Differences In Resistance Patterns Research Articles

Prevalence of Methicillin-Resistant Staphylococcus aureus in Saudi Arabia: A Systematic Review and Meta-Analysis.

Methicillin-resistant Staphylococcus aureus (MRSA) is a public health concern due to its capacity to build biofilms and acquire drug resistance. The purpose of this systematic review and meta-analysis is to analyze the prevalence of MRSA in Saudi Arabia and look into its resistance to various antibiotics. A comprehensive systematic search for key scientific databases from 1990 to June 2024 was carried out using predetermined keywords. MRSA prevalence rates were examined in studies that met the inclusion criteria, with an emphasis on clinical and community settings. The MedCalc software was used to conduct statistical analysis. The meta-analysis includes 24 trials with 16,646 samples. The overall prevalence of MRSA was discovered to be 8.601% (fixed effects) and 17.027% (random effects), with confidence ranges of 8.179-9.037 and 12.503-22.091, respectively. The research showed substantial antibiotic resistance, notably to β-lactams, whereas vancomycin remained effective against most MRSA strains. The data show an alarming incidence of MRSA in hospital settings, as well as significant resistance to numerous antibiotic classes, emphasizing the importance of improved infection control strategies and sensible antibiotic usage. Geographic differences in resistance patterns point to regional factors impacting MRSA spread and resistance. This analysis highlights the significant prevalence of MRSA in Saudi clinical settings, as well as the complexities of its resistance profiles. Continued observation and study into the genetic mechanisms that contribute to resistance are critical for successful MRSA infection management and prevention.

Detection of Macrolide and/or Fluoroquinolone Resistance Genes in Mycoplasma genitalium Strains Isolated from Men in the Northwest Region of Croatia in 2018-2023.

Mycoplasma genitalium (M. genitalium) poses a significant public health challenge due to its association with non-gonococcal urethritis (particularly in men) and antimicrobial resistance. However, despite the prevalence of M. genitalium infections and the rise in resistance rates, routine testing and surveillance remain limited. This is the first study from Croatia that aimed to assess the prevalence and trends of resistance in M. genitalium strains isolated from male individuals by detecting macrolide and fluoroquinolone resistance genes. The study also aimed to explore the factors associated with resistance and changes in resistance patterns over time. Urine samples collected from male individuals in the Zagreb County and northwest region of Croatia between 2018 and 2023 were tested for M. genitalium with the use of molecular methods. Positive samples were subjected to DNA extraction and multiplex tandem polymerase chain reaction (MT-PCR) targeting genetic mutations associated with macrolide (23S rRNA gene) and fluoroquinolone (parC gene) resistance. Of the 8073 urine samples tested from 6480 male individuals (and following the exclusion of repeated specimens), we found that the prevalence of M. genitalium infection was 2.2%. Macrolide resistance was observed in 60.4% of strains, while fluoroquinolone resistance was found in 19.2%. Co-resistance to both antibiotics was present in 18.2% of cases. A statistically significant increase in fluoroquinolone resistance was noted over the study period (p = 0.010), but this was not evident for azithromycin resistance (p = 0.165). There were no statistically significant differences in resistance patterns between age groups, whereas re-testing of patients revealed dynamic changes in resistance profiles over time. The high burden of macrolide resistance and increasing fluoroquinolone resistance underscore the urgent need for comprehensive resistance testing and surveillance programs. The implementation of resistance-guided treatment strategies, along with enhanced access to molecular diagnostics, is pivotal for effectively managing M. genitalium infections.

Estimation of antimicrobial resistance of Mycoplasma genitalium, Belgium, 2022.

BackgroundAntimicrobial resistance (AMR) of Mycoplasma genitalium (MG) is a growing concern worldwide and surveillance is needed. In Belgium, samples are sent to the National Reference Centre of Sexually Transmitted Infections (NRC-STI) on a voluntary basis and representative or robust national AMR data are lacking.AimWe aimed to estimate the occurrence of resistant MG in Belgium.MethodsBetween July and November 2022, frozen remnants of MG-positive samples from 21 Belgian laboratories were analysed at the NRC-STI. Macrolide and fluoroquinolone resistance-associated mutations (RAMs) were assessed using Sanger sequencing of the 23SrRNA and parC gene. Differences in resistance patterns were correlated with surveillance methodology, socio-demographic and behavioural variables via Fisher's exact test and logistic regression analysis.ResultsOf the 244 MG-positive samples received, 232 could be sequenced for macrolide and fluoroquinolone RAMs. Over half of the sequenced samples (55.2%) were resistant to macrolides. All sequenced samples from men who have sex with men (MSM) (24/24) were macrolide-resistant. Fluoroquinolone RAMs were found in 25.9% of the samples and occurrence did not differ between socio-demographic and sexual behaviour characteristics.ConclusionAlthough limited in sample size, our data suggest no additional benefit of testing MG retrieved from MSM for macrolide resistance in Belgium, when making treatment decisions. The lower occurrence of macrolide resistance in other population groups, combined with emergence of fluoroquinolone RAMs support macrolide-resistance testing in these groups. Continued surveillance of resistance in MG in different population groups will be crucial to confirm our findings and to guide national testing and treatment strategies.

