Coagulase-negative Staphylococci Species Research Articles

Coagulase-negative staphylococci as an evolving mastitis causing organism in cows: A review

The present review attempts to address the emergence of a fast-growing mastitis causing pathogen – coagulase-negative staphylococci (CNS) – and its multi-facet roles in dairy farms. CNS is divided into numerous species, but only a few succeed in bovine mastitis. The two predominant CNS species causing mastitis are Staphylococcus chromogenes and Staphylococcus simulans. These two mostly known CNS affects dairy cows at varied parities and at different lactation stages. CNS have been judged to be the most common bovine mastitis isolate in several countries of the world. However, CNS may not likely be as pathogenic as the other primary mastitis pathogens such as Staphylococcus aureus and its infection mostly remains subclinical. Conversely, CNS is capable of triggering persistent infections among dairy herds, resulting in reduced milk quality and high milk somatic cell count (SCC). One negative impact of CNS infection in dairy herds is that it can destroy cow udder tissue, hereby leading to a drop in milk production of dairy cows. CNS mastitis has a high cure rate when treated with anti-biotics as their infection in cows are not known to be a therapeutic problem. Judging from several literatures, it cannot be said whether CNS species act as an ecological or contagious pathogens. Regulator procedures, including pre- and post-milking teat disinfection, may reduce contagious mastitis pathogens of CNS infections in the dairy herd. Phenotypic methods for identification of CNS are not adequately dependable, and molecular techniques of identification may be better substitute for identification. Dairy farmers may benefit greatly from more empirical research on the epidemiology of CNS mastitis and more reliable methods for species identification.

Prevalence of mecA and pvl genes in coagulase negative staphylococci isolated from bovine mastitis in smallholder dairy farms in Turkey

This study aimed to investigate the presence of mecA and pvl genes in coagulase negative Staphylococcus (CNS) species isolated from bovine mastitis in smallholder dairy farms by using PCR. A total of 602 mammary quarter milk samples belong to 170 cows with mastitis were used. Identification of species was achieved by using the commercial Gram-positive identification kit and a total of 52 (8.6%) CNS species were isolated. The most frequently isolated species was Staphylococcus capitis (n = 15, 28.8%), followed by Staphylococcus saccharolyticus (n = 12, 23.1%), Staphylococcus simulans (n = 8, 15.4%), Staphylococcus haemolyticus (n = 5, 9.6%), Staphylococcus cohnii (n = 4, 7.7%), Staphylococcus lentus (n = 4, 7.7%), Staphylococcus epidermidis (n = 2, 3.8%) and Staphylococcus saprophyticus (n = 2, 3.8%). The mecA gene positivity was found in the 13 (25%) of strains. Of the strains carrying mecA gene, eight also harbored the pvl gene. A total of pvl gene positivity was found as 30.8% (n = 16) in 52 CNS species. In conclusion, the present study showed that CNS isolated from cows with mastitis may be reservoir of mecA and pvl genes. To our knowledge, this is the first study showing the presence of mecA and pvl genes in CNS species isolated from bovine with mastitis in the smallholder dairy farms in Turkey.

A Microbiological Study on Clinical Isolates of Coagulase-Negative Staphylococci (CoNS) from Sulaimaniyah Hospitals

The purpose of this study was to identify and isolate different coagulase.negative staphylococci (CoNS) species associated with clinical samples with their virulence factors. For this purpose, 355 clinical samples were taken from various Hospitals in Sulaimaniyah city. Different species of CoNS were identified by using (blood, MacConkey, Mannitol salt) agars, biochemical tests, and VITEK® 2 compact system. The phenotypic characterization of hemolysin was based on the hemolysis pattern of CoNS on sheep blood agar. Moreover, the biofilm detection in CoNS was performed by using a microtiter plate (MTP). The various biofilm and virulence genes were detected using specific primers to detect mecA, hla, hlb, hld, hlg and the icaAD, fnbA, and bap genes, respectively. The number of MR-CoNS and MS-CoNS were 31 (96.8%) and 1 (3.1%), respectively, out of 32 isolates. The availability of the mecA gene, responsible for the resistance of CoNS to methicillin, was found in (100%) of CoNS species related to clinical samples. Interestingly, the hemolysin genes were detected on the plasmids instead of the chromosomal DNA, and these results indicated that the CoNS could be the primary cause of nosocomial infection.

