15.4 %), KPC + OXA-48 (3.1 %). All A. baumannii strains produced OXA-40 type carbapenemase. OXA-48 carbapenemase producers were resistant to colistin and tigecycline in 14.6 and 44.8 %, and to ceftazidime/avibactam in 4.2 %. CONCLUSIONS: The increased level of antimicrobial resistance in recent years among Gram-negative microorganisms isolated from blood is a very significant problem in the ICU. Most K. pneumoniae strains are characterized as multi-drug resistant, about 10 % of the strains were categorized as extremely-drug resistant (XDR) or pan-drug resistant. All strains of A. baumannii belong to the category of XDR.

Determination of antibiotic resistance rates of Escherichia coli and Klebsiella pneumoniae isolates, which are the causative agents of urinary tract infection in pregnant women

Aim: Urinary tract infections are common infections during pregnancy. Infections seen during pregnancy have a spectrum ranging from asymptomatic bacteriuria to cystitis, pyelonephritis and, urosepsis. In this study, it was aimed to determine the antibiotic resistance rates of Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) isolates isolated from urinary cultures of pregnant women who applied to the Ankara Training and Research Hospital. &#x0D; Material and Method: The identification and antibiotic susceptibility of E. coli and K. pneumoniae isolates isolated from urinary samples of pregnant women who applied to the Ankara Training and Research Hospital between January 2021 and December 2022 were investigated with VITEK-2 (Biomerioux, France) fully automated system, and the presence of extended-spectrum beta-lactamase (ESBL) was investigated by combined disc diffusion method. The obtained data were analysed retrospectively.&#x0D; Results: Bacterial growth was detected in 1090 (1.2%) out of a total of 8923 urine samples over a two-year period. 480 (4.4%) of the microbial agents reproducing in urine culture were E. coli and 105 (0.96%) were K. pneumoniae. The rate of extended-spectrum beta-lactamase (ESBL) in E. coli strains was 16.04% (77/480), and the rate of ESBL in K. pneumoniae strains was 20.9% (22/105). Resistance rates of amoxicillin-clavulanic acid, ceftriaxone, phosphomycin, ciprofloxacin, piperacillin-tazobactam, nitrofurantoin, imipenem, meropenem, ertapenem in ESBL negative E. coli strains were 15.9%, 8.82%, 20%, 11.1%, 5.88%, 0%, 0%, 0% and 0%, respectively. Resistance rates of amoxicillin-clavulanic acid, ceftriaxone, phosphomycin, ciprofloxacin, piperacillin-tazobactam, nitrofurantoin, imipenem, meropenem, ertapenem in ESBL positive E. coli strains were determined as 66.5%, 100%, 2.2%, 33.8%, 11.5%, 0%, 0%, 0% and, 0%, respectively. Resistance rates of amoxicillin-clavulanic acid, ceftriaxone, phosphomycin, ciprofloxacin, piperacillin-tazobactam, nitrofurantoin, imipenem, meropenem, ertapenem in ESBL negative K. pneumoniae strains were 53%, 100%, 12.5%, 28.5%, 2.2%, 3.5%, 0%, 0% and, 4.5%, respectively. Resistance rates of amoxicillin-clavulanic acid, ceftriaxone, phosphomycin, nitrofurantoin, ciprofloxacin, piperacillin-tazobactam, imipenem, meropenem, ertapenem in ESBL positive K. pneumoniae strains were 62.5%, 100%, 12.5%, 35%, 28.5%, 22.7%, 0%, 0% and, 4.5%, respectively.&#x0D; Conclusion: According to the antibiotic susceptibility data in our hospital, phosphomycin or carbapenems may be preferred due to the low resistance rate in the empirical treatment of E. coli-related urinary tract infections in pregnant women. In the treatment of urinary tract infections due to K. pneumoniae, phosphomycin, piperacillin-tazobactam or carbapenems may be preferred due to low resistance rates.

Can non-typeable Haemophilus influenzae carriage surveillance data infer antimicrobial resistance associated with otitis media?

In remote communities of the Northern Territory, Australia, children experience high rates of otitis media (OM), commonly caused by non-typeable Haemophilus influenzae (NTHi). Few data exist on antibiotic susceptibility of NTHi from OM. To determine whether population-level nasopharyngeal NTHi antibiotic susceptibility data could inform antibiotic treatment for OM. NTHi isolates (n=92) collected from ear discharge between 2003 and 2013 were selected to time- and age-match NTHi isolates from the nasopharyngeal carriage (n=95). Antimicrobial susceptibility were tested. Phylogenomic trees and a genome-wide association study (GWAS) were performed to determine the similarity of nasopharyngeal and ear isolates at a population level. Among 174 NTHi isolates available for antimicrobial susceptibility testing, 10.3% (18/174) were resistant to ampicillin and 9.2% (16/174) were resistant to trimethoprim-sulfamethoxazole. Small numbers of isolates (≤3) were resistant to tetracycline, chloramphenicol, or amoxicillin-clavulanic acid. There was no statistical difference in the proportion of ampicillin-resistant (P=0.11) or trimethoprim-sulfamethoxazole-resistant isolates (P=0.70) between ear discharge and nasopharynx-derived NTHi isolates. Three multi-drug resistant NTHi isolates were identified. Phylogenomic trees showed no clustering of 187 Haemophilus influenzae isolates based on anatomical niche (nasopharynx or ear discharge), and no genetic variations that distinguished NTHi derived from ear discharge and nasopharyngeal carriage were evident in the GWAS. In this population-level study, nasopharyngeal and ear discharge isolates did not represent distinct microbial populations. These results support tracking of population-level nasopharyngeal NTHi antibiotic resistance patterns to inform clinical management of OM in this population.