Comparison of antimicrobial resistance among Salmonella enterica serovars isolated from Canadian turkey flocks, 2013 to 2021

The emergence of antimicrobial resistance (AMR) in Salmonella from turkeys has raised a food safety concern in Canada as certain serovars have been implicated in human salmonellosis outbreaks in recent years. While several studies evaluated AMR in broiler chickens in Canada, there are limited studies that assess AMR in turkey flocks. This study analyzed data collected between 2013 and 2021 by the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) farm turkey surveillance program to determine the prevalence of AMR and differences in resistance patterns among Salmonella serovars recovered from turkey flocks. Salmonella isolates were tested for susceptibility to 14 antimicrobials using a microbroth dilution method. Hierarchical clustering dendrograms were constructed to compare the individual AMR status of Salmonella serovars. Differences in the probability of resistance between Salmonella serovars were determined using generalized estimating equation logistic regression models to account for farm-level clustering. Of the 1,367 Salmonella isolates detected, 55.3% were resistant to at least one antimicrobial and 25.3% were multidrug resistant (MDR) (resistant to ≥3 antimicrobial classes). The Salmonella isolates exhibited high resistance to tetracycline (43.3%), streptomycin (47.2%), and sulfisoxazole (29.1%). The 3 most frequently occurring serovars were S. Uganda (22.9%), S. Hadar (13.5%), and S. Reading (12.0%). Streptomycin-sulfisoxazole-tetracycline (n=204) was the most frequent MDR pattern identified. Heatmaps showed that S. Reading exhibited coresistance to the quinolone class antimicrobials, ciprofloxacin, and nalidixic acid; S. Heidelberg to gentamicin and sulfisoxazole; and S. Agona to ampicillin and ceftriaxone. Salmonella Hadar isolates had higher odds of resistance to tetracycline (OR: 152.1, 95% CI: 70.6-327.4) while the probability of being resistant to gentamicin and ampicillin was significantly higher in S. Senftenberg than in all the other serovars. Moreover, S. Uganda had the highest odds of being MDR (OR: 4.7, 95% CI: 3.7-6.1). The high resistance observed warrants a reassessment of the drivers for AMR, including AMU strategies and other production factors. Differences in AMR patterns highlight the need to implement serovar-specific mitigation strategies.

The differences in drug resistance between drug-resistant tuberculosis patients with and without diabetes mellitus in northeast China: a retrospective study

BackgroundDiabetes mellitus (DM) and drug-resistant tuberculosis (DR-TB) are serious global public health problems. This study aimed to explore the differences in drug resistance between DR-TB patients with and without DM. Risk factors for developing multidrug-resistant tuberculosis (MDR-TB) were also investigated among DR-TB patients.MethodsThe patient’s basic demographic, clinical characteristics, and drug susceptibility testing (DST) data were collected from the Chinese Disease Control Information System. Descriptive statistics were used to estimate the frequency and proportion of included variables. Categorical variables were compared using the Chi-square test or Fisher’s exact test. Chi-square tests for trends were used to determine changes and trends in MDR-TB and pre-extensively drug-resistantTB (pre-XDR-TB) patterns over time. Univariate and multivariate logistic regression analysis was used to explore the risk factors of MDR-TB.ResultsCompared with DR-TB patients with DM, DR-TB patients without DM had significantly higher rates of mono-resistant streptomycin (SM) and any resistance to kanamycin (KM), but significantly lower rates of any resistance to protionamide (PTO) and mono-resistance to levofloxacin (LFX), and pre-XDR-TB (P<0.05). The proportion of resistance to other anti-TB drugs was not statistically different between the DR-TB with and without DM. Among DR-TB patients without and with DM, the proportion of patients with MDR-TB and pre-XDR-TB patterns showed a significant downward trend from 2016 to 2021 (P<0.05). Among DR-TB patients without DM, male, previously treated DR-TB cases, and immigration were risk factors for MDR-TB (P<0.05). In DR-TB patients with DM, a negative sputum smear is a risk factor for MDR-TB (P<0.05).ConclusionThere was no statistical difference in resistance patterns between DR-TB with and without DM, except in arbitrary resistance to PTO and KM, mono-resistant SM and LFX, and pre-XDR-TB. Great progress has been made in the prevention and control of MDR-TB and pre-XDR-TB. However, DR-TB patients with and without DM differ in their risk factors for developing MDR-TB.