Persistent Coagulase-Negative Staphylococcal Bacteremia in Neonates: Clinical, Microbiological Characteristics and Changes within a Decade.

Atypical outbreaks of persistent coagulase-negative staphylococci (CoNS) bacteremias, defined as three or more consecutive positive blood cultures with the same CoNS species, at least 48 h apart, have been reported in neonatal intensive-care units (NICUs). Our aim was to describe the profile of these cases in our NICU over a two-year period with the objective of assessing possible changes within a decade. Demographics, clinical and microbiological data were recorded for all CoNS bacteremias in our tertiary NICU during 2016–2017 and compared with the results of the same study in 2006–2007. Fifty-six cases of CoNS sepsis were recorded. Fourteen (25%) of them were persistent. There were no significant differences in demographic and clinical characteristics between cases with persistent vs. non-persistent bacteremia. Staphylococcus epidermidis was the most common species. In logistic regression analysis, biofilm production (β = 2.464, p = 0.04) was the most significant determinant for the development of persistent CoNS bacteremia. Our isolates were less likely to produce biofilm and carry ica operon as compared to those of 2006–2007. The cases of persistent CoNS sepsis have decreased within a decade, which could be attributed to the implementation of intensive infection control practices. Biofilm production remains the most important risk factor.

The Ubiquitous Human Skin Commensal Staphylococcus hominis Protects against Opportunistic Pathogens.

ABSTRACTStaphylococcus hominis is frequently isolated from human skin, and we hypothesize that it may protect the cutaneous barrier from opportunistic pathogens. We determined that S. hominis makes six unique autoinducing peptide (AIP) signals that inhibit the major virulence factor accessory gene regulator (agr) quorum sensing system of Staphylococcus aureus. We solved and confirmed the structures of three novel AIP signals in conditioned medium by mass spectrometry and then validated synthetic AIP activity against all S. aureus agr classes. Synthetic AIPs also inhibited the conserved agr system in a related species, Staphylococcus epidermidis. We determined the distribution of S. hominis agr types on healthy human skin and found S. hominis agr-I and agr-II were highly represented across subjects. Further, synthetic AIP-II was protective in vivo against S. aureus-associated dermonecrotic or epicutaneous injury. Together, these findings demonstrate that a ubiquitous colonizer of human skin has a fundamentally protective role against opportunistic damage.

Asymptomatic bacteriospermia and infertility—what is the connection?

ObjectiveTo determine the impact of asymptomatic bacteriospermia on semen quality in subfertile men.MethodsWe conducted a retrospective, single-centre cohort study in 1300 subfertile men. In those diagnosed with asymptomatic bacteriospermia we performed univariate and multivariate logistic regression models to evaluate the strain-specific association with semen parameters.ResultsAsymptomatic bacteriospermia was diagnosed in 3.2% of patients. The microbiological semen analysis revealed a poly-microbial result in 60%. The most common bacterial species were coagulase-negative Staphylococci species (71.4%), Streptococcus viridans (50.0%) and Enterococcus faecalis (26.2%). Sexually transmitted pathogens were identified in 11.9% of semen samples. The detection of Streptococcus viridians or Haemophilus parainfluenzae correlated with impaired sperm morphology (p < 0.05). The presence of coagulase-negative Staphylococci species or Enterococcus faecalis was associated with pathological low counts of live spermatozoa (p < 0.05). In multivariate analysis only Enterococcus faecalis showed a significant impact on sperm concentration (OR 4.48; 95% CI 1.06–22.10; p = 0.041).ConclusionsAsymptomatic bacteriospermia has always been a subject of great controversy. There is still an ongoing debate whether to treat or not to treat. Here, we demonstrate that asymptomatic bacteriospermia is clearly associated with impaired semen quality. Our findings speak in favour of strain-specific interactions with semen parameters. Especially Enterococcus faecalis seriously affects sperm concentration.

