Effect of prior receipt of antibiotics on the pathogen distribution and antibiotic resistance profile of key Gram-negative pathogens among patients with hospital-onset urinary tract infections

Investigating Urinary Pathogens and Their Antibiotic Resistance: A Cross-Sectional Urine Culture Study

INTRODUCTION

Urinary tract infections (UTIs) are among the most prevalent infectious diseases. Females are more affected than males. The primary culprit is Escherichia coli. Multiple research investigations have documented widespread antimicrobial resistance in uropathogens, sparking global concerns, especially regarding the rise of multidrug resistance (MDR).

METHODOLOGY

This cross-sectional study was conducted from December 2023 to March 2024. A non-probability purposive sampling technique was employed to select participants, and informed consent was obtained from them. Data were extracted from the culture and sensitivity reports of these patients. The collected data were meticulously entered into IBM SPSS Statistics for Windows, Version 21 (IBM Corp., Armonk, NY). The findings were then presented using a blend of percentages and numerical figures, offering a clear and concise representation of the data.

RESULTS

Our study of 313 participants showed a higher prevalence of UTIs in females (219, 70%) compared to males (94, 30%). E. coli and Citrobacter were the predominant pathogens, with E. coli and Citrobacter more common in females, while Enterobacter and Staphylococcus were more prevalent in males. Antibiogram analysis revealed sensitivities to specific drugs like nitrofurantoin and meropenem, while resistance was observed against others, including polymyxin B and ampicillin. These findings stress the need for tailored UTI treatment approaches.

CONCLUSIONS

In conclusion, our research highlights a concerning trend of escalating antibiotic resistance among Pakistani patients with UTIs. Tobramycin B, ticarcillin-clavulanic acid, ampicillin, and clotrimazole exhibited the highest resistance rates, while imipenem, meropenem, nitrofurantoin, sulfonamides, and tigecycline demonstrated notable sensitivity. These findings emphasize the urgent need for the exploration of alternative treatment options to combat rising resistance levels effectively.

Clinical Risk Scores to Predict Nonsusceptibility to Trimethoprim-Sulfamethoxazole, Fluoroquinolone, Nitrofurantoin, and Third-Generation Cephalosporin Among Adult Outpatient Episodes of Complicated Urinary Tract Infection

Background

Clinical risk scores were developed to estimate the risk of adult outpatients having a complicated urinary tract infection (cUTI) that was nonsusceptible to trimethoprim-sulfamethoxazole (TMP-SMX), fluoroquinolone, nitrofurantoin, or third-generation cephalosporin (3-GC) based on variables available on clinical presentation.

Methods

A retrospective cohort study (1 December 2017-31 December 2020) was performed among adult members of Kaiser Permanente Southern California with an outpatient cUTI. Separate risk scores were developed for TMP-SMX, fluoroquinolone, nitrofurantoin, and 3-GC. The models were translated into risk scores to quantify the likelihood of nonsusceptibility based on the presence of final model covariates in a given cUTI outpatient.

Results

A total of 30 450 cUTIs (26 326 patients) met the study criteria. Rates of nonsusceptibility to TMP-SMX, fluoroquinolone, nitrofurantoin, and 3-GC were 37%, 20%, 27%, and 24%, respectively. Receipt of prior antibiotics was the most important predictor across all models. The risk of nonsusceptibility in the TMP-SMX model exceeded 20% in the absence of any risk factors, suggesting that empiric use of TMP-SMX may not be advisable. For fluoroquinolone, nitrofurantoin, and 3-GC, clinical risk scores of 10, 7, and 11 predicted a ≥20% estimated probability of nonsusceptibility in the models that included cumulative number of prior antibiotics at model entry. This finding suggests that caution should be used when considering these agents empirically in patients who have several risk factors present in a given model at presentation.

Conclusions

We developed high-performing parsimonious risk scores to facilitate empiric treatment selection for adult outpatients with cUTIs in the critical period between infection presentation and availability of susceptibility results.

Resistance pattern of infected chronic wound isolates and factors associated with bacterial resistance to third generation cephalosporins at Mbarara Regional Referral Hospital, Uganda

BACKGROUND

The objectives of this study were; (I) to determine the proportion of pathogens isolated from patients with infected chronic wounds in the surgical ward of MRRH that are resistant to the third-generation cephalosporins and (II) to determine the factors associated with resistance to third-generation cephalosporins in the surgical ward of MRRH.