MP37-06 ANTIMICROBIAL RESISTANCE AND MICROBIAL PATTERNS WITHIN THE CHRONIC PROSTATITIS UROBIOME COMPARED TO ASYMPTOMATIC HEALTHY CONTROLS

You have accessJournal of UrologyCME1 May 2022MP37-06 ANTIMICROBIAL RESISTANCE AND MICROBIAL PATTERNS WITHIN THE CHRONIC PROSTATITIS UROBIOME COMPARED TO ASYMPTOMATIC HEALTHY CONTROLS J. Curtis Nickel, Niccole Diaz, Craig D. Tipton, E. David Crawford, Rick Martin, and Caleb D. Phillips J. Curtis NickelJ. Curtis Nickel More articles by this author , Niccole DiazNiccole Diaz More articles by this author , Craig D. TiptonCraig D. Tipton More articles by this author , E. David CrawfordE. David Crawford More articles by this author , Rick MartinRick Martin More articles by this author , and Caleb D. PhillipsCaleb D. Phillips More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002591.06AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: We present a comparative analysis of the urobiome and its antimicrobial resistance patterns from urine specimens submitted by patients with a clinical diagnosis of chronic prostatitis (CP) and asymptomatic healthy control males. METHODS: The urobiome of 763 subjects with a confirmed physician diagnosis of CP (from data base of 2,397 with CP ICD-10 code) were compared to 92 healthy males with no urological pain or infection. Microbiome and antibiotic resistance gene data were analyzed by NGS and qPCR respectively (MicroGenDx). Differences in each group’s urinary microbiome were investigated from perspectives of compositional differences and antibiotic resistance patterns. RESULTS: In respect to alpha diversity, CP cohort had similar number of species (richness; p=0.1: Fig 1a) but higher Shannon Diversity (richness and evenness of species abundances; F=5, p=0.03, R2=0.6%: Fig 1b) compared to healthy controls. Escherichia coli and Streptococcus agalactiae had significantly higher incidence rate in CP (p = 0. 04) and controls (p = 0.002) respectively. Diagnosis of CP vs controls explained a significant proportion of overall compositional dissimilarity (F=5.51. p=0.001, R2=0.64%). Five species E. coli, C. acnes, K. pneumoniae, C. glucuronolyticum and P. harei had higher average abundance in CP (Fig 1c); present in 50% of CP but only 16% of controls. While frequency of beta lactam (TEM) resistance was higher in CP (p=0.059), no significant differences in resistance patterns were identified for beta latam SHV (p=0.62) aminoglycosides (antia or alph3; p=0.4-0.81), macrolides (emB; p=0.84), methicillin (mecA: p=0.31), quinolones (qnr; p=0.15), tetracycline (tetB or tetM; p=0.37-1.0) or vancomycin (vanA; p=1.0). CONCLUSIONS: CP is associated with significantly different species incidence rates and relative abundances (notably E. coli, K. pneumoniae, C. acnes and C. glucuronolyticum), and with small but statistically significant components of variation in both alpha and beta diversity, but no clinically significant difference in antibiotic resistance patterns compared to healthy controls. The clinical relevance of detecting potential uropathogens with their associated resistance data in CP management needs to be addressed. Source of Funding: MicroGenDx © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e610 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information J. Curtis Nickel More articles by this author Niccole Diaz More articles by this author Craig D. Tipton More articles by this author E. David Crawford More articles by this author Rick Martin More articles by this author Caleb D. Phillips More articles by this author Expand All Advertisement PDF DownloadLoading ...

Antibiotic Resistance in Bacteroides and Prevotella to β-Lactams, Lincosamide and Nitroimidazole: A 20 Year Survey in Lagos, Nigeria