Prevalence and Antimicrobial Resistance of Staphylococcus aureus and Coagulase-Negative Staphylococcus/Mammaliicoccus from Retail Ground Meat: Identification of Broad Genetic Diversity in Fosfomycin Resistance Gene fosB.

Staphylococcus is a major bacterial species that contaminates retail meat products. The objective of this study was to clarify the prevalence, antimicrobial resistance and genetic determinants of Staphylococcus/Mammaliicoccus species in retail ground meat in Japan. From a total of 146 retail ground meat samples (chicken, pork, mixed beef/pork) purchased during a 5-month period, 10 S. aureus and 112 isolates of coagulase-negative staphylococcus (CoNS)/Mammaliicoccus comprising 20 species were recovered. S. aureus isolates were classified into five genetic types, i.e., coa-IIa/ST5, coa-VIc/ST352 (CC97), coa-VIIb/ST398, coa-Xa/ST15, and coa-XIc/ST9, which were all related to those of livestock-associated clones. All the staphylococcal isolates were mecA-negative and mostly susceptible to all the antimicrobials tested, except for ampicillin among S. aureus (resistance proportion; 50%). Among CoNS, the fosfomycin resistance gene fosB was prevalent (30/112; 26.8%), primarily in S. capitis, S. warneri, and S. saprophyticus. Phylogenetic analysis of fosB revealed the presence of seven clusters, showing broad diversity with 65–81% identity among different clusters. In the CoNS isolates from ground meat samples, fosB was assigned into three clusters, and S. saprophyticus harbored the most divergent fosB with three genetic groups. These findings suggested the circulation of multiple fosB-carrying plasmids among some CoNS species.

The first reported case of Staphylococcus pettenkoferi prosthetic joint infection

Staphylococcus aureus and Staphylococcus epidermidis are among the most frequent causes of prosthetic joint infections (PJIs). Staphylococcus pettenkoferi, a coagulase-negative Staphylococcal species first described in 2002, has been detected in fewer than 20 patients with true infection (15 cases of bacteremia and 1 case of osteomyelitis). This organism has never been implicated in a PJI, likely owing in part to the difficulty in identification via biochemical methods. S. pettenkoferi is almost universally reported to be a contaminant when detected. We report the first case of a PJI caused by S. pettenkoferi, highlighting its infectious potential in specific patient populations.

Antibiotic Resistance Patterns of Coagulase-Negative Staphylococcus (CoNS) Isolates from a Major Teaching Hospital in Kuala Lumpur, Malaysia

Coagulase-negative Staphylococcus (CoNS) species is a leading cause of nosocomial infection in patients with indwelling medical devices and immunocompromised patients. This study was conducted to determine the antibiotic resistance pattern of CoNS isolated from a major teaching hospital in Malaysia. A total of 43 CoNS isolates were collected from August to October 2018 at Hospital Canselor Tuanku Muhriz, Kuala Lumpur, Malaysia. Speciation of CoNS species was conducted by 16S rRNA sequencing. Antibiotic susceptibility test was performed using a standard procedure, and detection of staphylococcal cassette chromosome mec (SCCmec) elements and antibiotic resistance genes were conducted via multiplex polymerase chain reaction (PCR). Comparison of 16S rRNA sequences showed that 67.44% of the isolates were identified as S. epidermidis, followed by S. haemolyticus (11.63%), S. hominis (9.3%), S. capitis (4.65%), and other Staphylococcus sp. (6.98%). All the CoNS isolates were susceptible to linezolid and tedizolid, while most of them were resistant towards penicillin (86.05%), cefoxitin (69.77%), erythromycin (72.02%), and 88.37% of them were resistant to at least 3 antibiotics. The majority of CoNS harboured nontypeable SCCmec elements. AacA-D (95.5%) and ermC (78.6%) were the most commonly detected antibiotic resistance genes while no detection of tetK, tetM and ermA genes were observed. This study showed a high prevalence of multidrug-resistant CoNS in HCTM healthcare settings. Understanding CoNS resistance mechanism is warranted for intervention strategy.