METHOD(S)

This study was a descriptive analytical survey of bacterial isolates from infected chronic wounds among patients admitted in the surgical ward of MRRH, Uganda. Seventy five (75) study participants were recruited in the study using convenient sampling technique. Bacterial culture and identification was performed using standard microbiology laboratory procedures whereas broth microdilution method was used to establish the susceptibility of the identified pathogens. Data for objective one (1) was summarized as proportions while the categorized variables were analyzed using logistic regression to determine whether they were associated with the resistance patterns. The level of significance was preset at 5% and p-values less than 0.05 were considered statistically significant.

RESULTS

Generally, all isolates had complete susceptibility (100%) to Cefoperazone+Sulbactam 2g except 7.1% of proteus spp that were resistant. Of all the bacterial isolates studied, Staphylococcus aureus, Enterobacter agglomerans, providencia spp and pseudomonas earuginosa had complete resistance (100%) to Cefopodoxime 200mg while providencia spp and pseudomomas earuginosa had complete resistance (100%) to Cefixime 400mg and cefotaxime 1g. Finally, higher odds of bacterial resistance to more 2 brands of the third generation cephalosporins were observed among participants who had prior exposure to the third generation cephalosporins (OR, 2.22, 95% CI, 0.80-6.14), comorbidities (OR, 1.76, 95% CI, 0.62-4.96) and those who had more than two hospitalizations in a year (OR, 1.39, 95% CI 0.46-4.25). However, multivariate logistic regression was not performed since no factor was significantly associated with resistance to more than two brands of third generation cephalosporins (p >0.05).

CONCLUSION

This study found that cefixime and cefpodoixme had high rates of resistance and should not be used in routine management of infected chronic wounds. In addition, the factors investigated in this study were not significantly associated with bacterial resistance to more than two brands of third generation cephalosporins.

Global Prevalence of Nosocomial Multidrug-Resistant Klebsiella pneumoniae: A Systematic Review and Meta-Analysis

The emergence of nosocomial multidrug-resistant Klebsiella pneumoniae is an escalating public health threat worldwide. The prevalence of nosocomial infections due to K. pneumoniae was recorded up to 10%. In this systematic review and meta-analysis, which were conducted according to the guidelines of Preferred Reporting Items for Systematic Review and Meta-Analysis, 1092 articles were screened from four databases of which 47 studies fulfilled the selected criteria. By performing a random-effect model, the pooled prevalence of nosocomial multidrug-resistant K. pneumoniae was estimated at 32.8% (95% CI, 23.6-43.6), with high heterogeneity (I2 98.29%, p-value < 0.001). The estimated prevalence of this pathogen and a few related studies were discussed, raising awareness of the spread of multidrug-resistant K. pneumoniae in the healthcare setting. The emergence of nosocomial multidrug-resistant K. pneumoniae is expected to increase globally in the future, and the best treatments for treating and preventing this pathogen should be acknowledged by healthcare staff.

Antibacterial and Antifungal Activities of the Leaf Exudate of Aloe megalacantha Baker

Infectious diseases caused by fungi and bacteria are among the major causes of illness and death worldwide. This is mainly implicated by the antimicrobial resistance of the current treatment regimens. Since plant products are house stores of bioactive compounds, it is essential to screen plant-based antimicrobials to come up with novel medicines that counter the grave consequences of antimicrobial resistance. In the folk medicine of Ethiopia, Aloe megalacantha is used for the treatment of wound, dandruff, malaria, diabetes, impotence, colon cleansing, amoeba, ascariasis, abdominal pain, urine retention, snake bite, and evil eye. Hence, the present study was aimed to evaluate the antibacterial and antifungal effects of the leaf exudate of Aloe megalacantha. Agar well diffusion was employed to determine the antibacterial and antifungal effects. Six bacterial strains, namely, S. aureus (standard), S. aureus (clinical isolate), E. coli ATCC 25922 (standard), E. coli (clinical isolate), K. pneumoniae (standard), and P. aeruginosa ATCC 27853 (standard), and four fungal strains such as C. albicans, C. glabrata, C. tropicalis, and C. krusei were studied. The leaf exudate showed the highest activity against C. krusei with an average zone diameter of 22.49 ± 0.47 mm at 400 mg/mL. Among the bacterial species, S. aureus ATCC 29213 (standard) was the most sensitive with an average zone of diameter of 16.63 ± 0.12 mm at 200 mg/mL. Thus, the present findings support the folklore use of Aloe megalacantha for the treatment of different microbial infections.