The propensity to develop resistance to antibiotics has accounted for the predominance of Bacteroides and Prevotella in infections due to anaerobic bacteria. The observed differences in resistance pattern across geographical boundaries underscored the timeliness for this study to review data on antibiotic susceptibility and resistance markers amongst Bacteroides and Prevotella to β-lactams, lincosamide and nitroimidazole from selected hospitals in Lagos, Nigeria from 1992-2011. Bacteroides, mostly B. fragilis were the sole anaerobic gram negative bacilli in peritonitis following lower abdominal surgery and bloodstream infections, while Prevotella bivia and P. melaninogenica were more frequent in periodontal abscess, pelvic inflammatory disease and chronic suppurative otitis media. The MIC range and MIC90 of the anaerobes for the antibiotics does not indicate changes in group resistance to antibiotics though isolated cases were recorded. While clear cut patterns were not established for other species, B. fragilis resistance increased for amoxicillin-clavulanic acid from 18.2% in 1992-1996 to 31.4% in 2006-2011 and from 27.3% in 1992-1996 to 34.3% in 2006-2011 for cefoxitin. In contrast, decrease susceptibility was obtained against clindamycin (54.5% in 1992-1996 to 22.9% in 2006-2011). Similarly, 22.7% of B. fragilis strains have the cepA and/or cfxA gene in 1992-1996 compared to 32.1% in 2006-2011. While not all isolates with cepA and/or cfxA genes were resistant to the β-lactams, all isolates carrying the ermF or nim genes were resistant to the lincosamide (clindamycin) or nitroimidazole (metronidazole) respectively. The presence of antibiotics resistance genes can be used in tracking resistance amongst species of Bacteroides and Prevotella. With emerging new technologies, gene screening may prove more effective and reliable for therapeutic decisions for anaerobic bacterial infections especially since the genes can be screened from the infective exudates. This will eliminate the need for culture and antibiotic susceptibility testing for this group of fastidious microorganisms.

Antibiotic susceptibility of human gut-derived facultative anaerobic bacteria is different under aerobic versus anaerobic test conditions

Facultative anaerobes are the most common cause of infections in anoxic parts of the human body, including deep wound, vagina, periodontal pockets, gastrointestinal tract, genitourinary tract and lungs. Generally, antibiotic susceptibility tests (AST) for facultative anaerobes are performed under aerobic conditions due to ease of handling and rapid growth. However, variation in susceptibility of facultative anaerobes to antibiotics under aerobic and anaerobic conditions can lead to failure of antibiotic treatment. Our study evaluated the susceptibility of facultative anaerobic microorganisms to antibiotics during growth under anaerobic or aerobic conditions. We compared the resistance patterns of representatives from 15 bacterial genera isolated from the human-gastrointestinal tract against 22 different antibiotics from six classes under aerobic and anaerobic conditions. Preliminary results obtained by a disc diffusion method were verified using minimum inhibitory concentration (MIC) testing. The results demonstrated that 7-strains had a similar pattern of drug resistance under both conditions, while the remaining ten strains had significant differences in resistance patterns between aerobic and anaerobic conditions for at least one antibiotic. We conclude that successful antibiotic therapy for host-associated pathogens requires proper assessment of the oxygen condition of the growth environment and MIC testing of each pathogen under anaerobic and aerobic conditions.

Antibiotic Resistance of Bacteria in Two Marine Mammal Species, Harbor Seals and Harbor Porpoises, Living in an Urban Marine Ecosystem, the Salish Sea, Washington State, USA

The pervasive use of antibiotics in human medicine, veterinary medicine, and agriculture can result in a significant increase in the spread and environmental persistence of antibiotic resistance in marine ecosystems. This study describes the presence and distribution of antibiotic-resistant bacteria in Salish Sea harbor seals (Phoca vitulina) and harbor porpoises (Phocoena phocoena) and evaluates species, age class, and geographic differences in resistance patterns. Isolates from 95 dead-stranded animals (74 seals/21 porpoises) were tested for resistance to a suite of 15 antibiotics. Of the 95 sampled, 85 (89%) (67 seals/18 porpoises) successfully yielded 144 isolates, with 37% resistant to at least one antibiotic and 26% multi-drug resistant (24% and 39% of seal and porpoise isolates, respectively). Overall, and by study region, porpoises were significantly more likely to harbor resistant organisms compared to seals. Significant differences between age classes were noted for the antibiotics amoxicillin, cephalexin, and cefovecin. Overall isolate resistance was significantly greater in porpoises than seals for several individual antibiotics. Multiple antibiotic resistance (MAR) indices greater than 0.2 were observed in 55% of multi-drug resistant isolates, suggesting seal and porpoise exposure to anthropogenic pollution. The relatively high and disparate prevalence of antibiotic resistance in these common, but ecologically dissimilar, marine mammals reflects a potentially large environmental pool of antibiotic resistant organisms in the Salish Sea or inherently different resistance gene patterns between the two species.