Enolase of Staphylococcus lugdunensis Is a Surface-Exposed Moonlighting Protein That Binds to Extracellular Matrix and the Plasminogen/Plasmin System.

The coagulase-negative staphylococcal (CoNS) species Staphylococcus lugdunensis is unique in causing serious infections in humans that resemble those of Staphylococcus aureus rather than those of other CoNS species. The colonization and invasion of host tissue presupposes the presence of adherence factors, but only a few proteins mediating adhesion of S. lugdunensis to biotic surfaces are known yet. Here, we report on the functionality of the S. lugdunensis enolase (SlEno), which performs two distinct roles, first, as the metabolic enzyme of the glycolysis, and second, as an adherence factor to the extracellular matrix (ECM) of cells. Phylogenetic analyses of the SlEno confirmed their high conservation to enolases of other species and revealed a closer relationship to Staphylococcus epidermidis than to S. aureus. Using matrix-assisted laser desorption/ionization time of flight mass spectrometry and Western blot experiments, we identified SlEno to be located in the cytoplasm as well as on the cell surface of S. lugdunensis. Recombinantly generated and surface-associated SlEno showed the usual enolase activity by catalyzing the conversion of 2-phosphoglycerate to phosphoenolpyruvate but, in addition, also displayed strong binding to immobilized laminin, fibronectin, fibrinogen, and collagen type IV in a dose-dependent manner. We also showed a strong binding of SlEno to plasminogen (Plg) and observed a tissue plasminogen activator (tPA)-dependent conversion of Plg to plasmin (Pln) whereby the Plg activation significantly increased in the presence of SlEno. This interaction might be dependent on lysines of the SlEno protein as binding to Plg was inhibited by ε-aminocaproic acid. Furthermore, the enhanced activation of the Plg/Pln system by SlEno enabled S. lugdunensis to migrate through a fibrin matrix. This migration was about 10-fold higher than without exogenously added SlEno. Finally, we observed a significantly higher clearance of S. lugdunensis by freshly prepared granulocytes and in the presence of anti-SlEno antibodies. In conclusion, these data demonstrate for the first time a moonlighting function of the S. lugdunensis enolase, which is an underrated virulence factor for colonization and invasion of tissues. Hence, SlEno might be a potential vaccine candidate to prevent severe infections caused by this pathogen.

Isolation and Identification of Biofilm-Producing, Drug-Resistant Coagulase Negative Staphylococci from a Hospital Environment in Northern Philippines

Healthcare-associated infections (HCAIs) are considered adverse outcomes of confinement in a healthcare facility. Biofilm-producing, drug-resistant bacteria have further aggravated the problem with HCAIs. This study determined the prevalence, antibiotic susceptibility, and biofilm phenotype of coagulase-negative staphylococci (CoNS) isolated from a hospital environment in Northern Philippines. The identification of CoNS species and the determination of antibiotic susceptibility were done using an automated assay. Biofilm production was detected using tissue culture plate (TCP) and Congo red agar (CRA) methods. Out of 220 surfaces and 26 air samples collected, 103 (41.9%) CoNS strains were isolated, predominated by S. epidermidis with 30.1% prevalence. The medical ward was found to have the highest prevalence of CoNS at 64%. The CoNS isolates exhibited a variable resistance profile; the highest was found against penicillin (97.1%) and oxacillin (54.3%). Isolates manifesting resistance to linezolid and vancomycin were also detected. From the 103 CoNS isolates, 52 (50.5%) biofilm producers were detected using the TCP method, and 39 (37.9%) were detected by the CRA method. Statistically significant difference was found between the biofilm biomass and the slime-producing pattern. This study revealed the prevalence of biofilm-producing, drug-resistant strains of CoNS in a Level 3 hospital in Northern Philippines. This warrants further enhancement of infection prevention and control programs to avert the emergence of more biofilm-producing, drug-resistant bacterial strains that could pose formidable threats to public health.