Effect of prior receipt of antibiotics on the pathogen distribution: a retrospective observational cohort study on 27,792 patients

Background

There have been no systematic studies of microbiological differences before and after antibiotics treatment. The aim of this study was to evaluate the effect of prior receipt of antibiotics on the microorganism distribution.

Methods

A retrospective, observational cohort study was conducted in a 3200-bed tertiary, referral, teaching hospital in eastern China. During a 2-year period, all hospitalized patients treated with antimicrobial agents were enrolled in this study. Among 48,692 patients evaluated, the 27,792 (57.1%) who were sampled within 2 days before or after administration of the first dose of antimicrobial agents were included. Distribution of clinical specimens and the microorganism were compared between before and after antibiotic drug treatment groups.

Results

Compared to specimens taken after antibiotics exposure, specimens taken before antibiotics exposure had a higher proportion of blood and urine specimens and a higher culture positive rate (all P < 0.001). Higher percentages of Staphylococcus aureus (9.9% vs. 8.5%, P = 0.041), non-fermenting bacteria (27.7% vs. 19.9%, P < 0.001), and fungi (8.4% vs. 4.0%, P < 0.001) were isolated from the group after antibiotics exposure, while the percentages of Streptococcus spp. (4.8% vs. 2.7%, P < 0.001), Haemophilus influenzae (2.3% vs. 0.8%, P < 0.001), and Moraxella catarrhalis (0.7% vs. 0.1%, P < 0.001) were higher in the group before antibiotics exposure. Further analysis found significant differences of microbes derived from respiratory secretions, blood or urine samples. We found, after antibiotics exposure, the separation rate of non-fermenting bacteria was significantly increased (all P < 0.05), and the separation rate of Candida spp. was higher, with statistical significance in airway secretion and urine samples (both P < 0.05), but the separation rate of Staphylococcus aureus among the three groups was not affected by antibiotics. In addition, the isolation rate of Streptococcus spp. in blood and urine samples decreased significantly (both P < 0.05) after antibiotics exposure. Interestingly, no statistical difference was found for microbes isolated from body fluid specimens between the two groups.

Conclusions

The outcome revealed that antibiotic-insensitive organisms such as non-fermentative bacteria and fungi were more frequently isolated after antibiotics exposure. However, this trend might be specimen dependent and was not obvious in body fluid specimens.

Surgical Antibiotic Prophylaxis and Risk for Postoperative Antibiotic-Resistant Infections

BACKGROUND

Antibiotic-resistant infections have high rates of morbidity and mortality, and exposure to antibiotics is the crucial risk factor for development of antibiotic resistance. If surgical antibiotic prophylaxis (SAP) increases risk for antibiotic-resistant infections, prophylaxis may cause net harm, even if it decreases overall infection rates.

STUDY DESIGN

This retrospective cohort study included adults who underwent elective surgical procedures and developed infections within 30 postoperative days. Procedures from multiple disciplines were included if SAP was considered discretionary by current guidelines. Postoperative antibiotic-resistant infections were defined as positive culture results from any site within 30 postoperative days, showing intermediate or nonsusceptibility across 1 or more antibiotic classes. Surgical antibiotic prophylaxis included use of antibiotics within any class and at any dose from 1 hour before first incision until the end of the operation.

RESULTS

Among 689 adults with postoperative infections, 338 (49%) had postoperative resistant infections. Use of SAP was not associated with postoperative antibiotic-resistant infections (odds ratio [OR] 0.99; 95% CI 0.67 to 1.46). This result remained robust when the SAP definition was extended to antibiotics given within 4 hours before first incision (OR 0.94; 95% CI 0.63 to 1.40) and when the follow-up window was narrowed to 14 days (OR 0.82; 95% CI 0.50 to 1.34). Previous antibiotic-resistant infections were associated with risk for postoperative antibiotic-resistant infections (OR 1.81; 95% CI 1.16 to 2.83).

CONCLUSIONS

Use of SAP was not associated with risk for postoperative antibiotic-resistant infections in a large cohort of patients with postoperative infections. This provides important reassurance regarding use of surgical antibiotic prophylaxis.