182. increasing Odds of Resistance for Subsequent Urinary e. Coli Isolates

BackgroundAnnual cumulative antibiograms are routinely used by clinicians to guide selection of empirical antibiotic therapies. CLSI guidelines recommend that these antibiograms to analyze data yearly, include only final, verified results, include bacterial species with > 30 isolates and to include only the first isolate for each species/patient instance per analysis period. Handling multiple isolates from individual patients in cumulative antibiograms is a controversial topic within the antimicrobial stewardship community. Current practice favors removing subsequent isolates, thereby discarding data reflecting impact of selective antibiotic pressure on resistance patterns in recurring urinary tract infection (UTI).In this study we analyzed a five-year data set of deidentified outpatient antibiotic results from a commercial laboratory to determine whether there were significant differences in resistance patterns between first and subsequent isolates from the same patient.MethodsThe 5-year antibiotic susceptibility data was restricted to urinary Escherichia coli (EC) isolates. Patient occurrence(s) of urinary EC were categorized by frequency: 1st occurrence, 2nd occurrence, 3rd occurrence, and 4th or greater occurrence. A logistic regression analysis using a binary outcome for resistance and independent variable of patient isolate occurrence was run for amoxicillin-clavulanate, ampicillin, ceftriaxone, ciprofloxacin, gentamicin, levofloxacin, nitrofurantoin, and trimethoprim-sulfa.ResultsFrom a logistic regression analysis, we estimate that for each occurrence in the data, an isolate’s odds of resistance were higher for every increase in a patient’s number of occurrences in the data for all antibiotics reported with p values < 0.0001.Table 1: Odds ratios (OR) of resistance for each subsequent urinary EC isolate occurrence over 5 years ConclusionOur findings suggest that individuals with higher numbers of urinary EC occurrences have more resistant EC than the first EC occurrence, with effects that vary by antibiotic class. Although traditional antibiograms include only the first occurrence of urinary EC from a single patient, this approach may underestimate levels of reservoir resistance in a community. Such an underestimation likely impacts efficacy of empiric therapeutic choice, healthcare outcomes, and cost.Disclosures All Authors: No reported disclosures

1669. Antimicrobial Resistance Patterns of Uropathogenic Escherichia coli: Comparison of Infection Setting and Community Classification

BackgroundThis study describes antibiotic resistance rates for Escherichia coli (E. coli) urinary tract infections (UTIs) and assesses differences in resistance patterns based on setting and community classification.MethodsA cross-sectional study design was used to analyze antibiotic resistance patterns of E. coli isolates from 12,600 urine cultures processed at a large hospital system in North Carolina from 2016 to 2018. Overall 3-year and annual resistance rates of uropathogenic E. coli to routinely tested first-line antibiotics were determined. Antibiotic resistance rates per 1000 patients were compared based on setting of infection acquisition (hospital vs. community) and community classification (urban vs. rural). T-test and chi-square tests were used to compare extended spectrum beta-lactamases (ESBLs) by demographic factors and setting. Analyses were performed using SAS Version 9.3 (SAS Institute, Cary, NC) at alpha=0.05.ResultsThree-year resistance rates were highest to ampicillin (42.2%), ampicillin-sulbactam (24.7%), ciprofloxacin (21.8%), trimethoprim-sulfamethoxazole (21.6%), and levoflaxacin (21.4%). Resistance was lowest for amikacin (0.06%), meropenem (0.08%), piperacillin-tazobactam (1.3%), nitrofurantoin (1.4%), and tobramycin (1.8%). Overall resistance rates were significantly higher in hospital- compared to community-acquired UTIs (p< 0.05) with the exception of amikacin, gentamicin, and meropenem. Significant differences in E. coli resistance rates were observed for patients from rural compared to urban counties for these antibiotics: levoflaxacin (233.6 vs. 208.3, p=0.003), ciprofloxacin (239.3 vs. 211.8, p=0.002), and nitrofurantoin (19.6 vs. 12.2, p=0.003). Prevalence of ESBL-producing E. coli was significantly higher among the elderly (p< 0.001), males (p< 0.001), inpatients (p< 0.001), and catheterized patients (p< 0.001).ConclusionResistance to first-line fluoroquinolones and nitrofurantoin was more prevalent in patients from rural compared to urban areas. Resistance rates and ESBL prevalence were significantly higher for hospital-acquired UTIs. Our findings have important implications for the empirical treatment of UTIs based on geographical area and setting.Disclosures All Authors: No reported disclosures

Antibiotic resistance in urinary tract infections: A re-visit after five years and experience over two sites.