Staphylococcal Enterotoxin Genes in Coagulase-Negative Staphylococci-Stability, Expression, and Genomic Context.

In the current study, we screened a collection of coagulase-negative staphylococci (CoNS) isolates for orthologues of staphylococcal enterotoxins (SEs) involved in S. aureus-related staphylococcal food poisoning (SFP). The amplicons corresponding to SEs were detected in S. chromogenes, S. epidermidis, S. haemolyticus, S. borealis, S. pasteuri, S. saprophyticus, S. vitulinus, S. warneri, and S. xylosus. All amplicons were sequenced and identified as parts of known S. aureus or S. epidermidis SE genes. Quantitative real-time PCR allowed determining the relative copy number of each SE amplicon. A significant portion of the amplicons of the sea, seb, sec, and seh genes occurred at low copy numbers. Only the amplicons of the sec gene identified in three isolates of S. epidermidis displayed relative copy numbers comparable to sec in the reference enterotoxigenic S. aureus and S. epidermidis strains. Consecutive passages in microbiological media of selected CoNS isolates carrying low copy numbers of sea, seb, sec, and seh genes resulted in a decrease of gene copy number. S. epidermidis isolates harbored a high copy number of sec, which remained stable over the passages. We demonstrated that enterotoxin genes may occur at highly variable copy numbers in CoNS. However, we could identify enterotoxin genes only in whole-genome sequences of CoNS carrying them in a stable form at high copy numbers. Only those enterotoxins were expressed at the protein level. Our results indicate that PCR-based detection of enterotoxin genes in CoNS should always require an additional control, like analysis of their presence in the bacterial genome. We also demonstrate S. epidermidis as a CoNS species harboring SE genes in a stable form at a specific chromosome site and expressing them as a protein.

Comparison of Methods for Detecting Methicillin-Resistant Coagulase-Negative Staphylococci in Device-Associated Infections

Background: Coagulase-negative Staphylococci (CoNS) is one of the major causes of infections in hospitals. Methicillin resistance has greatly increased in different CoNS species in previous years. Here, we evaluated the performance of four phenotypic tests for detecting mecA-mediated methicillin resistance rate in CoNS isolated from different device-associated infections in Tanta University Hospitals, Egypt. Methodology: One hundred and fifteen CoNS isolates were examined for mecA-mediated methicillin resistance using polymerase chain reaction (PCR) as the standard gold test. Susceptibility to methicillin was investigated using VITEK 2 assay, oxacillin broth microdilution, and cefoxitin disc diffusion tests. Results: Of all isolates, 98.3% were mecA-positive. The sensitivities of the different methods examined were as follows: 100% for the VITEK cefoxitin test, 97.4% for the VITEK oxacillin test, 93.8% for the oxacillin broth microdilution, and 82.3% for the cefoxitin disc diffusion test. The test specificity could not be accurately determined because of the small number of mecA-negative isolates (n = 2). Conclusion: The rate of methicillin resistance reached 98.3% among CoNS isolates. Our results demonstrate that the VITEK 2 assay is rapid and has high sensitivity compared to other phenotypic methods for detecting methicillin resistance among different species of CoNS. Therefore, we recommend the dual measurement of both cefoxitin and oxacillin susceptibilities using the VITEK 2 assay for best results.