The aim of this study was to repeat a previous audit, performed from 2009 to 2013, for the cohort of 2018 to determine how the resistance rates in urinary pathogens in women over 18 years of age have changed. A secondary aim of the study was to use resistance data from a different UK hospital in the same year to compare differences in resistance rates across different geographic locations. This was a retrospective study of all positive urine cultures grown from female patients attending two different hospitals in the year 2018. Resistance patterns were analysed. The resistance rate to co-amoxiclav continues to increase with amoxicillin retaining high resistance patterns. There are some significant differences in resistance patterns between the different locations. Antimicrobial resistance is a significant problem in the UK particularly in antibiotics used to treat UTI. These patterns can vary across different geographical locations and over time; therefore, up-to-date knowledge of local anti-biotic resistance is essential when making an appropriate prescription choice.

Neoadjuvant Chemotherapy Alters The Biliary Microbiome In Patients With Ductal Adenocarcinoma Undergoing Pancreaticoduodenectomy

Presenter: Syed Omair Nadeem MBBS | Emory University Background: Postoperative infectious complications constitute a major source of morbidity in pancreatic surgery. For patients with pancreatic ductal adenocarcinoma (PDAC), the use of neoadjuvant chemotherapy is becoming more commonly adopted. Yet data is limited regarding its impact on the biliary microbiome. It has been hypothesized that the currently recommended peri-operative antibiotic coverages may be inadequate prophylaxis for patients undergoing pancreatic resection. The aim of this study was to determine the effect of neoadjuvant therapy on the biliary microbiome in patients with and without preoperative stenting as a surrogate for overall patient microbiome status Methods: Demographic, operative, post-operative, and biliary pathogen morphology and antibiotic sensitivity data was reviewed from consecutive patients with pathologically confirmed PDAC from January 2014 to December 2017. Data was expressed as percentages. Chi square and ANOVA testing was performed for comparison between groups. Results: A total of 263 patients with PDAC were identified. 258 cases with complete stent data were included in the analysis. Of them 199 (77.1%) had received preoperative stenting, amongst whom 71 (35.7%) had received neoadjuvant chemotherapy. Ancef/Flagyl (n=167, 84%) was the most common antibiotic combination for perioperative prophylaxis followed by Clindamycin/Aztreonam (n=16, 8%). There were no significant differences in baseline characteristics between the people who did and did not receive neoadjuvant chemotherapy. The most common pathogens isolated from biliary cultures were Klebsiella Pneumoniae (n=31, 18.5%), Enterobacter Clocae (n=20, 11.9%) and E.Coli (n=16, 9.5%). Patients who did not receive neoadjuvant chemotherapy were more likely to grow, fungi (5.5% vs 0% p=0.039), E.Coli and Enterobacter (25% vs 12.7%, p=0.039). However, growth of Gram-negative anaerobes (32.4% vs 18.8%, p= 0.030) and unspecified bacterial species (31% compared to 14.8%, p=0.007) was higher in the patients who received neoadjuvant chemotherapy. Patients who did not receive neoadjuvant therapy were more likely to grow gram-negative pathogens resistant to Ampicillin-Sulbactam (47% vs 21%, p=0.007), Cefazolin (49% vs 28%, p=0.040), Cefoxitin (42% vs 11%, p=0.009) and Cefuroxime (26% vs 4%, p=0.019) than the patients who did receive neoadjuvant chemotherapy. No differences were seen in resistance to Ampicillin (p=0.376), Aztreonam (p=0.977), Cefepime (p=0.172), Ceftriaxone (p=0.183) and Piperacillin-Tazobactam (p=0.36) (figure 1). Stratified by stent status, there were no differences in resistance patterns among patients who did and did not receive neoadjuvant chemotherapy. Conclusion: Neoadjuvant chemotherapy significantly alters the biliary microbiome in patients with PDAC undergoing pancreaticoduodenectomy. Patients who did not receive neoadjuvant chemotherapy were more likely to grow pathogens resistant to cephalosporin antibiotics and have fungal colonization of their bile compared to patients who did receive neoadjuvant chemotherapy. Perioperative antibiotic coverage should be tailored to cover enterococci and gram negative organisms, especially for the subset of patients who had a biliary stent placed

ANTIMICROBIAL PHENOTYPES OF GEOGRAPHICALLY MATCHED Staphylococcus aureus ISOLATED FROM BUFFALO’S MILK AND CLINICAL HUMAN CASES IN EGYPT: POTENTIAL ZOONOTIC RISKS

Global emergence of antibiotic-resistant food-borne pathogens is a major public health problem. This study aimed to determine the potential zoonotic risk of Staphylococcus aureus in buffalo's milk in Egypt. A total of 102 raw buffalo’s milk samples and 51 human nasal swabs were collected at Kafrelsheikh city, Egypt. All samples were examined for occurrence of S. aureus. Detected isolates were characterised based on DNase activity, mecA gene acquisition, and antibiotic resistance patterns. S. aureus was detected in 33.3% of buffalo's milk samples and29.4% of human nasal swabs. Multiple drug-resistant S.aureus (MDRSA) represented 88.2% and 90% of buffalo and human S. aureus isolates, respectively. Buffalo and human S. aureus isolates showed highest resistance rate for erythromycin (100%), and lowest resistance rate for gentamicin (22.2%). Interestingly, there was no significant difference in resistance patterns between methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) (P&lt;0.46 - 0.97). One-third of the detected S. aureus phenotypes (5/15, 33.3%) were identical between buffalo and human isolates. Moreover, there was no significant difference in antibiotic resistance patterns between buffalo and human isolates (P&lt;0.1 - 0.97).This study highlights the potential public health risk of MDRSA transmission via buffalo's milk.Key words: buffalo’s milk, S. aureus, DNase, mecA, antibiogram, zoonotic risk

Resistance patterns of Enterobacteriaceae in urines are similar in symptomatic and asymptomatic patients

Antibiograms of urine cultures are being used to guide empiric treatment for urinary tract infections (UTIs). However, roughly 50% of urine cultures are from patients with asymptomatic bacteriuria (ABU). It is unclear whether Enterobacteriaceae in ABU patients have similar resistance patterns as UTI patients. Hence, we aimed to compare the antimicrobial resistance patterns in patients with ABU to patients with symptomatic UTI. We found no major differences in resistance patterns, and therefore empiric treatment choices can be guided by antibiograms that include ABU patients.

Resistance to First-Line Antituberculosis Drugs in Washington State by Region of Birth and Implications for Latent Tuberculosis Treatment Among Foreign-Born Individuals.

The United States has a low burden of drug resistance among tuberculosis (TB) cases compared with other world regions. TB is increasingly concentrated among foreign-born individuals who have higher rates of drug resistance than U.S.-born individuals. While universal drug susceptibility testing is the standard for detecting active tuberculosis, there are limited guidelines for latent tuberculosis infection (LTBI) treatment based on risk factors for drug resistance. To quantify the variable risk of drug resistance among foreign-born individuals, all TB cases in Washington State between 1994 and 2014 with drug resistance data for isoniazid, rifampin, pyrazinamide, and ethambutol were divided into eight regions of birth. Logistic regression was used to characterize regional differences in resistance patterns. Genotypic cluster and lineage data were compared against drug resistance in a subanalysis. Among 4,298 cases, isoniazid resistance was more common in foreign-born individuals (12.6% versus 4.8%; P < 0.001), with the highest burden among individuals from the Asia-Pacific (14.8%) region. Rifampin resistance was slightly higher among foreign-born individuals (1.9% versus 1.1%; P = 0.063). Multivariate logistic regression demonstrated that older age was associated with a lower risk of resistance to isoniazid and rifampin (odds ratio [OR] = 0.86, P = 0.006 and OR = 0.64, P = 0.003 for each 20-year interval, respectively). These data suggest drug resistance in LTBI will remain a challenge and that rifampin-based regimens for treatment of LTBI in non-human immunodeficiency virus-infected adults may be preferable for individuals born in regions with high levels of isoniazid resistance. However, further research is needed to demonstrate whether LTBI treatment based on region of birth further decreases TB reactivation.

Comparison of livestock-associated and health care–associated MRSA—genes, virulence, and resistance

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) may colonize and infect humans with close contact to pigs. We compared phenotypic and genotypic differences in resistance and virulence of LA-MRSA isolates from farms and farmers with hospital-acquired methicillin-resistant S. aureus (HA-MRSA) and assessed carriage rates. Samples from pigs (n=330), occupationally exposed personnel (n=63), the farm environment (n=134), and hospital patients (n=220) were obtained. Approximately 50% (166/330) of pigs were MRSA positive. All LA-MRSA were resistant to tetracycline, compared to only 8% of HA-MRSA (P<0.001). In contrast, HA-MRSA isolates showed significantly higher resistance rates to quinolones (81% versus 7%; P<0.001). All strains isolated from occupationally exposed personnel (61.9%; 39/63) belonged to CC398. HA-MRSA isolates were diversely distributed, with predominance of CC5 (62.7%). Human strains carried significantly more virulence genes than porcine strains, especially exotoxins (P<0.001) and immune-evasion cluster genes (P<0.001). There were significant differences in resistance patterns and recognized genotypic virulence loci between LA-MRSA and HA-MRSA.