POS-718 CASE OF KOCURIA SPP. INDUCED PERITONEAL DIALYSIS RELATED PERITONITIS

Peritonitis is a serious complication of peritoneal dialysis (PD) and is commonly caused by coagulase negative staphylococcal species and staphylococcus aureus. PD related peritonitis contributes to death in up to 8.6% of patients and often results in transition to haemodialysis. In this case we illustrate a rare presentation of Kocuria causing recurrent, treatment resistant peritonitis that resulted in eventual cessation of PD and switch to haemodialysis. Kocuria species are commonly found as skin commensals on human and other mammal skin and rarely cause systemic infections in humans. Despite only 12 case reports of Kocuria induced peritonitis in patients undergoing PD having been reported, Kocuria is increasingly being recognised as an important pathogen in humans. We describe an 84 year old woman with end stage renal failure of an unknown aetiology who was commenced on PD in 2016. The patient was maintained on PD until November 2019 where she was admitted with Acinetobacter induced peritonitis that was treated with oral quinolones. In March 2021 she was admitted again with Kocuria Spp. induced peritonitis where she was treated with intraperitoneal vancomycin and oral ciprofloxacin. Despite displaying adequate sensitivities to these antibiotics, Kocuria Spp. continued to be cultured from her peritoneal fluid. As medical management of her peritonitis failed her PD line was removed in April 2021 and she was commenced on haemodialysis. This case is a good example of a rare microbe causing PD related peritonitis that, despite displaying wide ranging sensitives during laboratory testing, was resistant to intraperitoneal antibiotics. This case adds to the growing literature suggesting that Kocuria Spp. are important causative organisms of human disease and should be considered when designing treatment pathways for peritoneal dialysis related peritonitis.

Novel insights into the role of the mobilome in ecological diversification and success of Staphylococcus haemolyticus as an opportunistic pathogen.

Staphylococcus haemolyticus is a species of coagulase-negative staphylococci that has primarily been studied as a human skin microbiome member and an emerging nosocomial pathogen. Here, we present the first complete genome of S. haemolyticus strains SE3.9, SE3.8 and SE2.14 reported as an endophyte of rice seed. Detailed investigation of the genome dynamics of strains from diverse origins revealed an expanded genome size in clinical isolates, and a role of many insertion sequence (IS) elements in strain diversification. Interestingly, several of the IS elements are also unique or enriched in a particular habitat. Comparative studies also revealed the potential movement of mobile elements from rice endophytic S. haemolyticus to strains from other pathogenic species such as Staphylococcus aureus . The study highlights the importance of ecological studies in the systematic understanding of genome plasticity and management of medically important Staphylococcus species.

Bacteriological Profiles of Semen Culture in Male Patients Having Primary Infertility, Attending Mombasa Assisted Reproduction Centre

Background: Infertility is of global health concern affecting one out of six couples worldwide, and Africa has reported the highest rates. Bacterial semen infections are considered to be one of the significant causes of infertility. Effective antimicrobial therapy is therefore essential in treatment of bacteriospermia. This study aimed to identify the bacterial pathogens present in semen and involved performing the antimicrobial susceptibility testing to improve the clinical management by identifying the antimicrobials that can be the best treatment option.Methods: Ninety semen specimens were collected from male patients having primary infertility who attended the clinic. Semen was cultured on Nutrient agar, Blood agar, MacConkey agar and Chocolate blood agar using standard bacteriological techniques. Bacterial isolates identification was done by studying the colony characteristics, performing gram staining reactions and biochemical testing. Modified Kirby-Bauer method was used in performing the antimicrobial susceptibility testing.Result: 51 (56.67%) patients presented with bacteriospermia. Staphylococcus aureus (29.41%) was the most common bacteria isolated, followed by Escherichia coli (23.53%), Coagulase negative staphylococcus species (17.65%), Klebsiella pneumoniae (11.76%), Proteus. mirabilis (7.84%), Pseudomonas. aeruginosa (5.88%) and Neisseria gonorrhoeae (3.92%). Most of the bacteria isolated were highly sensitive to ciprofloxacin, cefotaxime and ofloxacin and moderately sensitive to amikacin, gentamycin and cefuroxime.Conclusion: Bacteriospermia prevalence rate was 56.67% and was commonly observed in the age group of 30 - 39 years. Staphylococcus aureus was found to be the predominant causative agent of semen infection. The most effective antimicrobials were ciprofloxacin, cefotaxime and ofloxacin and the antimicrobial with least activity was co-trimoxazole.