A Preliminary Investigation of Ethnic Differences in Resistance in Multisystemic Therapy

Therapy process research suggests that an inverted U-shaped trajectory of client resistance, referred to as the struggle-and-working-through pattern, predicts positive treatment outcomes. However, this research may lack external validity given the exclusive focus on European Americans. This preliminary study explores differences in resistance patterns in a sample of African American and European American juvenile drug offenders and their families (n = 41) participating in Multisystemic Therapy. Resistance was coded from session recordings at the beginning, middle, and end of treatment. There were significant ethnic differences in (a) mean resistance at midtreatment, (b) resistance trajectories, and (c) predictive relationships between resistance trajectories and criminal desistance. Notably, a negative quadratic (i.e., inverted U-shaped) resistance trajectory was more characteristic of European Americans who desisted from crime, whereas a positive quadratic (U-shaped) resistance pattern was more characteristic of African Americans who desisted. There was no relationship between resistance trajectory and later drug abstinence (i.e., cannabis). Within the context of evidence-based therapies, core treatment processes may vary significantly as a function of client ethnicity. We recommend that clinical scientists make efforts to test for ethnic differences in treatment process so that therapies like Multisystemic Therapy can be understood in a more comprehensive and nuanced manner.

Prevalence and antimicrobial resistance of Campylobacter species isolated from the avian eggs

Campylobacter is one of the most important food borne pathogens that cause bacterial gastroenteritis worldwide. The most commonly isolated species in humans are Campylobacter jejuni (C. jejuni) and Campylobacter coli. The emergence of antimicrobial resistance in Campylobacter spp. has been a growing public health concern globally. Information about antimicrobial resistance of Campylobacter at different levels of production is important for the development of control strategies for this pathogen. This study was conducted to determine the prevalence and antimicrobial resistance of Campylobacter spp. isolated from different eggs from different avian species in Iran. A total of 440 egg samples were collected from different avian and analyzed for the presence of Campylobacter spp. in eggshell and eggs content under sterile conditions using Campylobacter selective agar base and the species were identified by biochemical tests. The suspected colonies were subjected to PCR assay for final confirmation as Campylobacter spp., and identification of C. jejuni or Campylobacter coli. Antimicrobial susceptibility testing was performed by the Kirby–Bauer disk diffusion method using Mueller Hinton agar. Campylobacters were detected in a total of 7 out of 100 (7%) eggshell of chicken samples and in 3 out of 60 (5%) eggshell of duck samples. In addition, Campylobacter spp. were also detected in 3.3%, 2.5%, 4.2%, 5% and 3.8 of the eggshell of goose, ostrich, partridge, quail and turkey samples, respectively. The overall prevalence rate of Campylobacter species from different avian eggs was found to be 7.7% (34/440). Among different avian egg samples, Campylobacter jejuni was more frequently isolated 28 (n = 28, 6.3%) than C. coli 6 (n = 6, 1.3%). In addition, the prevalence of C. jejuni was highest in summer and lowest in autumn. In this study Campylobacter spp. showed significant difference in resistance pattern with tetracycline and ciprofloxacin but gentamicin resistance was not found in both C. coli and C. jejuni isolates. Therefore, gentamicin is safe and effective drugs for the treatment of human campylobacteriosis if avian egg is considered as the source of infection.

Comparison of Mannheimia haemolytica isolates from an outbreak of bovine respiratory disease

The objective of this study was to determine the clonal relatedness of Mannheimia haemolytica isolates responsible for an outbreak of bovine respiratory disease in a commercial feedlot. The isolates were obtained from the lungs of 21 calves with fatal pneumonia that were part of a group of 206 total calves. All isolates were serotyped and analyzed by pulsed-field gel electrophoresis (PFGE) and for antibiotic sensitivity patterns. ELISA and immunoblotting assays were performed to compare serum antibody levels to M. haemolytica antigens in calves with fatal pneumonia to those calves that survived the outbreak. Isolates were categorized into 14 different PFGE groups based on 90% similarity. Two Group D isolates (1 and 6), and 3 Group H isolates (14, 15, and 16) were characterized as 100% similar. Antimicrobial susceptibility profiles defined 8 groups based on differences in patterns of resistance between isolates. The two 100% similar isolates from PFGE Group D were both in susceptibility Group 1. All but isolate 14 from PFGE Group H (3, 15, 16, and 19) were in susceptibility Group 4a. Serum antibody levels to M. haemolytica antigens in the dead calves were not different than the antibody levels in the 185 calves that survived the outbreak. Immunoblots of selected isolates from each of the PFGE groups demonstrated only minimal differences in antigenic profiles between strains when reacted with serum from calves that either died from or survived the outbreak. Based on the characteristics of these isolates, multiple strains of M. haemolytica were responsible for fatal pneumonia during this outbreak.