Identification of coagulase negative staphylococcal species from bovine mastitis in India.

Staphylococcal mastitis is a major cause of concern to the dairy industry in India and several countries worldwide. Though Staphylococcus aureus is the major cause, coagulase negative staphylococcal species (CoNS) are being increasingly reported in recent years. To investigate the incidence of coagulase negative staphylococcal species in bovine mastitis. Isolation of staphylococci was carried out from 237 milk samples of cows and She buffaloes with clinical and subclinical mastitis from different regions of Andhra Pradesh and Karnataka. CoNS isolates were identified by tube coagulase test using fresh rabbit plasma and coagulase gene PCR. We employed the biochemical test scheme published elsewhere previously for identification of the CoNS isolates up to species and subspecies levels. Seven representative isolates were identified by 16S rDNA sequencing to check the accuracy of biochemical test based identification. The CoNS constitute the majority of the staphylococcal isolates from mastitis (80/125, 64%) in this region. Using biochemical test scheme, the CoNS isolates from bovine mastitis were identified as S. cohnii sub sp. cohnii, S. simulans, S. capitis sub sp. capitis, S. cohnii sub sp. xylosus, and S. lugdunensis. The CoNS species S. schleiferi, S. haemolyticus, S. sciuri, S. xylosus, S. chromogenes, and Macrococcus epidermidis were identified by 16S rDNA sequencing. The 16S rDNA sequencing is the appropriate method for the identification of CoNS species. This study highlighted coagulase negative staphylococcal species as possible etiological agents of mastitis.

Investigations on some aerobic bacterial agents isolated from heifers at the beginning ofthe first lactation

In this study, it was aimed to identify the predominant coagulase-negative staphylococci (CNS) species in subclinical, clinical, and persistent infections in Konya province, to determine various virulence and resistance mechanisms of CNS species within the agelactation level. The research has been carried out in a dairy herd that is free from brucellosis and tuberculosis and uses an automated herd management system. Thirty-two heifers at the beginning of lactation with milk yields of more than 20 liters have been observed in terms of udder infections during the first 1-4 months of lactation. The prevalence of intramammary infections (IMI) and of CNS-caused IMI has been 75% and 53%, respectively. The rate of CNS was 61% among all isolates, with the rate of the major pathogen 26%, and the rate of the other pathogen 12%. S. chromogenes has been the most frequently isolated CNS species (45.5%). In conclusion, CNS may cause udder infections at the herd level in heifers during the early lactation period, which may cause persistent infections with different mechanisms, and S. chromogenes may emerge as a new contagious mastitis agent in the future. CNSs should be identified at the species level rather than the group level in order to develop effective control programs. Based on the epidemiological data, the current udder health control programs in heifers in the early lactation period were detected to be insufficient.

Speciation and Antibiotic Susceptibility Pattern of Coagulase Negative Staphylococci in a Tertiary Care Hospital of Manipur, India

Introduction: Coagulase Negative Staphylococci (CoNS) are common opportunistic pathogens. They are increasingly being recognised as nosocomial pathogens and are associated with multiple antimicrobial resistance mechanisms particularly methicillin resistance. Therefore, rapid and reliable identification upto the species level is necessary to predict the potential pathogenicity or antibiotic susceptibility of each clinical isolate. Aim: Isolation and speciation of CoNS from various clinical samples, and to determine their antibiotic susceptibility pattern. Materials and Methods: This study was a hospital-based crosssectional study carried out in the Department of Microbiology, Jawaharlal Nehru Institute of Medical Sciences (JNIMS), Imphal, Manipur, India, during the period from September 2017- August 2019. CoNS isolates were identified using conventional microbiological procedures and speciation was done following the scheme of Kloos and Schleifer. Antibiotic susceptibility was determined by using the Kirby Bauer’s disk diffusion method. Detection of methicillin resistance among CoNS was performed using cefoxitin disk (30 µg) diffusion method. Data analysis was done using descriptive statistics. Results: CoNS isolates were identified from different clinical specimens, which included 88 (65.2%) from urine, 37 (27.5%) from blood, 3 (2.2%) from pus, 2 (1.5%) from catheter tip, 2 (1.5%) from wound swab, 1 (0.7%) each from aural swab, sputum and ascitic fluid. Predominant isolates were Staphylococcus epidermidis (40.7%) followed by Staphylococcus haemolyticus (19.3%), Staphylococcus hominis (11.9%), Staphylococcus xylosus (7.4%), Staphylococcus saprophyticus (6.0%), Staphylococcus schleiferi (5.2%), Staphylococcus simulans (4.4%), Staphylococcus warneri (3.0%), Staphylococcus lugdunensis (0.7%), Staphylococcus capitis (0.7%) and Staphylococcus cohnii (0.7%). Most isolates were resistant to penicillin (84.5%) and erythromycin (59.3%), and least to tigecycline (2.2%). No resistance to vancomycin and linezolid was seen. Methicillin sensitive CoNS (MSCoNS) was detected in 79 (58.5%) isolates and methicillin resistant CoNS (MRCoNS) in 56 (41.5%) isolates. Conclusion: This study demonstrated the occurrence of various species of CoNS in our healthcare set up with varying antimicrobial susceptibility pattern. Therefore, there is a need for accurate identification to species level by simple, inexpensive methodology and their antibiogram.

Bacterial coinfections in COVID: Prevalence, antibiotic sensitivity patterns and clinical outcomes from a tertiary institute of Northern India.

Bacterial coinfections are a leading cause of morbidity and mortality during viral infections including corona virus disease (COVID-19). The COVID-19 pandemic has highlighted the need to comprehend the complex connection between bacterial and viral infections. During the current pandemic, systematic testing of the COVID-19 patients having bacterial coinfections is essential to choose the correct antibiotics for treatment and prevent the spread of antimicrobial resistance (AMR). This study was planned to study the prevalence, demographic parameters, comorbidities, antibiotic sensitivity patterns, and outcomes in hospitalized COVID-19 patients with bacterial coinfections. The COVID-19 patients having bacterial coinfections were selected for the study and analyzed for the prevalence, antibiotic sensitivities, comorbidities, and clinical outcomes. The bacterial isolates were identified and the antibiotic susceptibility testing was performed according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Of the total 1,019 COVID-19 patients screened, 5.2% (n = 53) demonstrated clinical signs of bacterial coinfection. Escherichia coli were the most common isolate followed by Pseudomonas aeruginosa and Klebsiella spp. among the gram-negative bacterial infections. Coagulase-negative Staphylococcus species (CONS) and Staphylococcus aureus were most common among the gram-positive bacterial infections. The antibiotic sensitivity profiling revealed that colistin (99%), imipenem (78%), and fosfomycin (95%) were the most effective drugs against the gram-negative isolates while vancomycin (100%), teicoplanin (99%), and doxycycline (71%) were most potent against the gram-positive isolates. The analysis of the clinical parameters and outcomes revealed that among the COVID-19 patients with bacterial coinfections, the mortality rate was higher (39%) than the control group (17%) (P-value < 0.001). This study reveals the significantly increased rates of bacterial coinfections among COVID-19 patients which may lead to an increase in mortality. This study will guide the physicians at the primary level on the rational and correct usage of antibiotics in such COVID cases. Hence, systematic testing of COVID-19 patients with bacterial coinfections is the need of the hour to decrease the mortality rate and limit the spread of AMR.